Contents
This picture, The Geographer, Geographer, is reproduced with permission from the Städelsches Kunstinstitut, Frankfurt am Main, Germany. It was painted by the famous utchman !ohannes "ermeer "ermeer of elft in #$$%&#$$' and is belie(ed to be of the eminent microscopist and microbiolo)ist (an *eeuwenhoek, also of elft and also + years old. "an *eeuwenhoek presumably commissioned the portrait and or)ani-ed the obects of science and )eo)raphy. It is appropriate for the frontispiece because it shows (an *eeuwenhoek as a /Self/ planning to carry out a measurement with the di(iders in his ri)ht hand on the chart laid out below. The Self is controllin) its brain to brin) about this planned action as in the countless (oluntary actions we do e(ery day.
John C. Eccles
How the SELF Controls Its BRAIN
Sprin)er&"erla)
0erlin 1eidelber) 2ew 3ork *ondon 4aris Tokyo 1on) Kon) 0arcelona 0udapest
Sir !ohn 5. 6ccles
5a/a la Gra 51&$$7$ 5ontra Swit-erland Frontispiece8 The Geo)rapher by !an "ermeer "ermeer (an elft #$+9&#$:
5an(as +. ; < 7$. $ cm
owned by Städelsches Kunstinstitut, Frankfurt
= 0lauel>Gnamm&?@TAT16K, 0lauel>Gnamm&?@TAT16K, 4icture 2o. $:+$
Bith 9 Fi)ures IS02 +&7;&$9';&: Sprin)er&"erla) 0erlin 1eidelber) 2ew 3ork IS02 ;&+%:&$9';&: Sprin)er&"erla) 2ew3ork 0erlin 1eidelber) 5I4 data applied for This work is subect subect to copyri)ht. copyri)ht. ?ll ri)hts are reser(ed, whether the who le or part of the material is concerned, specificall specificallyy the ri)hts of translation, reprintin), reuse of illustrations, recitation, broadcastin), reproduction on microfilm or in any other way, and stora)e in data banks. uplication of this publication or parts thereof is permitted only under the pro(isions of the German 5opyri)ht *aw of September ', #'$, in its current (ersion, and permission for use must always be obtained from Sprin)er&"erla). "iolations are liable for prosecution under the German 5opyri)ht *aw. = Sprin)er&"erla) Sprin)er&"erla) 0erlin 1eidelber) #''7 4rinted in Germany The use of )eneral descripti(e names, re)istered names, trademarks, etc. in this publication does not imply, e(en in the absence of a specific statement, that such names are e
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Dedicated in admiration and gratitude to my dear friend Dr. Dr. h. c. mult. Heinz Götze on the wonderful occasion of his !th "irthday
Shakespearian Dualism
My brain, I/ll pro(e the female to my soul, My soul, the father8 and these two be)et ? )eneration )eneration of still&breedin) thou)htsE ?nd these same thou)hts, people this world In humours, like the people of this world, For no thou)ht is contented. Billiam Shakespeare, #ichard $$ , ?ct ", Scene
Preface The contro(ersial title of this book has to be re)arded as a challen)in) hypothesis that has been de(eloped in the successi(e sta)es of scientific in(esti)ations described in 5hapters 7&#;. It is much to be re)retted that most scientific in(esti)ators of the brain are still inducti(ists, belie(in) that science should be practised by accumulation of e
It is of )reat si)nificance that the key hypothesis has been e
Contents
The 4roblem ualist&interactionismHMy ualist&interactionismHMy Story @ecent Theoretical Theoretical Studies on the Mind&0rain 4roblem 2ew *i)ht on the Mind&0rain 4roblem8 1ow Mental 6(ents 5ould Influence 2eural 6(ents 6(ents 5ause 5ause 2eural 2eural 6(ents 6(ents ?nalo)ous ?nalo)ously ly to the 4robability 4robability Fields of 5. o Mental 6(ents Luantum MechanicsJ 1ypothesis of Mind&0rain Interaction in the 5erebral 5orte< 6. ? Cnitary 1ypothesis 7. The 6(olution of 5onsciousness 5onsciousness 8. The 6(olution of 5omple
Glossary
Acknowledgements I am much indebted to r 1ein- Gt-e for arran)in) for the publication of this book by Sprin)er&"erla), with their e
2ew li)ht li)ht on the the mind&b mind&brai rainn problem problem88 how menta mentall e(ents e(ents could could influe influence nce neura neurall e(ents, e(ents, in Comple edited by 1. 1aken Sprin)er, 0erlin, 1eidelber) #'%$. For the benefit of readers there is repetition of some fi)ures and references. o mental mental e(ents cause neural e(ents e(ents analo)ously analo)ously to the probability probability fields of uantum mechanicsJ, 2roc. #oy. &oc. &oc. %ondon 99:, 7##&79% #'%:. $ ? unitary hypothesis of mind&brain interaction in the cerebral corte<, 2roc. #oy. &oc. %ondon 97;, 7++&# #'';. : The e(olution of consciousness, 2roc. 1at. -cad. &ci. &ci. 89, :+9;&:+97 #''9. ' Bith Bith F. F. 0eck 0eck Luantum Luantum aspects aspects of brain acti(ity acti(ity and the role role of consciousnes consciousness, s, 4roc. 4roc. 1at. -cad. &ci. 89, ##+:&##+$# ##+:&##+$# #''9. &ystems/ &ystems/ 0perational 0perational -pproaches -pproaches in 1euro"io 1euro"iology logy,, 2hysics 2hysics and Computers, Computers,
1 The Problem 6ach wakin) day is a sta)e dominated for )ood or ill, in comedy, comedy, farce or tra)edy, by a /dramatis persona/, the /self/. ?nd so it will be until the curtain drops. This self is a unity. The continuity of its presence in time, sometimes hardly broken by sleep, its inalienable /interiority/ in sensual space, its consistency of (iew&point, the pri(acy of its e
1.1 Introduction
This poetic and (i(id e
I ha(e lon) been concerned with a problem that has been e
1.2 !potheses "elating to the #ind$%rain Problem
It is not possible here to )i(e a detailed appraisal of the immense philosophical literature on the mind&brain problem, or the body&mind problem. Fortunately this has been done in a masterly manner by 4opper 4opper and 6ccles #'::, 5hapters 4# and 4+&4. 1e has critically sur(eyed the historical de(elopment of the problem from the earliest records of Greek thou)ht. I will be)in with a simple description and dia)ram of the principal (arieties of this e
mind has no direct access to the body. ?ll interactions with the body are mediated by the brain, and furthermore only by the hi)her le(els of cerebral acti(ity.
Figure 1.1
Figure 1. 2
? tabular representation of the three worlds that comprise all e
? schematic representation of the (arious theories of brain and mind.
For our present purpose it is of (alue to clarify the ar)uments Fi)ure #.# by de(elopin) an e
•
4orld * is the whole material world
of the cosmos, both inor)anic and or)anic, includin) all of biolo)y, e(en human brains, and all man&made obects. 4orld 5 is the world of conscious e
•
4orld 6 is
the world of human creati(ityHfor e
1.& #aterialist Theories of the #ind$%rain Problem
The domina dominant nt theori theories es of the mind&b mind&brai rainn relati relations onship hip that that are today today held held by neuros neuroscie cienti ntists sts are purely purely materialistic in the sense that the brain is )i(en complete mastery 4ribram #':#E @ensch #':#, #':7E 0arlow #':9E oty #':E 0lakemore #'::E Mountcastle #':%E 6delman #':%, #'%'E 5han)eu< #'%. The e
There is a denial of the e
This is a (ery ancient theory de(eloped by the earliest Greek philosophers, who proposed that /soul is min)led with e(erythin) e(erythin) in the whole uni(erse/ uni(erse/. Such philosophers philosophers as Spino-a Spino-a and *eibni- espoused (arious forms of panpsychism. 6ssentially their belief was that all thin)s had an inner psychical aspect and were material in their outer aspect. 4anpsychism has e(en attracted modern biolo)ists such as Baddin)ton #'$', @ensch #':#, and 0irch #':7, because it offers such an attracti(e solution to the problem of the e(olutionary ori)in of consciousness, namely that consciousness was associated with all matter in some protopsychic state and was merely de(eloped with the increasin) comple
6piphenomenalism differs from panpsychism in that mental states are attributed only to animals that e
brain influence is not defined, but one (iew is that mind states run parallel with brain states, much as in panpsychism see 4opper and 6ccles 6ccles #'::, 4art I, Section 9;. 1.&.( The Ps!choph!sical Identit! Theor!) or the Central State Theor!
*ike panpsychism this theory was first de(eloped by Greek philosophers, and the two theories ha(e often been linked, for e
I propose now to consider the biolo)ical implications of the three materialist theories that admit the e
#M and Borld # M relates to Borld 9. 2e(ertheless the performance of the brain in controllin) beha(iour is entirely within the physical structures of the brain. 2o causal effecti(eness of Borld 9 is admitted other than that of pert pertai aini nin) n) to Borld rld #M. Thus Thus the the clos closed edne ness ss of Borld rld # is as abso absolu lute te as with with panp panpsy sych chis ism m or epiphenomenalism. These three theories assert the causal ineffecti(eness of Borld 9. 3et this is an undeniable fact see 4opper and 6ccles #'::, 4art I, Sections 9; and 9+, ialo)ue "IIIE and 5hapters &#; of the present book. There is firstly its emer)ence and then its pro)ressi(e de(elopment with the )rowin) comple
This theory is the most ancient formulation of the mind&brain problem, bein) in some form )enerally accepted by Greek thinkers from 1omer onwards 4opper and 6ccles #'::, 4art I, Sections 7+ and 7$. It was de(eloped by escartes, who attempted to define a detailed mode of operation that led to it bein) bein) reected in fa(our of some form of parallelism. In its modern form it is distin)uished from all parallelistic theories precisely by the reuirement of the openness of Borld Borld # to Borld 9 e(ents Fi)ure #.+. The essential feature of dualist&interactionism is that the mind and brain are independent entities, the brain bein) in i n Borld Borld # and the mind in Borld Borld 9, and that they interact by uantum physics, ph ysics, as will be described in 5hapters ' and #; and as illustrated in Fi)ures '. and #;.9. There is a frontier, and across this frontier there is interaction in both directions, which can be concei(ed as a flow of information, not of ener)y. Thus we ha(e the e
Great display is made by all (arieties of materialists that their brain&mind theory is in accord with natural law as it now is. 1owe(er, this claim is in(alidated by two most wei)hty considerations. :irstly, nowhere in the laws of physics or in the laws of the deri(ati(e sciences, chemistry and biolo)y, is there any reference to consciousness or mind. Shapere #':7 makes this point in his stron) criticisms of the panpsychist hypothesis of @ensch #':7 and 0irch #':7, in which it was proposed that consciousness or protoconsciousness is a fundamental property of matter. @e)ardless of the comple
Figure 1.3 ?n
information information flow dia)ram for brain&mind brain&mind interaction. interaction. The three components components of Borld Borld 5, outer sense, inner sense, sense, and the e)o, or self, are dia)rammed dia)rammed with their communications communications shown by arrows arrows.. ?lso shown are the lines of communication across the interface between Borld # and Borld 9, that is, from the liaison brain to and from these Borld 9 components. The liaison brain has the columnar arran)ement indicated by the 'ertical "ro7en lines. It must be ima)ined that the area of the liaison brain is enormous, with open modules numberin) o(er a million, not ust the two t wo score depicted here.
statement that consciousness emer)es at a specified le(el of comple
This is an effecti(e reductio ad a"surdum. This stricture applies to all of the materialist theories of the mind. 0ut now in 5hapter ' of the present book the application of uantum physics to the ultramicrostructure and func & tion of the brain neocorte< re(eals that mental action could increase the neural responses by increasin) the uantum probability of e
2 Dualist$interactionism-#! Stor! This chapter relates to a philosophy that has been inte)ral with my intellectual life since my early years as a medical student. I had been confronted by an irreli)ious philosophy of monist&materialism that I could not accept. In my wide readin) of philosophy from the pre&Socratics to the present, I had come to the dualist philosophy of escartes with his res eterna and res cogitans. It )a(e a secure status to the human soul or self, but his interaction story was completely erroneous. In fact from my readin) of philosophy I disco(ered a per(asi(e i)norance of the brain at the subtle subtle le(el at which it could relate to conscious conscious e
In my effort to ima)ine how the cerebral corte< could relate to mind, I had perforce to concentrate on the or)ani-ation of the cortical neurons in comple< functional networks with synapses as )enerators of neuronal dis& char)es. The patterns of neuronal acti(ity would be due to the (ery recent synaptic inputs on to the patterns of structural specificity, both inherited and acuired. 5artesian dualism necessarily in(ol(ed the problem of how mind and brain could interact in willed acts and in perception. It had been reco)ni-ed that consciousness in(ol(ed the liaison of mind with brain, and the elec& troencephalo)ram showed that the cerebral corte< had to be (ery acti(e in a selecti(e way. The intense dri(en acti(ity of an epileptic sei-ure led to an immediate loss of consciousness. These concepts relate the spatio& temporal patterns in the neuronal networks to the specific e
Cnfortunately the neuronal structure of the cerebral corte< was poorly understood in #'#, so that it was only possible possible to consider consider the neuronal neuronal networks in )eneral )eneral terms. The hypothesis hypothesis was proposed that the mind achie(es liaison with the brain by e
The in(itation to )i(e in #'9 the Baynflete *ectures at A
In the same 5hapter : a detailed description of all the in(esti)ations on the cerebral corte< did not disclose a challen)e to Sherrin)ton/s supposition. Sherrin)ton #'# refers to mind as the non&sensual concept, sayin)8 Aur mental e
This This e
0ut the key problem in perception has so far remained beyond this discussion. Be may ask8 1ow can some specific spatio&temporal pattern of neuronal acti(ity in the cerebral corte< e(oke a percept in this mindJ Be shall shall return to this perple
Followin) my #'+ book there was a lon) philosophic inter(al. I still belie(ed in dualist&interaction and in the uniueness of the self. 1owe(er, my interests were concentrated on neuroscience, which pro(ided the scientific challen)e of my life, particularly the #7 years at the ?ustralian 2ational Cni(ersity at 5anberra #'9&#'$$. I did not en)a)e in philosophical ad(entures on dualist&interaction, but I accepted in(itations to lecture and write on the mind&brain problem, which had remained much as I left it in #'9. ?lso e
2.( %rain and Conscious 'perience
In #'$7 there was an attracti(e opportunity to return to the brain and consciousness when I or)ani-ed an international symposium in the 4ontifical ?cademy of Science in @ome, under the title /0rain and 5onscious 6<& 6< & perience/. There was a wonderful )atherin) of brain scientists, but our philosophical performance was disappointin). I (ery much missed Karl 4opper. In 5hapter 9 of the Symposium, published by Sprin)er&"erla) 6ccles #'$$, I brou)ht to)ether all the scientific findin)s on the neurons of the cerebral corte<, which had been studied usin) the most ad(anced techniues by 4hillips, 5reut-feldt, *u<, Klee, ?rmstron), *i, and 4urpura. It was remarkable to corroborate the su))estion of Sherrin)ton uoted abo(e that cortical neurons share in the same properties as other neurons. So the construction of neural networks has )ood e
There was a )radual reco(ery o(er many years with no outstandin) features until #'%7. I chose #'$' as my startin) point here because I was in(ited to )i(e the Foerster *ecture at 0erkeley with the remarkable title The 0rain and the Soul/. My lecture drew the lar)est audience I ha(e e(er had. The assi)ned lecture room for 9 ;;; was completely filled, so we had the initial disorder of mo(in) to the lar)est audience room in 0erkeley with o(er + ;;; places. I was a bit apprehensi(e of the title, wonderin) if it was chosen to lead me on I accepted it as a challen)e. In the past I had been reluctant to use the reli)ious word, soul, )reatly preferrin) the philosophical word, self. In my lecture also I was careful to establish my academic credentials by buildin) up the anatomical and histolo)ical structure of the brain and also the neuronal machinery of the cerebral corte< with the neuronal nets, states of consciousness, and freedom of the will. Then came the +&world concept of 4opper, with special emphasis on
cultural e(olution with lan)ua)e, and then the concept of the self, with self&awareness and death&awareness. Anly then did I come to the soul8 I belie(e that my e
There was an enthusiastic discussion for o(er an hour, so I felt satisfied with my reappearance. There were two remarkable aftermaths. An the ne
It must be assumed that there are dynamic patterns in the de(elopment and interaction of modules, as is simply illustrated in Fi)ures 9.9, $., and $.##. Thus it is proposed that the self&conscious mind e
In ialo)ue " of 4opper and 6ccles #':: there is e
that, and blendin) to)ether the results of readouts of many different areas in the liaison brain. In that way the self& conscious mind achie(es a unity of e
Figure 2.1 2eurons and
their synaptic connections, conne ctions, a 6i)ht neurons from Gol)i preparations of the three superficial layers of frontal corte< from a month&old child. Small 0, 5 and medium , 6 pyramidal cells are shown with their profuse dendrites co(ered with spines. ?lso shown are three other cells ?, F, K, which are in the )eneral cate)ory of Gol)i type II with their locali-ed a
The mind&brain interaction was treated at se(eral places in my Gifford *ectures, The 1uman Mystery/ 6ccles #':' and The 1uman 4syche/ 6ccles #'%;, but the main theme was concentrated on the )reat philosophical issues of our nature and and our destiny with the scope of natural theolo)y. theolo)y. 1owe(er, I did attempt to )o further in de(elopin) the hypotheses of the self&conscious mind in relation to the brain8
9.9 In this schema of the cerebral corte< looked at from abo(e, the lar)e pyramidal cells are represented as dott that are arran)ed in clusters, each cluster correspondin) to a column or module. The arrows symboli-e impulse dischar)es alon) hundreds of lines in parallel, which are the mode of e
Figure
The self&conscious mind is acti(ely en)a)ed in readin) out from the multitude of liaison modules RFi)ure #.+ that are lar)ely in the dominant cerebral hemisphere. The self&conscious mind selects from these modules accordin) to attention and interest, and from moment to moment inte)rates its selection to )i(e unity e(en to the most transient e
espite the impressi(e description of the comple< modular operations of the cerebral corte<, it was not possible to )i(e any answer to the uestion of the /how/ of this operation. 2euronal comple
I immediately communicated with Mar)enau, whom I already knew, and we had a stimulatin) correspondence. Meanwhile I had written a most appreciati(e re(iew of his book b ook for :oundations of 2hysics. It was ust at this time that 4rofessor 4 rofessor 1erman 1aken of Stutt)art in(ited me to a conference that he was or)ani-in) for $&## May #'%, at the attracti(e establishment at Schloss 6lmau in Southern 0a(aria. The conference was on the )eneral theme of /5omple< Systems8 Aperational ?pproaches in 2eurobiolo)y, 4hysics and 5omputers/. It )a(e me the opportunity to present my paper /2ew *i)ht on the Mind&0rain 4roblem8 1ow Mental 6(ents 5ould Influence 2eural 6(ents/. 4rofessor 1aken was most encoura)in) that I should )i(e a full presentation of the new de(elopments, so I was )i(en two hours on the pro)ramme for lecture and discussion, but e(en that was not enou)h. The discussion was
resumed for an hour or so after dinner I was (ery happy at the )ood reception )i(en by the )roup of about $; physical scientists, computer theorists, and other scientists. My paper was published in the conference (olume by Sprin)er& "erla), "erla), and appropriately I ha(e included it as the first of my published papers in this book 5hapter 7. "eferences to Chapters 1 and 2 ?rmstron), . M. #'%# The 1ature of 3ind 5ornell Cni(ersity 4ress, Ithaca 23. 0arlow, 1. 0. #':9 Sin)le units and sensation8 ? neuron doctrine for perceptual psycholo)yJ, 2erception a nd 6ccles, !. 5. #''9 Luantum aspects of consciousness and the role 2erception #, +:#&+'7. 0eck, F, and of consciousness, 2roc. 1at. -cad. &ci. %', ##+:&##+$#. 0eloff, !. #'$9 The Eistence of 3ind Mec)ibbon Mec)ibbon and Kee, *ondon. 0irch, 5. #':7 5hance, necessity and purpose, in &tudies in the 2hilosophy of iology, edited by @ !. ?yala and T. ob-hansky Macmillan, *ondon, pp. 99&9+'. 0lakemore, 5. #':: 3echanics 3echanics of the 3ind 3ind 5ambrid)e Cni(ersity 4ress, 5ambrid)e. 0un)e, M. #'%; The 3ind(ody 2ro"lem 4er)amon, Aongresses >ongresses f?r 2hilosophic, 2hilosophic, "ol. # 1erder, "ienna, pp. 9&+. 4opper, K. @. #':9 0"@ecti'e >nowledge/ -n E'olutionary E'olutionary -pproa -pproach ch 5larendon, A
*ondon, pp. 97#&9%.
Schrdin)er, 6. #'% 3ind and 3atter 5ambrid)e Cni(ersity 4ress, 5ambrid)e. Searle, !. @. #'%7 3inds, rains and &cience 0ritish 0roadcastin) 5orporation, *ondon. Searle, !. @. #''9 The #edisco'ery of the 3ind MIT 4ress, 5ambrid)e M?. Shapere, . #':7 iscussion of @ensch, in &tudies in the 2hilosophy of iology,
edited by F. !. ?yala and T. ob-hansky Macmillan, *ondon. Sherrin)ton, 5. S. #'7; 3an on His 1ature 5ambrid)e Cni(ersity 4ress, *ondon. Second edition #'#. Smart, !. !. 5. #'$+ 2hilosophy 2hilosophy and &cientific &cientific #ealism @outled)e and Ke)an 4aul, *ondon. Sperry, @. B. #':: Forebrain commissurotomy and conscious awareness, J. 3ed. J. 3ed. 2hil. 5, #;# $. Sperry, @. B. #'%; Mind&brain interaction8 Mentalism, yesE dualism, no, 1euroscience 1euroscience , , #'&9;$. S-entN)othai, !. #': The /module/ concept in cerebral corte< architecture, rain rain network of the cerebral corte<. ? functional #es. 9, 7:&7'$. S-entN)othai, !. #':% The neuron network interpretation, 2roc. #oy. #oy. &oc. %ondon 9;#, 9#'&97%. S-entN)othai, !. #':' *ocal neuron circuits of the neocorte<, in The 1eurosciences. 1eurosciences. :ourth &tudy &tudy 2rogram, 2rogram, edited by
F. A. Schmitt and F. G. Barden Barden MIT 4ress, 5ambrid)e M?. Thorpe, B. 1. #':7 -nimal 1ature and Human 1ature Methuen, *ondon. Thorpe, B. 1. #':% 2urpose in a 4orld 4orld of Chance A
& "ecent Theoretical Studies on the #ind$%rain Problem In recent years the literature on the mind&brain problem has become enormous and di(erse. ?ny attempt at uotation of all important contributions would produce disor)ani-ed chapters. So I ha(e chosen to present in this chapter some critical abstracts of the literature published in many books by leadin) authorities. For ease of reference the sections are arran)ed alphabetically by author. ?uthors are selected for discussion because their publications relate specifically to the chapters of this book. Further reference to this literature will be made throu)hout the book. &.1 6. P. Changeu) Neuronal Man: The Biology of Mind, 1/5*
Much of 5han)eu
This appears to be a dualism that I would not reect at first, but then it appears as a subtle e
I also a)ree. The mental obect is identified in se(eral specific cortical areas. Then there follows for o(er two pa)es pp. #+% a neuronal fantasia with no mention of how a /mental obect/ becomes mental. In /4roblems of 5onsciousness/ 5han)eu< writes8 Bhile we are awake and attenti(e, we appreciate and pursue the formation of precepts and concepts. Be can store and recall mental obects, link them to)ether, and reco)ni-e their resonance. Be are conscious of all this in our unendin) dialo)ue with the outside world, but also within our own inner world, our /me/, p. #7
Bhen considerin) the role of the reticular acti(atin) system that was shown by Moru--i and Ma)oun to pro(ide the essential back)round back)round acti(ity of the cerebral corte<, 5han)eu< 5han)eu< states8
5onsciousness, then, corresponds to a re)ulation of the o(erall acti(ity of cortical neurons and, more )enerally, of the entire brain. ? few small )roups of neurons in the brainstem, with their cell bodies centrally situated, e
?s 5han)eu< e
I )i(e these e
0ut is this not the pro)ram of dualist&interactionismJ 5han)eu< seems to ha(e missed the way that was earlier described but is later de(eloped fully in 5hapters 7H' of the present book. This /mental obects/ chapter finishes with much speculation on the neuronal composition of mental obects, e(en with /homuncular/ components The combinational possibilities pro(ided by the number and di(ersity of connections in the human brain seem uite sufficient to account for human capabilities. There is no ustification for a split between mental and neuronal acti(ity. p. 9: It seems uite le)itimate to consider that mental states and physiolo)ical or physico&chemical states of the brain are identical. p. 9:
So 5han)eu< lapses into a simple identity theory without any more philosophical ado. Be must first construct within our brain an ima)e of /man/, an idea, like a model, that we can contemplate. p. 9%7 Man has no lon)er need of a Spirit. It is enou)h for him to be /2euronal Man/. p. #$'
Bhy not also /Mindful Boman/J &.2 7. Crick and C. Consciousness) 1//:
8och)
Towar wards a
9eurobiological
Theor! of
Implicit in the concepts of 5rick and Koch is the identity theory of Fei)l that has been described in 5hapter #.+.7 and Fi). #.9. They state8 Aur basic hypothesis at the neural le(el is that it is useful to think of consciousness as bein) correlated with a special type of acti(ity of perhaps a subset of neurons in the cortical system ... ?t any moment consciousness corresponds to a particular type of acti(ity in a transient set of neurons that are a subset of a much lar)er set of potential candidates. p. 9$$ Aur basic idea is that consciousness depends crucially on some form of rather short&term memory and also on some form of serial attentional mechanism. This attentional mechanism helps sets of the rele(ant neurons to fire in a coherent semioscillatory way, probably at a freuency in the 7;&:; 1- ran)e, so that a temporary )lobal unity is imposed on neurons in many different parts of the brain. These oscillations then acti(ate short&term workin) memory. p. 9$+
0ut there is much e(idence that mental attention can cause neural acti(ation, as has been described by 0eck and myself 0eck and 6ccles #''9 and 5hapters ' and #;.$ of the present book. 5rick and Koch can now use these new disco(eries to account for the choice of the most salient obects for attention with acti(ation of the most appropriate neurons to )i(e
Rthe best interpretation of which we become aware. The information about a sin)le obect is distributed about the brain. There has, therefore, to be a way of imposin) a temporary unity on the acti(ities of all the neurons that are rele(ant at that moment. Incidentally we see no rea & son at all why this )lobal unity should reuire fancy uantum effects. The achie(ement of this unity may be assisted by a fast attentional mechanism, the e
So far so )ood, but their seuel cannot be accepted. It concerns machines ha(in) comple< rapidly chan)in) and hi)hly parallel acti(ity. Bhen we can both construct such machines and understand their detailed beha(ior much of the mystery of consciousness may disappear. p. 9:7
This can be dismissed as science fiction of a blatant kind. @eference should be made to the sections in this chapter on 4enrose +.: and Searle +.% and +.' and to 5hapter #;.: for a criticism of such artificial intelli)ence machines. &.& 7. Crick and C. 8och) Consciousness) Scientific American, 1//2
?fter an introductory discussion lar)ely co(ered by the precedin) paper, 5rick and Koch state8 There may be a (ery transient form of fleetin) awareness that represents only rather simple features and does not reuire an attentional mechanism. From this brief awareness the brain constructs a (iewer¢ered representation H what we see (i(idly and clearlyHthat does reuire attention. This in turn probably leads to three&dimensional obect representations and thence to more co)niti(e ones. p. ##9
I think that these are important statements su))estin) four le(els of consciousness. I also a)ree with their closin) statement8 Ance we ha(e mastered the secret of this simple form of awareness, we may be close to understandin) a central mystery of human life8 how the physical e(ents occurrin) in our brains while we think and act in the world relate to our subecti(e sensationsHthat is, how the brain relates to the mind. p. ##:
There appears to be no insistence on the identity theory and no denial of dualism. The way is open to the new findin)s and hypotheses of 0eck and myself 0eck and 6ccles #''9 and 5hapter ' of the present book. &.( D. C. Dennett) Consciousness Explained, 1//1
1as ennett dunnitJ 1uman consciousness is ust about the last sur(i(in) mystery. p. 9# Consciousness ss Eplained Eplained To start with I uote from his It is still a mystery at the end of his 7$%&pa)e book Consciousne initial summary8
Be ha(e found four reasons for belie(in) in mind stuff. The conscious mind, it seems, cannot ust be the brain, or any proper part of it, because nothin) in the brain could # be the medium in which the purple cow is renderedE 9 be the thinkin) thin), the $ in in /I think, therefore I am/E + appreciate wine, wine, hate racism, lo(e someone, be a source of mattering 7 act with moral responsibility. ?n acceptable theory of human consciousness must account for these four compellin) )rounds for thinkin) that there must be mind stuff. pp. +9&++
This is dualism8 brain and mind. 3et 3et this section leads strai)ht on to the section headed /Bhy ualism is Forlorn/8 The pre(ailin) wisdom, (ariously e
*et us concentrate on the returned si)nals, the directi(es from mind to brain. These, e hypothesi, are not physicalE they are not li)ht wa(es or sound wa(es or cosmic rays or streams of subatomic particles. 2o physical ener)y or mass is associated with them. 1ow, then, do they )et to make a difference to what happens in the brain cells they must affect, if the mind is to ha(e any influence o(er the bodyJ ? fundamental principle of physics is that any chan)e in the traectory of any physical entity is an acceleration reuirin) the e
0ut now in 5hapter ' of the present book 0eck and I establish that there is no such flaw, so dualism is not forlorn any lon)er ennett makes an interestin) comment on p. +'8 Some brain researchers today would ne(er dream of mentionin) the mind or anythin) /mental/ in the course of their professional duties. For other, more theoretically darin) researchers, there is a new obect of study, the mind>brain. This newly popular coina)e nicely e
ennett is here e
ennett )i(es this brief initial sketch of his theory8 There is no sin)le, definiti(e /stream of consciousness/, because there is no central 1eaduarters, no 5artesian Theater where /it all comes to)ether/ for the perusal of a 5entral Meaner. Instead of such a sin)le stream howe(er wide, there are multiple channels in which specialist circuits try, in parallel pandemoniums, to do their (arious thin)s, creatin) Multiple rafts as they )o. Most of these fra)mentary drafts of /narrati(e/ play short&li(ed roles in the modulation modulation of current acti(ity but some )et promoted to further func tional roles, roles, in swift swift succession, succession, by the acti(ity of a (irtual machine in the brain. p. 97 They are often opportunistically enlisted in new roles, for which their nati(e talents more or less suit them. The result is not bedlam only because the trends that are imposed on all this acti(ity are themsel(es the product of desi)n. Some of this desi)n is innate, and is shared with other animals. 0ut it is au)mented, and sometimes e(en o(erwhelmed in importance, by micro&habits of thou)ht that are de(eloped in the indi(idual, partly idiosyncratic results of self&e
This series of do)matic statements is the be)innin) of ennett/s Multiple rafts Theory. I ask, is this a theory of consciousnessJ ennett apparently reali-es this when he states8 I ha(e been coy about consciousnes consciousnesss up to now. Cntil the whole theory&sketch theory&sketch was assembled, assembled, I had to deflect deflect such doubts, but at last it is time to )rasp the nettle, and confront consciousness itself, the whole mar(ellous mystery. ?nd so I hereby declare that 36S, my theory is a theory of consciousness. ?nyone or anythin) that has such a (irtual machine as its control system is conscious in the fullest sense, and is conscious "ecause it has such a (irtual machine. p. 9%#
Ane hundred and se(enty pa)es later ennett states8 I ha(en/t replaced a metaphorical theory, the 5artesian Theater, with with a non&metaphorical /literal, /literal, scientific/ theory. ?ll I ha(e done, really, is to replace one family of metaphors and ima)es with another, tradin) in the Theater, the Bitness, the 5entral Meaner, the Fi)ment, for Software, "irtual Machines, Multiple rafts, a 4andemonium of
1omunculi. It/s ust a war of metaphors, you sayHbut metaphors are not /ust/ metaphorsE metaphors are the tools of thou)ht. p. 7
I am much dissatisfied by ennett/s do)matic creation, the Multiple rafts Model, because it discounts a uniue Self which is central to our e!une #''9, p. 77. &.* +. #. 'delman) The Rememered !resent, 1/5/
*et me first emphasi-e that I am not presentin) a re(iew of this monumental book. I would not dare My task is to try to describe 6delman/s efforts to )i(e a solution of the mind&brain problem. 1e concludes that it is at least feasible feasible to construct construct a detailed detailed and principled principled brain&based brain&based theory of consciousne consciousness. ss. 6delman starts out with a stark challen)e8 ?ny adeuate )lobal theory of brain function must include a scientific model of consciousness, but to be scientifically acceptable it also must a(oid the 5artesian dilemma. In other words, it must be uncompromisin)ly physical. p. #;
I should should read no furthe further r This This is the solut solution ion of reduct reduction ionist ist material materialism ism,, which which he calls calls /materia /materialis listt metaphysics/. 1e )oes on to state8 Scientific epistemolo)y must confront the issue of consciousness in terms of e(olution, de(elopment, brain structure, and the physical order as we know it. If the confrontation is to remain in the scientific domain, a dualistic solution or any form of 5artesian empiricism cannot be countenanced, Rbein) often accompanied by what mi)ht be called 5artesian shame. p. 9:% ?n e
This pre(ailin) critical atmosphere bleakly recalls an in(erse Inuisitorial de)radation There is no detailed structural or functional consideration. !ust network theories with identity theory will )i(e consciousness. 6delman writes a section entitled The insufficiency of functionalism with its basis on computational states of the brain. 0rains and consciousness are not based on Turin) machines.
6delman is de(oted to his Theory of 2euronal Group Selection T2GS, which is no more than an elaborate e
I would warn a)ainst takin) this identity too strictly8 it is philosophese not physics Bhen /The Model of 4rimary 5onsciousness/ is finally un(eiled on pp. #+&# it appears as a (ery sophisticated type of identity theory deri(ed from a )reat comple
This seems to me like a conurin) trick The subseuent account )i(es the proposed neural pathways. Great stress is placed on memory.
6delman has been de(oted to neural circuits the T2GS that form the identity with the e
I uote a (aluable introduction to /1i)her&Arder 5onsciousness/8 Speech allows the de(elopment of internal models and conceptual cate)ori-ations that can be time&independent as well as of enriched distinctions of the concept of self, leadin) to personhood. p. #%
6(idently we are /unknowin)ly/ enterin) dualism8 where else is the self or the personJ Cnfortunately 6delman has been misled by *ieberman #': in Hominid E'olution to )i(e an absurdly late de(elopment of lan)ua)e in relation to brain de(elopment, which came as early as Homo ha"ilis Tobias Tobias #'%+E Stebbins #'%9. To become conscious of consciousness, or directly aware, an animal human must ha(e a distinction of self from nonself that is to some de)ree time&independent. p. #%$ ?t this point, /self/ becomes a term referrin) to such a conceptual model and not ust to a biolo)ical indi(idual, as is the case for primary consciousness. p. #%:
Thus we are introduced introduced to personhood personhood.. Be are far from the materialis materialistt metaphysic metaphysicss proclaimed proclaimed in 6delman/s 6delman/s introduction Subecti(e features relatin) to self&awareness, first&person usa)e, meanin), and the like are ust thatHsubecti(e processes )oin) on in a person who has hi)her&order consciousness. p. #'7 The causal relations between physical and mental e(ents can be understood in terms of the hetero)eneity of consciousness arisin) as a special form of memory connected with the self&nonself distinctions that are related by reentry to percei(ed e(ents. p. #'7
This is dualist&interactionism. "olition reuires the awareness of a )oal and the ability to direct action and thus sensation and perception. p. #': It is on these imperfect means and on the rich affecti(e e
?ll these and other uotations present e
It is embarrassin) for 6delman to display his i)norance by accusin) these both of e
It has to be reco)ni-ed that !ud)e 1od)son brin)s a hi)hly skilled le)al mind to bear on the problem of the human mind with respect to such procedures as (olition, freedom, responsibility, and open choice. 5oncernin) mental mental e'ents, one can accept the initial statement that mental e(ents are the fully conscious e
5oncernin) perception, I will deal, in 5hapter #;., with the problems under the headin) of attention by which the mind selects and intensifies the e
1od)son writes well on the central role which mind has in the life and world of e(ery human bein)8 in an important sense it is the totality of each person/s world, it is basic to all knowled)e, and may well be the constructor not merely the knower kno wer of the common e
Mind is the totality, but we ha(e to reco)ni-e that it is much more e
Much that 1od)son writes on personal identity and the self is ust repeatin) the science fiction of 4arfit pp. 7;'&7#+ with brain transplants and re(ersible blocka)e of the corpus callosum etc. 4arfit is a reductionist. In sketches for a world (iew by 1od)son there is an account of escartes/s dualism of substance that I oin 1od)son in reectin). The concept of substance leads to a materialist aspect of the mind. I speak instead of the spiritual e
follow 4opper/s terminolo)y, and to identify two /worlds/8 the Borld # of the physical or obecti(e and Borld Borld 9 of the mental or subecti(e. p. 77 An p. 77' morality is discussed in a )ood ud)emental account with which I appro(e, e
&.; ". Penrose) The Emperor"s Ne# Mind, 1//1
This book is a sophisticated criticism of the e
My reaction is that we ha(e to )o on scientifically and philosophically, philosophically, and we can be )reatly encoura)ed by the pro)ress. There of course are many blind alleys that ha(e enormous attraction to computer technolo)ists, notably the artificial intelli)ence and robotics machines. I a)ree with 4enrose/s )eneral reection of such models of intelli)ence and consciousness. ? related proect is to study the properties of assumed neuronal networks, which can be modelled by computer technolo)y, and that e(en may )i(e an openin) to robotics. 4enrose asks two challen)in) uestions8 1ow is it that a material obect a brain can actually e'o7e consciousness' p. 7;
and, con(ersely8 1ow is it that a consciousness, by the action of its will, actually motion of material obectsJ p. 7;
influences the
apparently physically determined
These are the passi(e and acti(e aspects of the mind&body problem. It appears that we ha(e in /mind/ or, rather, in /consciousness/, a non&material /thin)/ that, on the one hand, is e(oked by the material world and, on the other, can influence it. p. 7;
It seems that 4enrose is satisfied with an e
4enrose asks the important uestion8 Bhat does consciousnes consciousnesss actually doJ . . . Bhat is it that we can do with conscious thou)ht that cannot be done unconsciouslyJ . . . Somehow, consciousness is needed in order to handle situations where we ha(e to form new ud)ements, and where the rules ha(e not been laid down beforehand. It is hard to be (ery precise about the distinction between the kinds of mental acti(ity that seem to reuire consciousness and those that do not. p. 7## The @udgement(forming @udgement(forming that I am claimin) is the hallmark of consciousness is itself somethin) that the ?I people would ha(e no concept of how to pro)ram on a computer. p. 7#9 I am puttin) forward the ar)ument here that it is this ability to di(ine or /intuit/ truth from falsity and beauty from u)liness, in appropriate circumstances, that is the hallmark of consciousness. p. 7#9
4enrose e
?fter much discussion 4enrose comes to a wise conclusion8 I cannot cannot belie(e belie(e that the anthrop anthropic ic ar)ument ar)ument is the real reason or the only reason for the e(olution of consciousness. There is enou)h e(idence from other directions to con(ince me that consciousness is of powerful selecti(e ad(anta)e, and I do not think that the anthropic ar)ument is needed. p. 7+7
In /Time elays of 5onsciousness/ p. 7+' 4enrose is uite ri)htly concerned with some of the findin)s of these searchin) in(esti)ations, but in part they in(ol(e technical problems, as yet unresol(ed, so they should not be discussed here. @eference @eference could be made to *ibet #'';, p. #% and the General General iscussion on pp. 9;:&9;'. 4enrose is of )reat interest because he concentrates at the end of his book on the )reat problems8 Some readers may, from the start, ha(e re)arded the /stron)&?I&supporter/ as perhaps lar)ely a straw man Is it not /ob(ious/ that mere computation cannot e(oke pleasure or painE that it cannot percei(e poetry or the beauty of an e(enin) sky or the ma)ic of soundsE that it cannot hope or lo(e or despairE that it cannot ha(e a )enuine autonomous purposeJ 3et science seems to ha(e dri(en us to accept that we are all merely small parts of a world )o(erned in full detail e(en if perhaps ultimately ust probabilistically by (ery precise mathematical laws. Aur brains themsel(es, which seem to control all our actions, are also ruled by these same precise laws. The picture has emer)ed that all this precise physical acti(ity is, in effect, nothin) more than the actin) out of some (ast perhaps probabilistic computationHand, hence, our brains and our minds are to be understood solely in terms of such computations computations . . . 3et 3et it is hard to a'oid an uncomforta"le feeling that there must always "e something missing from such such a picture. picture.
This is the picture of monist materialism that I ha(e been contendin) with and reectin) all my life. 4enrose )oes on to state8 5onsciousness seems to me to be such an important phenomenon that I simply cannot belie(e that it is somethin) ust /accidentally/ conured up by a complicated computation. It is the phenomenon whereby the uni(erse/s (ery e
My comment is that for each of us consciousness )i(es the e
&.5 6. ". Searle) Minds, Brains and Science, 1/52
Searle initially writes a simple philosophical story that I find attracti(e. 1e states that there is a temptation to down)rade the status of mental entities. So most of the recently fashionable materialist conceptions of the mind Hsuch as beha(iourism, functionalism, and physicalismHend up by denyin), implicitly or e
1owe(er, in 5hapters : and ' of the present book I show how wonderful scientific in(esti)ations resol(e this mystery, mystery, at least at the first sta)e of understandin). Searle states that it is somethin) somethin) of a scandal that contemporary contemporary discussions discussions in philosophy and psycholo)y ha(e so little of interest to tell us about consciousness. p. #$
Since that was written there has been a plethora of books and articles, some bein) uoted from in this chapter. 2ow the i)norance about the microstructure and microfunctions of the brain is a much )reater scandal. This knowled)e is essential for any scientific understandin) of the brain&mind problem 5hapters 7&' of the present book otherwise the brain indeed remains remains a meanin)less )rey and white )ook )ook Three Three other other featur features es beside besidess consc consciou iousne sness ss make make the mind&b mind&brai rainn problem problem diffic difficult ultHin Hinten tentio tional nality ity,, subecti(ity, subecti(ity, and mental causation p. #:. So far I am in )ood )eneral a)reement a)reement with SearleE then une
and he repeats8 6(erythin) 6(erythin) that matters for our mental life, all of our thou)hts thou)hts and feelin)s, feelin)s, are caused by processes inside the brain. p. #'
2otice the crudity of the brain reference. This is followed up by8 4ains and other mental phenomena are ust features of the brain and perhaps the rest of the central ner(ous system. p. #'
Searle is aware that this causal hypothesis will raise difficulties, so he relates it to other types of causation, for e
My dualist concept is that mental e(ents, such as intentions to mo(e, are initially in the mental e(ents relatin) to the cortical areas such as the supplementary motor area Fi)ure '. in which neural acti(ities are induced e(entually Fi)ures .9 and . in brin)in) about the desired mo(ements. Searle/s (iew at the end of his 5hapter # is that mind and body interact, but they are not two different thin)s, since mental phenomena ust are features of the brain. ?t the end Searle retracts from this hard position with his concepts of nai(e physicalism and nai(e mentalism. 1e states that mental phenomena really e
It is )ood to ha(e this assurance by Searle, but it is based on dubious neuroscience. 5hapters +, 7, and are not of (ital interest to my brain&mind story, but reference should be made to Searle/s 5hapter $ on freedom of the will. I a)ree with his statement8 Aur conception of human freedom is that it is essentially tied to consciousness. p. '7
1owe(er, the deterministic obection to free will is now eliminated by the ri)orous treatment of 0eck and myself 0eck and 6ccles #''9 and 5hapter ' of the present book. &./ 6. ". Searle) The Redisco$ery of the Mind, 1//2 It is surprisin) how close the themes in this book are to the theme of Searle/s #'%7 book, which ha(e been commented on in the pre(ious section. There is the same startlin) theme8 1ow could this )rey and white )ook inside my skull be consciousJ
Cnfortunately an attempted answer to this uestion in(ol(es an understandin) of the structure and function of the brain, particularly the neocorte< 5hapters 7&#; of the present book, that )oes far beyond the traditional neuroscience that Searle uotes Kuffler and 2icholls #':$E Shephard #'%+E 0loom and *a-erson #'%%. Searle/s biolo)ical naturalism is e
This is the uestion of an identity theorist who belie(es that somehow material happenings in a comple system generate mental e'ents 5hapter #.+.7 of the present book. 0ut this statement is without a scientific basis in classical physics. Instead it can be interpreted as a reuest for ma)ic Searle summari-es8 Aur world picture, thou)h e
0ut, as ust ar)ued, this is a statement reuirin) ma)ic. In 5hapter 9, /The @ecent 1istory of Materialism/, Searle states8 I ha(e been concerned not so much to defend or refute materialism as to e
Two Two uotations may )i(e Searle/s solution of the /body&mind problem/8 If we had an adeuate science of the brain, an account of the brain that would )i(e causal econsciousness works, and an adeuate knowled)e of how it works would remo(e the mystery p. #;9
Hat the e
@eference should be made to 5hapter : on the e(olution of consciousness of the present book for a scientific account of the e(olution of consciousness that Searle may be able to accept. 0ecause it brin)s in uantum physics it could help him in his remo(al of the ma)ic. It includes subecti(ity and can easily be e
If one had to describe the deepest moti(ation for materialism, one mi)ht say that it is simply a terror of consciousness. 0ut should this be soJ Bhy should materialists ha(e a fear of consciousnessJ Bhy don/t materialists cheerfully embrace consciousness as ust another material property amon) othersJ p. The deepest reason for the fear of consciousness is that consciousness has the essentially terrifyin) feature of subecti(ity subecti(ity.. Materialist Materialistss are reluctant to accept that feature because they belie(e that to accept the e
I belie(e all of this amounts to a (ery lar)e mistake, but this is because Searle accepts the identity theory, which I ha(e ust reected Searle/s Searle/s 5hapter 9 on the recent recent history history of materialis materialism m is most (aluable (aluable in )i(in) and critici-in) critici-in) a whole (ariety of materialisms, includin) beha(iourism, type identity theories, black bo< functionalism, stron) artificial intelli)ence, and eliminati(e materialism. Searle comes to an important conclusion8 It would be difficult to e
I think that this represents an important contribution of Searle, and I fully support his repeated su))estion that what we ur)ently need is an adeuate science of the brain. It is important that Searle raises this stark picture with its seuel8 . . . and unless we are blinded by bad philosophy or some forms of academic psycholo)y, we really don/t ha(e any doubts that do)s, cats, monkeys and small children are conscious, and that their consciousness is ust as subecti(e as our own. p. '
oes Searle not reali-e that he too is blinded by bad philosophy and that he needs dualism to resol(e his dilemmaJ Searle has reected dualism because he links it to the two kinds of substances of 5artesianism. 0ut I espouse the dualism of 4opper that is illustrated by Borlds # and 9 of Fi)ures #.# and #.+. Ane last comment is that I liked the co(erpiece by (an Go)h and would like to name it /Two Sel(es 5ommunin)/ &.1: ". <. Sperr!) 7orebrain Commissurotom! and Conscious Awareness) 1/;
The )reat achie(ement of Sperry in studyin) patients with transection of the corpus callosum is not a contro(ersial issue. Instead my concentration will be on the important contro(ersy to do with the mind&brain problem. There is an immense literature. I select first his #'$: paper, which was chosen for the (olume rain Circuits and :unctions of the 3ind, composed of essays in honour of Sperry. In essence, consciousness consciousness was concei(ed concei(ed to be a dynamic dynamic emer)ent emer)ent of brain acti(ity, acti(ity, neither identical with nor reducible reducible to the neural e(ents of which which it is mainly composed. composed. Further, consciousnes consciousnesss was not concei(ed as an epiphenomenon, inner aspect, or other passi(e correlate of brain processin), but rather as an acti(e inte)ral part of the cerebral process itself, e
control o(er the biophysical and chemical acti(ities at subordinate le(els. It was described initially as a brain model that puts /conscious mind back into the brain of obecti(e science in a position of top command ... a brain model in which conscious, mental, psychic forces are reco)ni-ed to be the crownin) achie(ement ... of e(olution./ It must be emphasi-ed at the outset that no direct empirical proof is a(ailable, any more than proof is a(ailable for the opposin) beha(iorist position. p. +%9
Sperry claims that a concept conceptual ual e
0ut this is not the case. Many years before 6ccles #'#, #'+, I was considerin) how intense dynamic acti(ity in the immense neuronal networks of the cerebral corte< could be recepti(e to the mental influences of the will. Sperry states that our concept of the emer)ent subecti(e properties and their causality are still, of course, at a )eneral abstract le(el. It remains by this and by any other theory thus far a(ailable to e
&.11 ". <. Sperr!) Science and Moral !riority, 1/52
Some years later Sperry wrote &cience and 3oral 2riority. In the earlier chapters of this book he was particularly concerned with (alues and science, as in these uotations8 I must take issue especially with the whole materialist&reductionist conception of human nature and mind that seems to emer)e from the currently pre(ailin) obecti(e analytic approach in the brain&beha(ior sciences. Bhen we are led to fa(or the implications implications of modern modern materialism materialism in opposition to older idealistic idealistic (alues in these and related matters, I suspect that we ha(e been taken, that science has sold society and itself a somewhat uestionable bill of )oods. p. 9% ?nother serious threat to cherished ima)es of human nature is the scientific reection of free will. p. +' This does not mean, howe(er, that there are cerebral operations that occur without antecedent cause. Man is not free from the hi)her forces in his own decision&makin) machinery. p. 7; 0ut to return to our central concern re)ardin) the impact of creepin) materialism in the brain&beha(ior sciences, and elsewhere, we can say in summary that it is possible to see today an obecti(e e
*ater I find Sperry more contro(ersial on the mind&brain action8 ? conceptual e
I fear that these crude analo)ical ar)uments are not acceptable scientifically. 1owe(er, in 5hapter ' of the present book an e
In callin) myself a mentalist, I hold subecti(e mental phenomena to be primary, causally potent realities as they are e
Af course I deny these statements. ualism is misunderstood by Sperry, as I shall show in i n 5hapter '. In the mid&si
Sperry apparently did not reco)ni-e that my comment was nau)htily ironic I was dedicated to the reality of consciousness with the title of my lecture /5onscious 6
Sperry claims that in #'9 he presented in terms of neuronal circuitry and concepts of neuroscience a the ory that seemed to counter and refute, for the first time on its own )rounds, the classic physicalist assumption of a purely physical determinacy of the central ner(ous system. Subecti(e mental phenomena had to be included. Mind&brain interaction was made a scientifica scientifically lly tenable tenable and e(en plausible plausible concept concept without without reducin) reducin) the ualitati(e ualitati(e richness richness of mental properties. properties. The o(erall aim of the paper, as in the 4opper and 6ccles (olume was to show that this reco)nition of the primacy of conscious mind as causal would alter profoundly the (alue implications of science which were bein) down& )raded by the then stron)ly dominant philosophy of reducti(e mechanistic materialism. pp. %#&%9
So I refer a)ain to my #'# 1ature article In his proposal of mental monism Sperry is )i(in) the cerebral corte< properties not reco)ni-ed in classical physics, as Stapp has pointed out. 1e is in the same difficulty as all the identity theorists. It is important to reco)ni-e that in our philosophy of dualism 4opper and I include much more than the self as e
I a)ree.
&.12 . P. Stapp) 4uantum Propensities and the %rain$#ind Connection) 1//1
The uantum physicist 1enry 4. Stapp has for se(eral years been thinkin) and publishin) on the mind&brain problem and has been inspired by the concepts of Billiam !ames, who wrote his monumental two&(olume 2rinciples of 2sychology ust o(er #;; years a)o. Stapp has achie(ed a remarkable synthesis of the philosophy of Billia Billiam m !ames !ames with with that that of the theore theoretic tical al physic physicist ist Berner rner 1eisen 1eisenber ber)) into into what what Stapp Stapp calls calls the 1eisenber)>!ames 1eisenber)>!ames model of consciousness. These uotations present his (iews8 ? conscious thou)ht is a real thin) that has an essential unity. It is not merely an a))re)ation of simpler parts. It is fundamentally one whole thin). 2othin) in classical physics can create somethin) that is essentially more than an a))re)ation a))re)ation of its parts. parts. 0ut a uantum actual e(ent does e
e(ents of this kind is one of the two fundamental reasons why one must turn to uantum theory to achie(e a rationally coherent understandin) of the mind&brain connection8 the reductionist classical&physics conception of nature is lo)ically unsuited to the task of accommodatin) essentially unified conscious thou)hts. The second fundamental reason why we must turn to uantum theory is that classical physics has, as is well known, no rational place for consciousness8 it is already lo)ically complete. The physical world, as it is concei(ed in classical physics, consists of nothing nothing "ut the (arious particles and fields, whose properties are, within that theory, spelled out completely. There is no lo)ical place within this conceptual structure for another kind of entity such as conscious8 if consciousness is put into the theory at all, then it must be put in simply /by hand/, rather than by (irtue of the lo)ical structure of the theory. The lo)ical situation situation in uantum theory is uite different8 different8 there is an absolute lo)ical need for somethin) else, such as consciousness. p. #7:;
This stron) statement of Stapp has been of )reat (alue to me in )i(in) reassurance in reectin) materialist reductionism and in buildin) a dualist theory of the mind&brain problem as can be seen in 5hapters 7H#; of the present book. &.1& . P. Stapp) A 4uantum Theor! of the #ind$%rain Interface) 1//:
I refer a)ain to Stapp/s criticism of 6delman/s book in 5hapter +.. Stapp uotes 6delman8
The #emem"ered 2resent,
which I ha(e e
/The functionin) of these key Rreciprocal connections Rbetween past (alue&cate)ory connections and current perceptual cate)ori-ations pro(ides the sufficient condition for the appearance of primary consciousness./ p. 9# Stapp )oes on to state8 The uestion arises as to how one is to interpret this claim that this special neural process is a sufficient condition condition for consciousness to occur. oes this claim mean that the occurrence of consciousness is logically entailed by the occurrence of this neural processJ ?t the be)innin) of his book 6delman lists a set of constraints on his undertakin). The first of these is the condition that /any adeuate )lobal theory of brain function must include a scientific theory of consciousness, but to be scientifically acceptable it must a(oid the 5artesian dilemma. In other words, it must be uncompromisin)ly physical and be based on res etensa, and indeed be deri(able from them./ This condition seems to demand that the emer)ence of consciousness be deri'a"le from the properties of matter. 6delman accepts /modern physics as an adeuate description for our purposes of the nature of material properties/. Thus 6delman/s demand appears to be that the emer)ence of consciousness must be actually actua lly deri(able from physics, or at least from properties of systems describable in principle in terms of the concepts of physics. This stron) interpretation is reinforced by the claim made in the final chapter that /no special addition to physics is reuired for the emer)ence of consciousness/. p. 9# If this indeed be the claim then EdelmanAs account falls short . p. 99 The problem with 6delman/s approach is that if one adheres to his demand that the /(iew of brain function and consciousness should be based on materialist metaphysics/, and hence rules out uantum physics, and perforce retreats to classical physics, then there is nothin) in the physics that sin)les out these special processes as bein) in any way special. They are special only because they can be associated in a certain way with thin)s outside classical physics, namely possible conscious e
&.1( . P. Stapp) Mind, Matter, and %uantum Mechanics, 1//&
I )i(e some uotations to illustrate the Stapp&!ames interaction8 0eyond this crucial issue of the efficacy of consciousness, !ames/s principal claim, at the fundamental le(el, is the wholeness, or unity, of each conscious thought. p. ## @ather, consciousness is a comparati(ely simple aspect of the comple< brain process. The a(ailability to us of these )limpses, howe(er flawed and fallible, into the comple< workin)s of the brain pro(ides scientists with insi)hts that can be e
fallible/ and he apparently reco)ni-ed that the problem of the connection of conscious process to brain process was irresol(able within the framework of the classical physics of his day. p. #+
It can be reco)ni-ed that there is then attraction to Stapp about the identity theory in that it should )i(e a uniue uniue insi)ht /into the comple< comple< workin)s of the brain/. The mistake of !ames !ames was to belie(e that this insi)ht insi)ht would be deli(ered deli(ered by introspecti introspection. on. ?lso the present present co)niti(e co)niti(e psycholo)y psycholo)y has been similarly similarly disappointi disappointin). n). 1owe(er, now there are e<uisite scientific in(esti)ations on the brains of cooperatin) human subects, as described in 5hapters 7H' of the present book. The future is illimitable. Stapp apparently makes a reference to this8 5ertain 1eisenber) e(ents that actuali-e lar)e&scale patterns of neuronal acti(ity in human brains will be identified as the physical correlates of human conscious e(ents. p. 9;
Stapp on p. 9+ se(erely critici-es ennett8 aniel ennett/s book Consciousness approaches the problem problem of consciousnes consciousnesss from the materialist materialist Consciousness Eplained approaches point of (iew. 1e announces that /It is one of the main burdens of this work to e
See 5hapters 7H' of the present book.
"eferences to Chapter & 5han)eu<, !. 4. #'% 1euronal 3orkE first published by Fayard, #'%+. 1euronal 3an/ The The iology of 3ind 4antheon, 2ew 3orkE 5rick, F., and Koch, 5. #''; Towards a neurophysiolo)ical theory of consciousness, &eminars in the 1eurosciences 9, 9$+ H9:. 5rick, F., and Koch, 5. #''9 The problem of consciousness, &cientific -merican September #''9, pp. ###&##:. ###&##:. ennett, . 5. #''# Consciousness Eplained ?lien *ane>4en)uin, *ondon. 6ccles, !. 5. #'# 1ypotheses relatin) to the brain&mind problem, 1ature 1!8, +&:. 6ccles, !. 5. #'+ The 1europhysiological asis of 3ind/ The 2rinciples of 1europhysiology 5larendon, A
( 9ew 9ew 0igh 0ightt on the the #ind #ind$% $%ra rain in Prob Proble lem= m= ow ow #ent #ental al ',en ',ents ts Could Influence 9eural ',ents (.1 Introduction
It has lon) been reco)ni-ed that, if non&material mental e(ents, such as the intention to carry out an action, are to ha(e an effecti(e action on neural e(ents in the brain, it has to be at the most subtle and plastic le(el of these e(ents. ?ttention has to be focused on the biolo)ical units of the brain, the neurons or ner(e cells, and on the manner manner of their communicat communication ion at speciali-e speciali-edd sites sites of close contact, contact, the synapses synapses.. ?n introduction introduction to con(en& con(en& tional tional synaptic synaptic theory leads on to an account account of the manner of operation operation of the ultimate synaptic synaptic units. These units are the synaptic boutons that, when e
(.2 4uantum Insights into the #ind$%rain Problem
It is )enerally reco)ni-ed that pro)ress in the understandin) of the mind&brain problem and the nature of consciousness depends on )reat ad(ances in the understandin) of the brain. For e
modular arran)ement of cortical neurons, as dia)rammed by S-entN)othai Fi)ures $.+b and $., lacked the needed )reat amplification in a built&in built&i n desi)n that is described in 5hapter $, the dendron story. (.& The Integrati,e Action of la Impulses on a #otoneuron
? simple introduction to the synaptic concept of brain action is pro(ided by an account of the mode of action of impulses in Ia ner(e fibres on a motoneuron as shown dia)rammatically in Fi)ure 7.la. These lar)e ner(e fibres come from the annulospiral endin)s in a muscle and directly e
Monosynaptic Monosynaptic e
in the 64S4, but this was due to the e
?(era)edd Figure ".2 )#* ?(era)e
recordin)s recordin)s of 64S4s produced by impulses impulses in the same Ia fibre terminatin) terminatin) on si< different different motoneurons motoneurons Mendell and 1enneman 1enneman #':#. )$* ? summary dia)ram of the location of Ia synapses from a sin)le medial )astrocnemius Ia fibre on to a medial )astrocnemius motoneuron at fi(e sites on three different dendrites as indicated 0rown #'%#. )+* Four indi(idual 64S4s selected from a population of %;; responses. )* The a(era)e of all the %;; responses. )e* The component # of the 64S4 deri(ed from fluctuation analysis. )-%h* The components 9, +, and 7 of this same fluctuation analysis. The probabilities of the occurrence of these components are indicated to the ri)ht of each. )i* The reconstructed 64S4 obtained by addin) the wei)hted sum of )e*, )-*, )g*, and )h*8 ;.9'eU;.fU;.#$)U;.;h. !ack et al. #'%#a. )&* ? drawin) of a synapse on a dendrite to show the bouton with (esicles and the synaptic cleft.
for the ran)e in time course of 64S4s produced by a sin)le Ia fibre in Fi)ure 7.9a. An some motoneurons there was clusterin) of its boutons close to the soma, on others more dispersal, and on the second lowermost trace there would be a synaptic clusterin) far out on dendrites.
(. ( The 4uantal 'mission of a %outon ? still more refined le(el of enuiry concerns the 64S4 produced by a sin)le bouton, as indicated in Fi)ure 7. 9, which is a component of the se(eral bouton endin)s of a sin)le Ia fibre Fi)ure 7.9b. 0y a techniue of fluctuation analysis @edman #'%;E 1irst et al. #'%#E !ack et al. #'%#a, #'%#b it has been possible to distin)uish distin)uish between the 64S4s )enerated )enerated by each bouton on a motoneuron when acti(ated by a sin)le Ia impulse. For e
From this remarkable analysis !ack et al. #'%#a there are deri(ed two conclusions on the presynaptic functionin) of a sin)le Ia fibre on a motoneuron8 # There is a wide )radation of intermittency, intermittency, for e
6(idence for uantal fluctuations of unitary I4S4s. # The e
Figure "." ? drawin) of a synapse on a dendritic spine. The bouton contains synaptic (esicles and dense proections of the presynaptic membrane Gray #'%9.
(.* (.* The The Stru Struct ctur ure e of a Chem Chemic ical all! l! Transm ransmitt itting ing S!nap S!napse se in the Centra Centrall 9er,ous S!stem of >ertebrates >ertebrates
? synapse synapse is usually formed by an e
Fi)ure ". The schema of the mammalian central synapse. The acti(e -one ?X is formed by presynaptic dense proections. The postsynaptic a))re)ation of intramembraneous particles is restricted to the area facin) the acti(e -one. S" O synaptic (esiclesE 4? O particle a))re)ations on postsynaptic membrane postsyn. 2ote the synaptic (esicles S" in he
array of synaptic (esicles s( confrontin) the synaptic cleft in a paracrystalline structure. Ather (esicles lie further back, bein) in reser(e. An the ri)ht side, strippin) of the )rid shows the (esicle attachment sites (as to the presynaptic membrane, while in the centre window are seen across the synaptic cleft the particle a))re)ations pa that probably relate to the transmitter receptors on the postsynaptic membrane. An each side of the ner(e terminal there are shown in rectan)ular perspecti(e the presynaptic (esicular )rid and the presynaptic membrane after it has been stripped off. Fi)ures 7.7 and 7. show synapses from the mammalian brain. 6ssentially similar synapses are obser(ed in a (ery different neuronal system, the inhibitory synapses on the Mauthner cell in the fish spinal cord Triller and Korn #'%9. Fi)ure 7. illustrates an important feature, namely that as a rule a synaptic bouton has only one presynaptic (esicular )rid which may co(er only a fraction of the total area of synaptic contact.
Sta)es of synaptic (esicle de(elopment, mo(ement, and e
There are still )reat problems Fi)ure 7.$ in(ol(ed in the ori)in of synaptic (esicles, their char)in) by the specific transmitter molecules, the mo(ement throu)h the bouton for incorporation in the presynaptic (esicular )rid, which we may call the firin) -one Fi)ure 7., and the paracrystalline properties of this )rid whereby of the lar)e number of its constituent synaptic (esicles no more than one is emitted by a ner(e impulse Fi)ures 7. and 7.$b and that only with a probability usually far below one. ?fter this introduction to the fine structure of a bouton we ha(e to consider how it comes about that, from this relati(ely relati(ely lar)e population of synaptic synaptic (esicles on the firin) line of the presynaptic presynaptic (esicular (esicular )rid Fi)ure Fi)ure 7., rarely, if e(er, is more than one dischar)ed by a presynaptic impulse, and usually the probability is ;. or less !ack et al. #'%#aE Korn et al. #'%9E Korn and Faber #'%E @edman and Balmsley #'%+b. I think it has to be proposed that the presynaptic (esicular )rid cf. Fi)ures 7. and 7.$ is a subtle dynamic structure desi)ned to limit the emission of synaptic (esicles by a presynaptic impulse. 0y its unitary operation it sets the probability of (esicular emission from its whole structure and thus from the bouton. It has to be remembered that there are probably no more than 9;;; synaptic (esicles in a bouton, which is adeuate for only a few minutes of normal operation. ?ccordin) to the decon(olution analysis of @edman and associates !ack et al. #'%#aE @edman and Balmsley #'%+b the probability of uantal release may be almost one for some boutons and down to -ero for others, with all ran)es in between. ?ccordin) to the analysis of Korn and associates Korn et al. #'%9E Korn and Faber #'% the mean probability for the different synapses ran)ed from ;.#: to ;.$9. "arious factors modify the probability, the most important bein) the increase due to the 5a9U ion Fi)ure 7.$b, which acts after combination with the
protein calmodulin, four 5a9U ions to one molecule de *oren-o #'%#. Ather factors are the enhancin) effect by a prior stimulus 1irst et al #'%#E #' %#E !ack et al. #'%#b, probably probabl y owin) to the residual 5a9U in the bouton, and by 7& aminopyridine !ack et al. #'%#b and the depressant effect of hi)h&freuency stimulation, hal(in) at about ++ 1Korn and Faber #'%.
espite espite the )eneral )eneral a)reement that the probability probability of release release of a (esicle (esicle uantum of transmitter transmitter from a bouton for a sin)le presynaptic impulse is less than unity, there are minor conflicts between the findin)s of @edman and associates and of Korn and associates. These deri(e from the assumptions used in the decon(olution techniues from the recorded 64S4s. @edman/s )roup !ack et al. #'%#aE @edman and Balmsley Balmsley #'%+b assumes that the 64S4s produced produced by uantal emission from the boutons of an la fibre on a motoneuron are of a standard si-e, the decon(olution on this basis )i(in) the probability of emission for each bouton. bo uton. This analysis yields a bouton number usually usuall y much less than that actually determined by horseradish pero
In conclusion I would su))est that neither decon(olution techniue is fully acceptable. The analysis by @edman and associates leads to a hi)hly improbable solution of bouton number, with many boutons at -ero uantal probability. The solution also reuires that a uantal emission acti(ates all the transmitter sites on the postsynaptic membrane. The solution of Korn and associates is superficially the most attracti(e, because the binomial analysis )i(es results in )ood accord with the number counted in horseradish pero
It is fortunate fortunate that both decon(olution decon(olution techniues techniues deli(er essentially essentially the same information, information, namely that
in response to a single presynaptic impulse a single synoptic "outon is a 8uantal emitter of 'esicles with a pro"a"ility usually well "elow one and ne'er a"o'e one.
This refined story of the uantal operation of synaptic boutons indicates that there should be a ree
There are many materialist theories of the mind, as summari-ed in the four entries of Fi)ure #.9. @adical materialism eliminates itself. The three other materialist theories reco)ni-e the e
4opper then )oes on to )i(e a critical account of all materialistic theories of the mind. Fi)ure #.# )i(es dia)rammatically 4opper/s three&world system. It has been difficult to disco(er statements by philosophers that relate to the precise neural e(ents which are assumed to be identical with mental e(ents. The clearest e
Be can raise the uestion whether there could be e
showin) the Figure 7.: ? dia)ram showin)
pathways pathways concerned in the e
The identity theorist is committed to the doctrine that mental e(ents per se cannot contribute to the )eneration of neural e(ents Fi)ures .9b and .7a, b, which is the doctrine of the closedness of 4orld $. The e
In summary, the mind may be re)arded as a field, in the accepted physical sense of the term. 0ut it is a non& material fieldE its closest analo)ue is perhaps a probability field.
(.5 Summar!
?ttention is concentrated on the mode of operation and the structure of the unitary transmittin) elements of the brain, the synaptic boutons. Intracellular records of the responses of a neuron to an impulse in a sin)le presynaptic fibre ha(e been analysed to re(eal the response e(oked by a sin)le bouton. This has been shown to act in a uantal manner, correspondin) to the emission of a sin)le (esicle of transmitter. 1owe(er, the response is probabilistic, the emission occurrin) with a probability of usually ;. or less and ne(er abo(e #.;. The microstructure of the bouton re(eals that those synaptic (esicles awaitin) e
* Do #ental ',ents Cause 9eural ',ents Analogousl! to the Probabilit! 7ields of 4uantum #echanics? *.1 Introduction
If non&material mental e(ents, such as the intention to carry out an action, are to ha(e an effecti(e action on neural e(ents in the brain, it has to be at the most subtle and plastic le(el of these e(ents, as outlined in 5hapter 7. In the first sta)e of our enuiry an introduction to con(entional synaptic theory leads on to an account of the manner of operation of the ultimate synaptic units. These units are the synaptic boutons that, when e
Similarly the dualist&interactionist hypothesis of 4opper and myself #':: see 5hapter #.7 lacked a precise formulation of the site and manner of the postulated mental&neural interaction. Its appeal lay in its e
In summary, Mar)enau states8 The mind may be re)arded re)arded as a field in the accepted physical physical sense of the term. 0ut it is a nonmaterial nonmaterial fieldE fieldE its closest analo)ue is perhaps a probability field. It cannot be compared with the simpler nonmaterial fields that reuire the presence of matter hydrodynamic flow or acoustic . . . 2or does it necessarily ha(e a definite position in space. ?nd so far as present e(idence )oes it is not an ener)y field in any physical sense, nor is it reuired to contain ener)y in order to account for all known phenomena in which mind interacts with brain. p. ':
1itherto such postulated microsites ha(e had no specific identification, but now the e(idence presented in 5hapters 7.9 and 7.+ su))ests that, because of the probability of (esicular emission, the presynaptic (esicular )rids are ideally fitted to be the tar)ets for the non&material mental e(ents such as the intention to carry out some mo(ement. It is not proposed that the mental e(ents initiate acti(ity at a synapse synapse by an e
7 I #.;$ < #;&9:er) s.
The mass TA of a synaptic (esicle 7; nm in diameter # nm O #; &' m can be calculated to be + < #; &#: ). If the uncertainty uncertainty of the position ?< of the (esicle in the presynaptic presynaptic (esicular (esicular )rid is taken to be # nm, then ', the uncertainty of the (elocity, comes out at +. nm in # ms, which is not far from the ri)ht order of ma)nitude. The presynaptic membrane Fi)ures 7.7 and 7. is about nm across and the time of emission of a (esicle is many tenths of a millisecond Kat- and Miledi #'$. 1owe(er, this calculation assumes that the synaptic (esicle is freely mo(in), which is certainly not the case when it is embedded in the presynaptic (esicular )rid Fi)ure 7.7. Since that )rid is a paracrystalline structure, it could ha(e special resonance resonance relations with a mental mental influence influence operatin) analo)ously analo)ously to a probability field. ? (aluable insi)ht into the manner of operation of the presynaptic (esicular )rid could come from the uantum mechanics of microcrystalline structures. ?s illustrated in Fi)ures 7.7 and 7., the postulated mental influence would do no more than alter the probability of emission of a (esicle already in apposition. It can be concluded that calculations on the basis of the 1eisenber) uncertainty principle show that the probabilistic emission of a (esicle from the presynaptic (esicular )rid could concei(ably be modified by a mental intention actin) analo)ously to a uantal probability field. The second uestion raises the order of ma)nitude of the effect, which is merely a chan)e in probability of emission of a sin)le (esicle Fi)ure 7.. This is many orders of ma)nitude too small for modifyin) the patterns of neuronal acti(ity e(en in small areas of the brain. 1owe(er, there are many thousands of similar boutons on a
pyramidal cell of the cerebral corte<. The hypothesis is that the pro"a"ility field of the mental intention is widely distri"uted not only to the synapses on that neuron "ut also to the synapses of a multitude of other neurons with similar functions of the dendron see 5hapter $. The ne
to the cerebral response to the mental intention to carry out a (oluntary mo(ement.
*.& Amplification of the Postulated Action of a #ental Intention in Changing the Probabilit! of 'mission of a S!naptic >esicle >esicle
Fi)ure .# shows the position of the supplementary motor area SM? of the left cerebral hemisphere in the medial part of the frontal corte< ust anterior to the motor area of the hind limb and e
Figure .1 The left hemisphere from the lateral side with frontal lobe to the left. The medial side of the hemisphere is shown
as if reflected upwards. F. @ol. is the fissure of @olando, or the central fissureE F. Syl(. is the fissure of Syl(ius. The primary motor corte< Ml is shown in the precentral corte< ust anterior to the central sulcus and e
in neuronal acti(ity of the SM? under the influence of a mental intention by the subect. 6(idently the mental intention was brin)in) into action an immense ensemble of neurons, which of course would be essential if it is to cause the desired mo(ement. 0y means of an implanted microelectrode it has been possible to study the responses of sin)le SM? neurons of a monkey while it was carryin) out a (oluntary mo(ement Fi)ure .+a, cE 0rinkman and 4orter #':'. There was an increase in the dischar)e rate of many neurons at about ; ms before the dischar)e of motor cortical neurons that e(entually would cause the willed mo(ement as si)nalled by the electromyo)ram of Fi)ure .+b cf. 6ccles 6ccles #'%9a, #'%9a, b. 6thical consideration considerationss preclude preclude the carryin) carryin) out of such an e
a The mean increase of the t50F \ durin) the motor&seue motor&seuence nce test performed performed with the contralatera contralaterall hand, corrected for diffuse increase of the blood flow. Cross(hatched areas ha(e an increase of r50F si)nificant at the p I ;.;;; le(el. Hatched areas areas ha(e an increase of r50F si)nificant at the p I ;.;; le(el. For other areas shown the r50F increase is si)nificant at the p I ;.; le(el. %eft/ left hemisphere, fi(e subects. #ight/ ri)ht hemisphere, hemisphere, ten subects. subects. b The mean increase of r50F \ durin) internal pro)rammin) of the motor&seuence test8 (alues are corrected for diffuse increase of the blood flow. %eft/ left hemisphere, three subects. #ight/ ri)ht hemisphere, fi(e subects @oland et al. #'%;. Figure .2
-ccording to the dualist(interactionist hypothesis see 5hapters #.7 and 9.9 the presynaptic 'esicular grid pro'ides the chance for the mental intention to change "y choice the pro"a"ility of its synoptic emission. This
would be happenin) o(er the whole ensemble of spine synapses that are acti(ated at that time, probably e(en thousands, since there are about #;;;; on a sin)le cortical pyramidal cell S-entN)othai #':%a. It would be e<& pected that a mental influence analo)ous to a probability field fi eld would e
associated with fle
selection is accomplished accordin) to the learned in'entory of &3- cells for a particular mo'ement. It can be effecti(e only when there is a back)round synaptic barra)e on those cells, because all it can do is to modify the probability of (esicular emission of the acti(ated synapses. Tani Tani and Kurata #'%9 ha(e demonstrated the wide con(er)ence of sensory inputs on to SM? cells. ?ll such acti(ated boutons can be re)arded as presumpti(e sites for modification of the probability of (esicular release by the mental intention. This may seem a clumsy method for initiatin) a mo(ement, but it must be reco)ni-ed that we do ha(e the ability to carry out at will an immense ran)e of mo(ements, and this necessitates a most comple< strate)y of se& lection of SM? neurons from the enormous in(entory of about #;; million pyramidal cells in perhaps +;;;; modules cf. 5hapter $. ?ll we e
Fi)ure .7a illustrates a remarkable findin) of @oland #'%# that, when the human subect was attendin) to a fin)er on which a ust&detectable touch stimulus was to be applied, there was an increase in the r50F o(er the fin)er touch area of the postcentral )yrus of the cerebral corte< as well as in the midprefrontal area. These recording. Thus, increases must ha(e resulted from the mental attention because no touch was applied during the recording.
Fi)ure .7a is a demonstration that the mental act of attention can acti(ate appropriate re)ions of the cerebral corte<. ? similar findin) occurs with attention to the lips in e
Figure Figure ." #
The mean increase of r50F \ durin) pure selecti(e somatosensory attention, that is, somatosensory latent ima)in) without peripheral stimulation. The si-e and location of each focus shown is the )eometrical a(era)e of the indi(idual focus. 6ach indi(idual focus has been transferred to a brain map of standard dimensions with a proportional stereotactic system. The cross(hatched areas ha(e an increase of r50F si)nificant at the p I ;.;;; le(el Student/s t test, one&sided si)nificance le(el. For the other areas shown the r50F increase is si)nificant at the p O ;.; le(el. 6i)ht subects @oland #'%#. $ Mean increases of r50F \ and their a(era)e distribution in the cerebral corte< durin) silent arithmetic with successi(e subtraction of threes from ;. *eft hemisphere, si< subectsE ri)ht hemisphere, fi(e subects. Cross(hatched areas ha(e r50F increases si)nificant at the p I ;.;; le(el. Bith hatched areas p K ;.;# and with outlined areas areas p K ;.; @oland and Friber) #'%.
the silent mental arithmetic of successi(e subtractions of + startin) from ;, there was an increased r50F in a medial strip of the frontal corte< anterior to the SM? and also in other areas of the prefrontal corte< on both sides, as well as in the supramar)inal and an)ular )yri of both parietal lobes. The patterns are more comple< than for the silent thinkin) of a motor mo(ement in Fi)ure .9b. Still more comple< patterns were re(ealed with a memory seuence based on a nonsense word seuence and with the (isual ima)ery of route&findin). In 5hapter #;. there is full reference to the effect of attention on the neocorte
Figure . ?n
information flow dia)ram for mind&brain interaction in the human brain. The three components of Borld 9 outer sense, inner sense, and the e)o, self, or soul are drawn with their communications shown by arrows. ?lso shown are the lines of communication across the interface between Borld Borld # and Borld 9, that is, from the liaison brain to and from these Borld Borld 9 components. components. The liaison brain has the columnar columnar arran)ement arran)ement indicated indicated by the 'ertical "ro7en "ro7en lines. It must be ima)ined ima)ined that the area of the liaison liaison brain is enormous, enormous, with open or acti(e acti(e modules modules numberin) o(er a million, million, not ust the two score depicted here. The supplementary motor area, SM?, is shown specially related to intentions of Borld 9, with the three arrows )i(in) some su))estion of the potential specificity of action of the intention on the modules of the SM?, as discussed in the te
In formulatin) formulatin) more precisely precisely the dualist hypothesis hypothesis of mind&brain mind&brain interaction, interaction, the initial statement statement is that the whole world of mental e(ents Borld 9 has an e
Since it is postulated that mental e(ents can influence only those neural e(ents en)a)ed in the probability of uantal (esicular emission by presynaptic impulses, it would be predicted that the effecti(eness of mental e(ents would be reduced to -ero when the presynaptic back)round was reduced to -ero. *oss of consciousness would occur and would be irre(ersible unless there were re(i(al to a considerable de)ree of the impulse dischar)es in the cerebral corte<. ?n e
(esicular )rid can cause a mental e(ent by a uantum probability wa(e in the re(erse directionJ Such (esicular emissions would occur in immense numbers in the perceptual areas of the cerebral corte<. 1ence there could be an immense summation of /unitary/ mental e(ents in order to surpass the threshold for a perception. ? )eneral obser(ation is that hitherto all hypotheses attemptin) to )i(e some e
and are thou)ht to pro(ide an obecti(e mechanism of conscious awareness. 6delman #':% su))ested that the brain processes sensory si)nals and its own stored information upon this selecti(e base in a phasic cyclic and reentrant manner that is capable of )eneratin) the necessary conditions for conscious co nscious states.
S-entN)othai #':%b su))ested that dynamic patterns offer AsuperstructuresA
and mi)ht be helpful in )i(in) a scientific e
The e
6ccles, !. 5. #'%$ *earnin) in the motor system, 2rog. rain #es. LM, +&#%. 6ccles, !. 5., 6ccles @. M., and *undber), ?. #': Synaptic actions on motoneurones in relation to the two components of the )roup I muscle afferent (olley, J. 2hysiol, %ondon #+$, 9:&7$. 6delman, G. M. #':% Group selection and phasic reentrant si)nallin)8 a theory of hi)her brain function, in The 3indful rain MIT 4ress, 5ambrid)e M?, pp. #&#;;. Fei)l, 1. #'$: The A3entalA and the A2hysicalA Cni(ersity of Minnesota 4ress, Minneapolis M2. Gray, 6. G. #'%9 @ehabilitatin) the dendritic spine, Trends Trends 1eurosci. 1eurosci. , &$. 1assler, @. #':% Interaction of reticular acti(atin) system for (i)ilance and the truncothalamic and pallidal systems for directin) awareness and attention under striatal control, in Cere"ral Correlates of Conscious Eperience, edited by 4. ?. 0user and ?. @ou)eul&0user 6lse(ier&2orth 1olland, ?msterdam, pp. ##; '. 1irst, G. . S., @edman, S. !., and Bon), K. #'%# 4ost&tetanic potentiation and facilitation of synaptic potentials e(oked in cat spinal motoneurones, J. 2hysiol., %ondon +9#, ':&#;'. 1ubbard, !. I. #':; Mechanism of transmitter release, 2rog. 2rog. iophys. 3olec. iol. 9#, ++a. In)(ar, . 1. #'% /Memory of the future./ ?n essay on the temporal or)ani-ation of conscious c onscious awareness, Hum. 1euro"iol. 1euro"iol. 7, #9:&#+$. !ack, !. !. 0., @edman, S. !., and Bon), K. #'%#a The components of synaptic potentials synaptic potentials e(oked in cat spinal motoneurones by impulses in sin)le )roup la afferents, J. 2hysiol., %ondon +9#, $&'$. !ack, !. !. 0., @edman, S. !., and Bon), K. #'%#b Modifications to synaptic transmission at )roup Ia synapses on cat spinal motoneurones by 7&aminopyridine, J. 2hysiol., %ondon %ondon +9#, ### $. Kat-, 0., and Miledi, @. #'$ The measurement of synaptic delay and time course of acetylcholine release at neuromuscular unction, 2roc. #oy. &oc. %ondon #$#, 7%+&7'. Kelly, @. 0., eutsch, !. B., B., 5arlson, S. S., and Ba)ner, Ba)ner, !. ?. #':' 0iochemistry of neurotransmit neurotransmitter ter release, release, -. #e'. 1eurosci. 1eurosci. 5, +''&77$. Korn, 1., Mallet, ?., Triller, ?., and Faber, . S. #'%9 Transmission at a central inhibitory synapse. II. Luantal description of release, with with a physical correlate for binomial n, J. $:'&:;:. :. Korn, Korn, 1., and Faber, Faber, . S. #'% #'% @e)ulat @e)ulation ion and si)nif si)nifica icance nce of probabi probabilis listic tic releas releasee 1europhysiol. 1europhysiol. 7%, $:'&:; mechanisms mechanisms at central central synapses, synapses, in 1ew $nsights into &ynaptic :unction, edited by G. M. 6delman, B. 6. Gall, and B. M. 5owan 2eurosciences @esearch Foundation>Biley, 2ew 3ork, 3ork, pp. :&#;%. Mar)enau, 1. #'%7 The 3iracle 3iracle of Eisten Eistence ce A< 0ow, Boodbrid)e, 5T. Mendell, *. M., and 1enneman, 6. #':# Terminal Terminalss of sin)le sin)le Ia fibers8 fibers8 location, location, density density and distri distribut bution ion withi withinn a pool pool of +;; homo)en homo)eneou eouss motoneu motoneuron rons, s, J. ". 0. #':% ?n or)ani-in) principle for cerebral function8 the unit 1europhysiol. 1europhysiol. +7, #:#&#%:. Mountcastle, ". module and the distributed system, in The 3indful rain M6T 4ress, 5ambrid)e M?, pp. :&;. 4enfield, B., B., and @obert, *. #'' &peech and rain 3echanisms 4rinceton Cni(ersity 4ress, 4rinceton 2!. 4opper, K. @., and 6ccles, 6ccles, !. 5. #':: The &elf &elf and $ts rain rain Sprin)er, 0erlin, 1eidelber). @edman, S. !. #'%; Mechanisms of transmittin) release at Ia afferent terminations, -d'. 2hysiolo. &ci. #, '+&#;;. ?lso in #egulatory #egulatory :unctions :unctions of the C1&. 2rinciples of of 3otion and 0rgan 0rganization, ization, edited by !. S-entN)othai, M. 4alko(its, and !. 1amori 4er)amon, A
A @nitar! !pothesis of #ind$%rain Interaction in the Cerebral Corte .1 Introduction
? lar)e pan of this chapter is de(oted to an attempt to disco(er the anatomical structure of the neocorte< that relates to the self&brain problem. There is firstly the beautiful dia)ram by S-entN)othai #': of the neocorte< with concentration on the pyramidal cell structure Fi)ures $. and :.la. The important de(elopment was pro(ided by the ele)ant studies by Fleischhauer of 0onn and 4eters of 0oston and their pupils. The bundlin) of the apical dendrites dendrites of pyramidal cells as they ascend to lamina I was re(ealed re(ealed by precise precise histolo)ical histolo)ical studies
with microphoto)r microphoto)raphs aphs Fi)ures $.$&$.: $.$&$.: and is illustrate illustratedd in the drawin)s drawin)s of Fi)ures Fi)ures $.%, $.#;, and %.9b. The bundles of dendrites are called dendrons dendrons and there are about #;; apical dendrites dendrites in each dendron. The detailed structure of a spine synapse is illustrated in Fi)ure :.#b. There are o(er #;; ;;; spine synapses on the bundled apical dendrites of a dendron, which is thus an enormous recei(in) structure for e
It should be reco)ni-ed that there has been a philosophical re(olution since the days of @yle #'7' and the beha(iourists, who denied any scientific meanin) to the philosophical concepts of consciousness and to the e
Figure !.1 ?n
information flow dia)ram for brain&mind interaction. The three components of Borld 9Houter sense, inner sense, sense, and the psyche, or selfHare selfHare shown with their connecti(ities. connecti(ities. ?lso ?lso shown by reciproc reciprocal al arrows are the lines of communication across the interface between Borld # and Borld 9, i.e. from the liaison brain to and from these Borld 9 components. The liaison brain has the columnar arran)ement a rran)ement of its dendrons, which number about forty million.
and termination of the reciprocal arrows, which si)nify the interaction across the interface between the two Borlds. Borlds. This dia)ram will de(elop more meanin) later in the book. .& The 9euronal Composition of the Cerebral Corte
In Fi)ure $.9 the left cerebral hemisphere is shown in position in the head with some functional areas defined. The essential essential component is the cere"ral corte, which is a cellular cellular layer about + mm thick co(erin) the whole corte< e(en in its deep foldin)s so that it has an area of about 9 ;; cm 9 for both hemispheres. The cerebral corte< is created by densely packed ner(e cells with their associated ner(e fibres, there bein) about 7; ;;; mm &9, which would )i(e a total of ten thousand million for the whole corte<. Fi)ure $.+a illustrates some ner(e cells, which were selected from the tan)led mass of a Gol)i stainin) and drawn by the )reat Spanish neuroanatomist @amn y 5aal. Af special importance are the pyramidal cells 6, , 5, 0, each with its apical dendrite ascendin) towards the surface and its a
Figure !.2 The
motor and sensory transmittin) areas of the cerebral corte<. The appro
to lea(e the corte<. ?t least $;\ of cortical cells are pyramidal cells. Fi)ure $.+b shows three pyramidal cells, one in lamina " and two deep in lamina III. The most important features of pyramidal cells are the small protuberances or spines that can already be seen in the dendrites dendrites in Fi)ure Fi)ure $.+a but are more defined in Fi)ure $.+b, where they are seen to be in(ol(ed in close contacts contacts with ner(e fibres, makin) the spine synapses, synapses, which are the principal prin cipal means of communicat communication ion between ner(e cells in the corte<. ? wide (ariety of spine synapses is drawn in Fi)ure $.7a on a pyramidal pyramidal cell of a special part of the cerebral corte<, the hippocampus. Finally Fi)ure $.7b shows an apical dendrite from the mouse (isual corte< thickly encrusted by spines which can be counted, there bein) about one per micrometre and
connec tions. # 6i)ht neurons from a Gol)i preparation of the three superficial layers Figure !.3 2eurons and their synaptic connections.
of frontal corte< from a month&old child. Small 0, 5 and medium , 6 pyramidal cells are shown with their profuse dendrites co(ered with spines. ?lso shown are three other cells ?, F, K, which are in the )eneral cate)ory of Gol)i type II with their locali-ed a
hence at least ;;; for each lamina " apical dendrite with its side branches and tufted endin) Fi)ure %.9. In Fi)ure $. is illustrated the uni(ersally accepted si< laminae of the cerebral corte< with two lar)e pyramidal cells in lamina ", three in lamina III, and one labelled &p+ in lamina II. There are many other pyramidal cells shown in shadowy outline and also se(eral non&pyramidal cells, particularly in lamina I". It will be noted that the pyramidal apical apical dendrites finish in a tuft&like branchin) in lamina I.
Figure !." # ? drawin) of a hippocampal
pyramidal cell to illustrate the di(ersity of synaptic endin)s on the different -ones of the apical and basal dendrites and the inhibitory synaptic endin)s on the soma 1amlyn #'$+. $ Mosaic micro)raphs of an apical dendrite of a pyramidal cell in the mouse area a rea striata "al(erde "al(erde #'$%.
.( The %asic "ecepti,e @nit of the Cerebral Corte= The Dendron
espite the intense microscopic study of the cerebral corte<, the basic neuronal assembly was not appreciated until Fleischhauer Fleischhauer et al. #':9 and Feldman and 4eters #':7 reco)ni-ed the tendency of the pyra& midal apical dendrites to assemble to)ether in small bundles or clusters on their route to lamina #. Since that time they and their associates ha(e con(incin)ly demonstrated this (ertical assembla)e of apical dendrites from
Figure !. ? three&dimensional construct showin) cortical neurons of (arious types. There are two pyramidal cells in lamina
" and three in lamina III, one bein) shown in detail in a column to the ri)ht S-entN)othai #':.
pyramidal cells in lamina " that were oined in more superficial laminae by the apical dendrites of pyramidal III and II cells Schmolke and Fleischhauer #'%7E Feldman #'%7E Schmolke #'%:E 4eters and Kara #'%:. In the photomicro)raph of Fi)ure $.$a a Gol)i stainin) of the rat (isual corte< re(eals lar)e and medium pyramidal cells of lamina ", si< bein) labelled8 l abelled8 #, 9 lar)e l ar)e and +, 7, , $ medium. 6ach apical dendrite ascends directly throu)h the laminae. The bundles or clusters are not well reco)ni-ed in Fi)ure $.$a because only a fraction of the pyramidal cells is stained by the Gol)i method. 1owe(er, the apical dendrites of pyramidal cells #, 9, and + can be seen in close apposition. In the trans(erse section of Fi)ure $.$b at the le(el of the broken line in lamina I" of Fi)ure $.$a, there are many )roups of trans(ersely sectioned dendrites. In a similar preparation Fi)ure $.:a many discrete clusters can be seen, one bein) indicated by the three open arrows. Fi)ure $.:b shows an electron microscopic 6M picture of a trans(ersely sectioned apical dendrite with the ori)ins of three spines, the most prominent bein) labelled with an arrow and S. Fi)ures $.$&$.% enable the (isuali-ation of the bundles or clusters of apical dendrites. It is most clearly shown in trans(erse sections in lamina I" Fi)ures $.$b and $.:a before there is the lar)e addition from laminae III and II pyramidal cells 4eters and Kara #'%:. ?s a conseuence of this lar)e accretion to the bundle there may be partial partial confluenc confluencee of bundles in lamina II. The perspecti( perspecti(ee drawin) drawin) Fi)ure $.% by Schmolke Schmolke #'%: )i(es an e
There are many small pyramidal cells in laminae I" and "I, but their apical dendrites ha(e a uite different course, ascendin) only up to lamina III before tuftin). They do not oin the bundles. Thus about one half of the neurons of the cerebral corte< do not participate in the bundles or clusters. espite this partial disarray there is a)reement by 4eters and Fleischhauer and their associates that the apical bundles or clusters dia)rammatically shown in Fi)ures $.% and %.9 are the basic anatomical units of the cerebral corte< Schmolke and Fleischhauer #'%7E 4eters and Kara #'%:. They are obser(ed in all areas of the corte< that ha(e been in(esti)ated and in all mammals includin) humans. 1itherto there has been no satisfactory su))estion of the functional role of these anatomical units. It is now proposed that they are the cortical units for reception, which would )i(e them a preeminent roleE hence it is desirable to name them. Since they are composed essentially of dendrites, the name dendron is proposed. In the nineteenth century, dendron was an alternati(e term for dendrites, but it has fallen into disuse in this century. For e
Figure !.! # ? Gol)i preparation of the rat (isual corte< area #: in a (ertical section throu)h laminae II&"I to show apical dendrites of lamina " pyramidal cells proectin) throu)h laminae I", III, and II. $ ? tan)ential section of lamina I" at the le(el indicated indicated by the "ro7en "ro7en line in a. The arran)ement of the apical dendrites )small open circles+ in clusters can be well
seen 4eters and Kara #'%:.
after #';; it was not used by @amn y 5aal or by Sherrin)ton. ?s the proposal is that the dendron is a fundamental neural unit of the cerebral corte<, the endin) of /on/ appropriately links it with the units of physics. ?ppro
a ?pical dendritic clusters as (isuali-ed in a tan)entially oriented section at the le(el of layer " of rat (isual corte<. Ane cluster is indicated by open arrows. Cali"ration line/ 9 m. b The lar)e profile is a trans(ersely sectioned apical dendrite within a dendritic cluster, as (isuali-ed in a tan)ential section throu)h layer I" of rat (isual corte<. ?t S, a dendritic spine e
dendrite with its lateral branches Fi)ure :.9a and its terminal tuft, but more usually it would be under 9;;;. If there are :;&#;; apical dendrites in a dendron, the total number of spine synapses would be o(er #;;;;;. In addition to the apical dendrite there are also numerous synaptic inputs to
? stereoscopic dia)ram of a portion of rabbit (isual corte< comprisin) laminae II&III, lamina I", and the upper half of lamina ". The distribution of dendrites )white+, myelinated a
Figure !.8
the basal dendrites and soma, as partly indicated in Fi)ure $.+b, but these are mostly inhibitory. The synaptic output of a dendron is enormous. The a
Figure !.9 #
The )eneral principle of cortico&cortical connecti(ity shown dia)ramatically in a non&con(oluted brain. The connections are established in hi)hly specific patterns between (ertical columns with a diameter of 9;;&+;; m in both
hemispheresE T1 O thalamus. $ ? Gol)i&stained branchin) of a sin)le cortico&cortical afferent, oriented in relation to the module with a sin)le afferent in a, but at se(eral times hi)her ma)nification. S-entN)othai #':%. &cale "ar. #;; m.
.* #ental Influences on the %rain Bhen one is at absolute rest in a darkened silent room, it is possible to en)a)e in some specific thinkin). For e
?s ori)inally e
4rofessor Garrido has drawn my attention to the fact that M. 0un)e has used the word /psychon/ in his book The 3ind(ody 2ro"lem 2ro"lem 4er)amon, #'%;. Its deri(ation is described on pa)e +:. 1owe(er, it is a mistake to deri(e the word /psychon/ from the Greek word NOPQR9 /soul/ /soul/ or /spirit/H )0ford )0ford English Dictionary+ for e(ery plastic neural system 0un)e #'%;, p. $, which is a purely materialist concept. Bhat 0un)e needs is a word deri(ed from the Greek word SUVWXYZ[, /that may be moulded/, which would be /plaston/. So 0un)e should substitute /plaston/ for /psychon/ and lea(e /psychon/ for the purely mental usa)e proposed here.
mental intensity from -ero to a ma
rawin)s of three dendrons showin) the manner in which the apical dendrites of lar)e and medium pyramidal cells bunch to)ether in lamina I" and more superficially, so formin) a neural unit. ? small proportion of apical dendrites do not oin the bundles. The apical dendrites are shown terminatin) in lamina I. This termination is in tufts that are not shown. The other feature of the dia)ram is the superpositi superposition on on each neural unit or dendron of a mental unit or psychon that has a characteris characteristic tic markin) markin) )solid s8uares, open s8uares, solid circles+. 6ach dendron is linked with a psychon )i(in) its own characteristic unitary e
the comple
? drawin) drawin) of the postulated postulated patterned arran)ement arran)ement of dendrons dendrons as seen from the cortical cortical surface. They ha(e a(era)e a(era)e diameter and spacin) cf. Fi)ure Fi)ure $.#;. $.#;. 5entral on each dendron is the symbol symbol of its psychon8 psychon8 solid s8uares, open s8uares, s8uares, and circles. 2ote the scale of 9 mm. Figure !.11
because Borld Borld 9 is drawn abo(e the Borld Borld # of the brain. This was for dia)rammatic con(enience. The reciprocal arrows across the interface show that all the Borld 9 action is in the neocorte<. This proposed unitary linka)e between psychons and dendrons Fi)ure $.#; leads to many theoretical de(elopments that in turn will lead to the de(elopment of e
Fi)ure .7 shows that the mental e(ents of thinkin) psychons can (ery effecti(ely acti(ate the neocorte< e(en when no bodily mo(ement is induced. To analyse this action it is essential to define the mode of action of a dendron Fi)ures $.% and %.9 with lar)e ensembles of apical dendrites of pyramidal cells, each with about one spine synapse per micrometre Fi)ure $.7b, so that there can be #;;;;; spine synapses on a dendron. The apical dendrites of a dendron are usually closely associated, but not touchin) Fi)ure $.7b, althou)h their spines Fi)ure $.7a may interlace Feldman #'%7.
? drawin) drawin) of a synapse on a dendritic spine. The bouton contains synaptic (esicles and dense proections on the presynaptic membrane Gray #'%9.
Figure !.12
Fi)ure $.#9 )i(es a dia)ram of a spine synapse, showin) the ner(e fibre e
Figure Figure !.13 # The schema of the mammalian central synapse. The acti(e -one ?X is formed by presynaptic dense proections spacin) synaptic (esicles S". 4? O particle a))re)ations of postsynaptic membrane postsyn.. 2ote the synaptic (esicles in he
Further structural analysis, particularly by the free-e&fracture techniue of ?kert et al. #':, has led to the construction of a dia)ram of an ideali-ed spine synapse Fi)ure $.#+a, which is shown in perspecti(e with partial e
There are only appro
The materialist critics ar)ue that insuperable difficulties are encountered by the hypothesis that immaterial mental e(ents such as thinkin) can act in any way on material structures such as neurons of the cerebral corte<, as is depicted in Fi)ure $.#. Such a presumed action is alle)ed to be incompatible with the conser(ation laws of physics, in particular with the first fi rst law of thermodynamics. This obection would certainly be sustained by the nineteenth¢ury physicists and by neuroscientists and philosophers who are still ideolo)ically in the physics of the nineteenth century, not reco)ni-in) the re(olution wrou)ht by uantum physicists in the twentieth century. In formulatin) more precisely the dualist hypothesis of mind&brain interaction, the initial statement is that the whole world of mental e(ents Borld 9 has an e
1itherto, for the whole of perceptual e
5
0ack)round acti(ation by attention to the tactual area Fi)ure .7. Sensory input into the tactual ner(ous system. ?cti(ation in the neocorte< of the dendrons of the tactual system. Increased e
?ll other perceptions of the outer sense in Fi)ure $.# can be similarly e
?n e
si)nal of the psychon would carry into Borld 9 the special e
It should be reco)ni-ed that there is superb desi)n of the t he dendrons for their recepti(e function, both neuronal and psychic. It must be accepted that all mammals are conscious bein)s with some control of their actions and some conscious eMIT 4ress, 5ambrid)e M?. 6ccles, !. 5. #'%$ o mental e(ents cause neural e(ents analo)ously to the probability fields of uantum mechanicsJ, 2roc. 2roc. #oy. &oc. %ondon %ondon 0 99:, 7##&79%. 6ccles, !. 5. #'%' E'olution of of the rain/ Creatio Creation n of the &elf @outled)e, *ondon. Fei)l, 1. #'$: The A3entalA and the A2hysicalA Cni(ersity of Minnesota 4ress, Minneapolis. Feldman, M. #'%7 Morpholo)y of the neocortical pyramidal neuron, in Cere"ral Corte. "ol. #. Cellular Components of 3ork, pp. #9+&9;;. the Cere"ral Corte, edited by ?. 4eters and 6. G. !ones 4lenum, 2ew 3ork, Feldman, M., and 4eters, ?. #':7 ? study of barrels and pyramidal dendritic clusters in the cerebral corte<, rain #es. ::, &:$. Fleischhauer, K., 4etsche, 1., and Bittkowski, B. #':9 "ertical bundles of dendrites in the neocorte<, \. -nat. Entwic7l. Gesch. #+$, 9#+&99+. Goldman, 4. S., and 2auta, B. !. 1. #':: 5olumnar distribution of corticocortical fibers in the frontal association, limbic and motor corte< of the de(elopin) rhesus monkey, rain #es. #99, +'+&7#+. Gray, 6. G. #'%9 @ehabilitatin) the dendritic spine, Trends 1eurosci. , &$. 1amlyn, *. 1. #'$+ ?n electron microscope study of pyramidal neurons in the ?mmon/s 1orn of the rabbit, J. -nat. ':, #%'&9;#. 1ebb, . A. #'%; -n Essay on 3ind *awrence 6rlbaum, 1illsdale. !ack, !. !. 0., @edman, S. !., and Bon), K. #'%# The components of synaptic potentials e(oked in cat spinal motoneurones by impulses in sin)le )roup Ia afferents, J. 2hysioi, %ondon %ondon +9#, $&'$. Kelly, @. 0., eutsch, !. B., 5arlson, S. S., and Ba)ner, !. ?. #':' 0iochemistry of neurotransmitter release, -. #e'. 1eurosci., 1eurosci., 5, +''&77$.
Korn, 1., and Faber, . S. #'%: @e)ulation and si)nificance of probabilistic release mechanisms and central synapses, in 1ew $nsights into &ynaptic :unction, edited by G. M. 6delman, B. 6. Gall, and B. M. 5owan 2eurosciences @esearch Foundation Biley, 2ew 3ork, pp. :&#;%. Mar)enau, 1. #'%7 The 3iracle of Eistence A< 0ow, Boodbrid)e 5T. 4eters, ?., and Kara, . ?. #'%: The neuronal composition of area #: of rat (isual corte<. I". The The or)ani-ation of pyramidal cells, J. Comp. 1eural. 1eural. 9$;, :+&';. 4opper, K. @., and 6ccles, !. 5., #':: The &elf and $ts rain Sprin)er, 0erlin, 1eidelber). @amn y 5aal, S. @. #'## Histologie du du &yst]me 1er'eu 1er'eu de $AHomme et des des
; The ',olution of Consciousness ;.1 Introduction For consciousness to be e
Mammals ha(e a cerebral corte< ualitati(ely similar to ours, thou)h, with rare e
I am presentin) a biolo)ical basis for an e(olutionary ori)in of consciousness. It deri(es from a hypothesis of mind&brain interaction that has already been published 6ccles #'';a, b and 5hapters and $ and that is based on the special anatomical anatomical and functional properties of the mammalian cerebral corte<. The microproperties microproperties of neural communication in the cerebral corte< Fi)ure :.la are in classical physics and are not of immediate concern in mind&brain interaction. @ather, our concern is in the ultramicroproperties Fi)ure :.9b, where uantum physics may be e
Figure Figure .1 #
? three&dimensional construct by S-entN)othai showin) cortical neurons of (arious types. There are two pyramidal cells in lamina " and three in lamina III, with one shown in detail on the ri)ht S-ent N)othai #':%. $ The detailed structure of a spine synapse on a dendrite den, st O a
:.9 # ? drawin) of a lamina " pyramidal cell 4yr, with its apical dendrite showin) the side branches and the terminal tuft all studded with spine synapses and boutons not all shown. The soma with its basal dendrites has an a
In)(ar #''; and @oland et al. @oland, *arsen, *assen, Skinh; #'%; Fi)ure .9, or by the more accurate positron&emission tomo)raphy 46T scannin) techniue of @aichle and associates 4osner, 4etersen, Fo<, and @aichle #'%%5hapter #;. for the acti(ity of the human brain in response, for e
The apical dendrites of the pyramidal cells in laminae ", III, and II bundle to)ether as they ascend to lamina I Schmolke and Fleischhauer #'%7E 4eters and Kara #'%: Fi)ures $.% and %.9, so neural receptor units of the cerebral corte< are formed, bein) composed of appro
;.( Cerebral ',olution and Consciousness= C onsciousness= The !pothesis
In all mammals so far e
Figure :.+ a The brain of an insecti(ore neocorte< abo(e
the prepyriform corte<. b ? trans(erse section of the brain of an insecti(ore a hed)eho), c ? dia)ram of the trans(erse section shown in b showin) the followin)8 55 O corpus c orpus callosumE I?G O dia)onal band of 0rocaE F O fimbria&forni< comple
2ow comes the uestion about the reptilian ori)in of mammals !erison #'';E Clinski #'';. The forebrain of reptiles Fi)ure :.7 shows an unde(eloped unde(eloped cerebral corte<, which is in )reat contrast contrast to the most primiti(e primiti(e mammalian corte< Fi)ure :.+. 5learly, the reptilian cerebral corte< has far to e(ol(e before it can play a si)nificant role in cerebral acti(ity and in mind&brain interaction based on dendrons. 0ut we ha(e to reco)ni-e that the primiti(e reptilian cerebral corte< Fi)ure :.7 did, e(entually, e(ol(e into a primiti(e mammalian corte< Fi)ure :.+. There seems to be no )ood e(idence e(idence that reptiles e
:.7 ? 2issl section from the encephalon of the alli)ator -lligator mississippiensis. The corte< is di(ided into the medial corte< M, dorsomedial corte< M, dorsal corte< , and lateral corte< *. ?"@ O anterior dorsal (entricular rid)eE S O septumE ST@ O striatum Clinski #'';.
Figure
So consciousness appears to ha(e come into the mindless world of biolo)ical e(olution with the ori)in of mammals. ?nimals would not e
Figure . 5omponents
of the cerebral hemispheres of a pi)eon. The basic anatomy of the telencephalon of birds is illustrated by a series of trans(erse sections throu)h the ri)ht cerebral hemisphere. The planes of the sections are illustrated in the inset )upper left+, which shows a lateral (iew of a pi)eon brain. ?55 O nucleus accumbensE 0?S O nucleus basalisE M* O dorsomedial lateral nucleiE 6 O ectostriatumE 1? O hyperstriatum accessoriumE 1IS O hyperstriatum intercalates superiorisE
1" O hyperstriat hyperstriatum um (entraleE I24 O intrapeduncul intrapeduncular ar nucleusE * O field *E *FM O frontal medullary laminaE *1 O lamina lamina hyperstriatica.
The special structure the Bulst includes the (arious components 1?, 1IS, 1", and *1 of the hyperstriatum shown in Fi)ure :. and is specially related to the (isual brain. It is the most rostral telencephalon. ?lthou)h there is indication that the Bulst is the most ad(anced component of the a(ian brain, much more detailed information is reuired before one can relate the Bulst to the presumed a(ian consciousness. 6(en the most e(ol(ed brains of molluscs, i.e. the octopus or aplysia, ha(e far too simple a brain to pro(ide conscious e
It should be pointed out that the present hypothesis of the e(olutionary ori)in of consciousness has four )reat attractions8 i that it is neuroanatomical, ii that it is in accord with biolo)ical e(olution, iii that it utili-es the most hi)hly e(ol(ed structures of the cerebral corte< with their ultramicrosite operation, and i( that it is based on uantum physics. The uantum physicist Stapp #''+ see 5hapters +.#+ and +.#7 has maintained that classical physics pro(ides an unacceptable basis for the hypotheses of brain&mind interaction, which instead reuires uantum physics. So Stapp #''9 reects such theories as the neuronal network Mountcastle #':% and neuronal )roup selection 6delman #'%' and proposes a theory based on uantum physics. This theory needs a secure basis in ultramicrosite neuroscience of the cerebral corte< where uantum physics could be effecti(e. This has now been done by 0eck and myself 0eck and 6ccles #''9 and 5hapter '. There has recently been much attention )i(en to the neuronal mechanisms that cause interactions between widely separated cortical areasE this has been named the bindin) problem 5rick and Koch #'';E amasio #'%'E Sin)er, ?rtola, 6n)el, and Kreiter #''#. It is here su))ested that )lobal conscious e
"eferences to Chapter ; ?kert, K., 4eper, K., and Sandri, 5. #': in Cholinergic 3echanisms, edited by 4. G. Baser @a(en, 2ew 3ork, pp. 7+&:.
?rmstron), . M. #'%# The 1ature of 3ind 5ornell Cni(ersity 4ress, Ithaca 23. 0eck, F., and 6ccles, !. 5. #''9 1ature submitted. 5rick, K, and Koch, 5. #''; &eminars in the 1eurosciences 5, 9$+&9:. amasio, ?. @. #'%' 1eural Computat. Computat. #, #9+&#+9. ennett, . 5. #':% rainstorms MIT 4ress, 5ambrid)e M?, p. ++. 6ccles, !. 5. #'%$ 2roc. 2roc. #oy. &oc. &oc. %ondon 97;, 7++&7#. 6ccles, !. 5. #'';a in The 2rinciples of Design and 0peration 0peration of the rain, edited by !. 5. 6ccles and A. 5reut-feldt 6
5 The ',olution of Compleit! of the %rain with the 'mergence 'mergence of Consciousness 5.1 Introduction
5hapters $ and : describe a considerable ad(ance in understandin) the microsites of the neocorte< with the manner in which consciousness is e
possibly also birds, but not in(ertebrates and lower l ower (ertebrates such as fish and e(en amphibia and reptiles that ha(e instinctual and learned responses. 1owe(er, much more e
In this enuiry we come to the mammalian neocorte<, which is ualitati(ely similar to ours, thou)h usually much smaller. It has the same neuronal structure as illustrated in Fi)ures $.+a, b and %.la, which show the most numerous and important neurons, the pyramidal cells 0, 5, , 6 in Fi)ures $.+a, b and %.laE three in Fi)ure $.+b and fi(e in Fi)ure %.la are drawn with many in shadowy outline. The corte< has si< layers Fi)ure %.la and all true pyramidal cells are in laminae ", III, II, each with an apical dendrite and many side branches proectin) towards the surface to end as a terminal tuft. ? pyramidal cell has a ner(e fibre or a
Figur Figuree 8.1 # ? three&dimensional construct by S-entN)othai #':' showin) cortical neurons of (arious types. There are two pyramidal cells in lamina " and three in lamina III. one bein) shown in detail in a column to the ri)ht, and two in lamina II. $ The detailed structure of a spine synapse on a dendrite den. t8 st O a
Figure 8.2 # ? drawin) of a lamina " pyramidal cell with its apical
dendrite showin) the side branches and the terminal tuft all studded with spine synapses not all shown. The soma with its basal dendrites has an a
2er(e impulses are brief si)nals of about one millisecond depolari-ation passin) alon) ner(e fibres to finish in the terminal bouton as in Fi)ure %.#b and as )reatly enlar)ed in Fi)ures %.+ and %.7. Transmission across a synapse occurs when an impulse in(adin) the bouton causes a synaptic
Figu Figure re 8.3 The schema of a ner(e terminal bouton of a mammalian central synapse showin) the acti(e -one, the presynaptic (esicular )rid with a )eometrical desi)n of dense proections ?X in trian)ular array and of synaptic (esicles S" in he
(esicle to dischar)e its contents of transmitter substance into the synaptic cleft, as indicated by the cur(ed arrow in Fi)ure %.+, and so to act on the specific receptor sites across the synapse e in Fi)ure %.#b and postsyn. in Fi)ure %.+. For e
?n a
Figure Figure 8."
This is the con(entional macrooperation of a pyramidal cell of the neocorte<, and it can be satisfactorily described by classical physics and neuroscience, e(en in the most comple< desi)n of network theory and neuronal )roup selection S-entN)othai #':%E Mountcastle #':%E 6delman #'%'E 5han)eu< #'%. It may seem that this )enerally accepted simplified account of the neuronal mechanism of the neocorte< already indicates a hi)h le(el of comple
5.& 3rganiation of the 9eocorte
There is a)reement by 4eters and Kara #'%: of 0oston and Fleischhauer and Schmolke of 0onn #'%7 that the apical dendrites of the pyramidal cells in laminae ", III, and II Fi)ure %.la bundle to)ether as they ascend to lamina I Fi)ures $.%, $.#;, and %.9b. So they are neural receptor units of the cerebral corte< composed of about #;; apical dendrites plus their branches Fi)ure %.9b that are to)ether called a dendron. The enormous synaptic input into the :;&#;; apical dendrites bundled into a dendron Fi)ure %.9b can be calculated to be much more than #;;;;; synapses, if there are on the a(era)e about 9;;; on each apical dendrite Fi)ure %.9a. 5.( The @ltrastructure of S!napses
In Fi)ure %.#b there is a )eneral drawin) of a cortical synapse, but it is now necessary to describe the ultrastructure as re(ealed to ?kert and associates usin) the techniues of free-e fracture, electron microscopy, and selecti(e stainin). It is here that we enter into a hi)her le(el of comple
? ner(e impulse propa)atin) into a bouton causes a lar)e influ< of 5a 9U ions Fi)ure %.b. The input of four 5a 9U ions acti(ates a synaptic (esicle (ia calmodulin and may cause it momentarily to open a channel Fi)ure %.b throu)h the contactin) presynaptic membrane, as indicated by the cur(ed arrow in Fi)ure %.+, so that its total transmitter content is liberated into the synaptic cleft in a process called eocytosis.
?t most a ner(e impulse e(okes a sin)le e
Sta)es of synaptic (esicle de(elopment, mo(ement, and e
Figure Figure 8.
presented by the back)round noise that was e(en as lar)e as the si)nals bein) studied Fi)ure %.$. Fortunately the si)nal can be repeated many thousands of times for effecti(e a(era)in) abo(e the back)round noise, and special statistical procedures of decon(olution analysis ha(e been de(ised to e
5. The Probabilit! of 'oc!tosis
Fi)ure Fi)ure %.$ shows dia)rammatically dia)rammatically the e
#'';. Moreo(er, the statistical techniue of decon(olution analysis enables the determination of the probability of release by a ner(e impulse of a sin)le synaptic (esicle, an e
Figure 8.! a&d The e
as described in the te
5.; Ps!chons
The hypothesis that the dendron is the neural unit of the neocorte< leads on to the attempt to disco(er the complementary mental units which interact with the dendron, for e
The hypothesis has been proposed 6ccles #''; and 5hapter $ that all mental e(ents and e
Figure %.:
? drawin) of three dendrons showin) the manner in which the apical dendrites of lar)e and medium pyramidal cells bunch to)ether in lamina I" and more superficially, so formin) a neural unit. ? small proportion of apical dendrites do not oin the bunches. The apical dendrites are shown terminatin) in lamina I. This termination is in tufts that are not shown. The other feature of the dia)ram is the superposition on each neural unit, or dendron, of a mental unit, or psychon, that has a characteris characteristic tic markin) markin) )solid s8uares, open s8uares, solid circles+. 6ach dendron is linked with a psychon )i(in) its own characteristic unitary e
at all le(els of intensity. 6ach of these mental units is reciprocally linked in some unitary manner to a dendron, as is illustrated ideally in Fi)ure %.: for three dendrons. The three associated mental units are represented as an ensheathin) of the three dendrons by desi)ns of solid suares, open suares, and solid circles. ?ppropriately we name these proposed mental units /psychons/. ?ccordin) to the unitary hypothesis 6ccles #''; and 5hapter $ there is a uniue linka)e of each psychon with its dendron in brain&mind interaction, for e
There has been a lon) history history concernin) concernin) the manner in which (oluntary (oluntary mo(ements can be )enerated )enerated.. Some neuroscientists, takin) up a materialistic do)ma, deny that the non&material mind can effecti(ely influence the brain so as to cause an intended mo(ement. This materialistic do)ma ne)lects the conscious performance which we e
hemisphere Figure 8.8 The left hemisphere
from the lateral side with the frontal frontal lobe to the left. The medial side of the hemisphere hemisphere is shown as if reflected upwards. F. @ol. is the fissure of @olando, or the central fissureE F. Syl(. is the fissure of Syl(ius. The primary motor corte<, Ml, is shown in the precentral corte< c orte< ust anterior to the central sulcus and an d e
In)(ar #''; introduced the term pure ideation, which is defined as co)niti(e e(ents that are unrelated to any on&)oin) sensory stimulation or motor performances. 1e stated that a study of brain structure acti(ated by pure ideation therefore appears to open up a new approach to understand the human psyche.
In)(ar and his associates at *und #'$ onwards introduced the study of the re)ional cerebral blood flow r50F to display by cerebral ideo)raphy the acti(ity of the brain in pure ideation in all the immense (ariety )enerated by the psyche. 0y radio&
a(era)e (alue of # in +, it would ha(e almost doubled the 64S4s for the whole dendron. Thus there would be an effecti'e mind("rain action without infrin)in) the conser(ation laws 0eck and 6ccles #''9 and 5hapter '. The (ery low probabilities of uantal release in the corte< )i(e e
0efore the e(olution of the mammalian brain, it has been proposed in a recent publication 6ccles #''9 and 5hapter :, the animal world was literally mindless, without feelin)s. In the e(olution of e(en the most primiti(e mammals, the basal insecti(ores, there came to e
It has been further hypothesi-ed that each psychon is linked in a unitary manner to a specific dendron, which is the basis of mind&brain interaction. Luantum physics )i(es a new understandin) of the mode of operation of the presynaptic (esicular )rid and of the probability of eBiley, Foundation>Biley, 2ew 3ork, 3ork, pp. :&#;%. *ibet, *ibet, 0. #''; 5erebral 5erebral processes that distin)uish distin)uish conscious e5?# neurons in the hippocampal slice, J. 1eurosci. 1eurosci. 1/, 2o. +, $9$&$+$. Schmolke, 5., and Fleischhauer, K. #'%7 Morpholo)ical characteristics of neocortical laminae when studied in tan)ential semi&thin sections throu)h the (isual corte< in the rabbit, -nat. Em"ryol. Em"ryol. 1!9, #9&#+9. Stapp, 1. 4. #''# 0rain&mind connection, :ound. 2hys., 2hys., 21, 2o. #9.
Stapp, 1. 4. #''9 in 1ature, 1ature, Cognition and and &ystem, edited by M. 5ar(allo Kluwer, ordrecht. S-entN)othai, !. #':% The neuron network of the cerebral corte<8 a functional interpretation, 2roc. #oy. #oy. &oc. %ondon 9;#, pp. 9#'&97%. S-entN)othai, !. #':' *ocal neuron circuits of the neocorte<, in The 1eurosciences :ourth &tudy 2rogram, edited by F. A. Schmitt and F. G. Borden Borden MIT 4ress, 5ambrid)e M?, pp. pp . +''&7#. Thomas, *., Knaus, 4. and 0et-, 1. #'%' 5omparison of the presynaptic (esicle component synaptophysis and )ap unction proteins8 a clue for neurotransmitter References to Chapter 8 143 releaseJ, in 3olecular iology of 1euroreceptors 1euroreceptors and $on Channels, edited by
?. Maeliche Sprin)er, 0erlin, 1eidelber).
Thorpe, B. 1. #':7 -nimal 1ature and Human - iologistAs
1ature Methuen,
*ondon. Thorpe, B. 1. #':% 2urpose in a
4orld 4orld of Chance.
Cni(ersity 4ress, A
/ 4uantum Aspects of %rain Acti,it! and the "ole of Consciousness 7. %eck and 6. C. 'ccles
/.1 Introduction= The Stor! of the ',entual Solution From #'%7 onwards I reali-ed that the Mar)enau story was inadeuate. Bhat was needed was a ri)orous mathematical treatment that would )i(e precision to the action of mental e(ents on neural e(ents, not ust the ill& defined probability field. Bhen I was attached to the 2euroscience @esearch 4ro)ram at the @ockefeller Cni(ersity for some months in #'%$ and #'%:, I or)ani-ed two mini&symposia in the hope that there could be pro)ress beyond the sta)e where Mar)enau left it in The 3iracle of Eistence. 1enry Mar)enau came to both these informal )atherin)s in 2ew 3ork. Cnfortunately Mar)enau and Bi)ner were not well enou)h to make the pro)ress that I hoped for. f or. !ohn ?rchibald ?rchibald Bheeler was unable to attend, but he nominated two physicists. I ha(e all the documents of these two most disappointin) proects. It was e(ident that the physicists did not reali-e that here was a )reat chance for uantum physicists. Ane physicist insisted that it could all be done by thermal physics, not uantum physics physics I still published on the mind&brain problem, for e
reali-ed that a key problem was to account for this low probability of e
/.2 4uantal Selection of %outon 'oc!tosis
There has been increasin) interest in recent years in the relation between uantum mechanics, brain acti(ity, and consciousness onald #'';E Mar)enau #'%7E Suires #'%%E Stapp #''#. An the part of uantum physics the impetus came from the interpretation of the measurement process, which is still bein) debated, e(en after more than si
howe(er, to the empirically established facts of brain physiolo)y, nor ha(e the authors attempted to locate a uantal process in the functional microsites of the neocorte<. In this work we contribute to fillin) this )ap by puttin) forward a uantum mechanical description of bouton e
Fi)ure '.la illustrates the uni(ersally accepted si< laminae of the neocorte< S-entN)othai #':% with two lar)e pyramidal cells in lamina ", three in lamina III, and two in lamina II. The pyramidal apical dendrites finish in a tuft&like branchin) in lamina I Fi)ure '.9a. There is a)reement by 4eters and Fleischhauer and their associates 4eters and Kara #'%:E Schmolke and Fleishhauer #'%7 that the apical bundles or clusters dia)rammatically shown in Fi)ure '.9b are the t he basic anatomical units of the neocorte<. They are obser(ed in all areas of the corte< that ha(e been in(esti)ated and in all mammals includin) humans. ?ppro
Figure 9.1 a ? three&dimension three&dimensional al
construct construct by S-entN)othai S-entN)othai #':% showin) showin) cortical neurons of (arious (arious types. types. There There are two pyramidal cells in lamina " and three in lamina III, one bein) shown in detail in a column to the right, and two in lamina II. b The detailed structure of a spine sp synapse on a dendrite denE st O a
a ? drawin) of a lamina " pyramidal cell with its apical dendrite showin) the side branches and the terminal tuft, all studded with spine synapses not all shown. The soma with its basal dendrites has an a
? ner(e impulse propa)atin) into a bouton causes a lar)e influ< of 5a 9U ions Fi)ure %.. The input of four 5a ions to a synaptic (esicle may cause it momentarily to open a channel throu)h the contactin) presynaptic membrane so that its total transmitter content is liberated into the synaptic cleft d in Fi)ure '.#b and Fi)ure '.+f, ) in a process called eocytosis. ?t most a ner(e impulse e(okes a sin)le e
64S4s deli(ered deli(ered by the decon(olution decon(olution analysis analysis of two 5?# pyramidal pyramidal cells were of uantal uantal si-es 997 " and #'+ Rmicro" with probabilities probabilities of ;.97 )n I + and ;.#$ )n I $, respecti(ely Sayer, @edman, and ?ndersen #'%'. For a systematic re(iew, see @edman #'';.
a ?n a
/.( A 4uantum #echanical #odel of 'oc!tosis
In the whole electrophysiolo)ical process of buildin) up the summed 64S4 e
Kandel, *ewin, and @eid #''+. There e
Figure 9." The collecti(e potential, potential, <)8+ for the motion of the uasi&particle of ener)y E ; which tri))ers e
characteri-ed by the instable situation in the 4"G after e
uestion of its embeddin) in lar)er surroundin)s at finite temperature. The situation is determined by two characteristic ener)ies8 i The thermal thermal ener)y, ener)y, E tht , h, which the uasi&part uasi&particle icle adopts in thermal thermal surroundin)s of temperature temperature uasi&particle with one de)ree of freedom this is )i(en by E th
=
# 9
T.
For our
'.#
7 0T
where k0 is the 0olt-mann constant. ii The uantum mechanical -ero&point ener)y, E ; of a particle of mass 3 locali-ed o(er a distance of _ 8. This follows from 1eisenber)/s uncertainty relation8
_ p_8 [ 9`` '.9 If we adopt the lower limit this would correspond to the )round state in a confinin) potential well we obtain, by identifyin) the momentum uncertainty, _ p, with its correspondin) kinetic ener)y, E ;
≈
F∆ pG
9
9 3
9
9π = ∆ 8
# 9 3
'.+
Be can can now define a borderline between the uantal and the t he classical re)ime by puttin) E ; I E thth
'.7
E ; E thth is then the 8uantal re)ime and E thth E ; the thermal re)ime.
For fi
'.
where 3 1 is the mass of the hydro)en atom. This estimate shows uite clearly that a uantum mechanical tri))er for e
9 ∂ ψ ∂ 9 ψ F 8E t G = − F 8E t G + < F8 Gψ F8E t G '.$ 9 3 ∂8 9 ∂t
The initial condition for t I ; sta)e I, be)innin) of e
∫ ψ F8E t Gψ F8E t Gd8
(9.7a)
left
p 9 Ft G =
∫ ψ F8E t Gψ F8E t Gd8
(9.7b)
right
are the time&dependent probabilities that e
'.%
and this is the conser(ation law which the probabilities ha(e to obey. The two parts of the wa(e packet at time t, left and ri)ht of the barrier Fi)ure '.7, are the two possibilities or states for which the indi(idual process can make a selection without any predetermined fiation. Selectin) one state or the other is the acausal process which (on 2eumann calls /reduction of the wa(e function/ "on 2eumann #'. The statistical probabilities prob abilities of 6uation '.: determine the freuencies of many repetitions of identical processes. For the indi(idual e(ent they only determine a tendency or /propensity/ 4opper #''; for selectin) one state or the other. The rele(ant time has to be defined as the duration of the uasi&stable situation in the paracrystalline 4"G, after which the metastable state chan)es into a stable one where no e
T = e
"
∫ a
9 3 R< F 8 G − E
d8 '.'
where a and " denote the classical turnin) points for the motion left and ri)ht of the barrier Fi)ure '.7. The probability per unit time for penetration of the barrier, , can be obtained by the number of attempts which the particle undertakes to reach the barrier, barrier, ;, times the barrier transmission t ransmission coefficient T/
d p
ω =
dt
'.#;
= ω ;T
where `; I E ; , , by appeal to 0ohr/s correspondence principle. 5ombinin) this with the )eneral considerations formulated after 6uation '.:, we obtain '.##
p5)W+ I W I W W ;T
?t this sta)e we can estimate estimate some numbers. *et us assume assume that the ener)y ener)y E I E ; of the initial initial state the wa(e packet locali-ed to the left of the barrier is the -ero&point ener)y of a wa(e packet locali-ed o(er the dimension dimension of the atomic site of the tri))er, tri))er, which we estimate rou)hly to be _ 8 # ], and let us take for the mass 3 of of our uasi&particle the mass of one hydro)en atom, 3 O O #.: < #; &97). Then we obtain, usin) 6uation &9 '.+, E ; %.+ < #; e". This leads to a freuency, from E ; O `; , , of ; #.+ < #;#7 s&#. 6stimatin) W, the time of the metastable instability, to be of the .order of electronic transition processes, that is, W #;&#+&#;s, we obtain from 6uation '.## p9)W+ #;T to to #;;T . Bith the obser(ed p9 of about ;.9 this )i(es for the barrier penetration factor T the reasonable span of 7 < #; &9 to 7 < #;&+. From these numbers we conclude that the tri))er process for e
ΨF#,..., 1 G = ψ i
#
F 9G
⋅ψ i
9
F 1 G
⋅ ⋅ ⋅ψ i
1
i @Ig;,#.
E
'.#9
0efore e
Ψ; F#,..., 1 G = ψ ;
F 1 G
⋅ ⋅ ⋅ψ ;
'.#+
The obser(ation that in response to a presynaptic impulse only one (esicle can empty its transmitter molecules into the synaptic cleft leads to a properly normali-ed wa(e function after the tri))er for e
# 1
F#G
Fψ #
F 9G
⋅ψ ;
F 1 G
⋅ ⋅ ⋅ψ ;
F#G
+ ψ ;
F 9G
⋅ψ #
F +G
⋅ψ ;
F 1 G
⋅ ⋅ ⋅ψ ;
F#G
+ ⋅ ⋅ ⋅ + ψ ;
F 1 −#G
⋅ ⋅ ⋅ψ ;
F 1 G
⋅ψ #
G '.#7
?ll other states are pushed up in ener)y by the lon) ran)e interaction so far that they cannot be e
/.* +eneration of 9eural ',ents b! #ental ',ents
In)(ar In)(ar #''; introduced introduced the term pure ideation, which is denned as co)niti(e e(ents that are unrelated to any on&)oin) sensory stimulation or motor performances. 1e stated that a study of brain structures acti(ated by pure ideation therefore appears to open up a new approach to understandin) the human psyche.
1e and associates at the Cni(ersity of *und introduced the study of the re)ional cerebral blood flow to display by cerebral ideo)raphy the acti(ity of the brain in pure ideation in all the immense (ariety )enerated by the psyche. 0y radio&
##
5haotic processes may play a role in patholo)ical situations.
Illustrat Illustration ion of the proposed proposed mind&brain interaction interaction by intentional intentional increase of the probability probability for e
Aur hypothesis of mind&brain interaction is summari-ed pictorially in Fi)ure '.. Its three components illustrate the effects of a weak a and a stron) b intention mental acts ust o(er # s duration or of ;.9 s c. Fi)ure '.d illustrates a pyramidal lamina " cell with its apical dendrite encrusted by the boutons of its synaptic inputE not all are shown, since they number up to ;;;. In Fi)ure '.a&c there are dia)rams of the action of a sin)le bouton with the back)round synaptic input, shown at a freuency of ; s &# short lines, that )enerates e
It has been proposed that this problem is illusory because the readiness potential is an artefact produced by the a(era)in) techniue of recordin). It probably arises because the intention to mo(e tends to be on the back)round of the risin) ne)ati(e phases of the slow 66G wa(es. Thus the readiness potential results from the cumulati(e a(era)in) of the back)round wa(es of ne)ati(ity. It can be reco)ni-ed that it is no more than the tendency of the conscious will to be so located in time in this back)round. It does not indicate, as has been assumed, assumed, that the "rain initiates the (oluntary mo(ement. This is done by the mind in the conscious will B, which *ibet finds to precede the 6MG by about 9;;ms 6ccles #'';, General iscussion, and 5hapter $ and which is illustrated in Fi)ure '.b, c. This dualistically based dia)ram Fi)ure '.b,c illustrates the mind&brain action in a way ne(er attempted by the materialist&monists, who rely on (a)ue (a)ue statements. It is important to reco)ni-e that, althou)h the intention to mo(e suffers the limitation that it can act only by alterin) the freuency of e
0ased on a careful analysis of neocortical acti(ity we ar)ue that e
r Stephen @edman in calculations of probabilities of release.
"eferences to Chapter / ?kert, K., 4eper, K., and Sandri, 5. #': in Cholinergic 3echanisms, edited by 4. G. Baser @a(en, 2ew 3ork, pp. 7+&:. eecke, *., and *an), ". #''; in The 2rinciples of Design and 0peration of the rain, edited by !. 5. 6ccles and A. 5reut-feld 6
into &ynaptic :unction, edited by G. M. 6delman, B. 6. Gall, and B. M. 5owan Biley, 2ew 3ork, pp. :&#;%. *ibet, 0. #''; in The 2rinciples of Design and 0peration of the rain, edited by !. 5. 6ccles and A. 5reut-feld 6
@esearch, Series 9# Sprin)er, 0erlin, 1eidelber), pp. #%&9;, plus General iscussion, pp. 9;:&9##. Mar)enau, 1. #'%7 The 3iracle of Eistence A< 0ow, Boodbrid)e, 5T. Messiah, ?. #'$# Fuantum 3echanics 2orth 1olland, ?msterdam, pp. 9+#&979. Mountcastle, ". ". 0. #':% in The 3indful rain, edited by F. 5. Schmitt MIT 4ress, 5ambrid)e M?, pp. :&;. 4eters, ?., and Kara, . ?. #'%: J. Comp. 1eural. 1eural. 9$;, :+&';. 4fennin)er, K., Sandri, 5., ?kert, K., and 6u)ster, 5. 1. #'$' rain #es. 12, #;&#%. 4opper, K. #''; - 4orld 4orld of 2ropensities 2ropensities Thoemmes, 0ristol. 4opper, K., and 6ccles, !. 5. #':: The &elf and $ts rain Sprin)er, 0erlin, 1eidelber). 4osner, M. I., 4etersen, S. 6., Fo<, 4. T, T, and @aichle, M. 6. #'%% &cience 97;, #$9:&#$+#. @edman, S. !. #''; 2hysiolog. #e'. #e'. :;, #$&#'%. @oland, 4. 6., *arsen, 0., *assen, 2. ?., and Skinho, 6. #'%; J. 1europhysiol. 1europhysiol. 7+, ##%&#+$. Sayer, @. !., Friedlander, M. !., and @edman, S. !. #''; J. 1eurosci. 1eurosci. #;, $9$&$+$. Sayer, @. !., @edman, S. !., and ?ndersen, 4. #'%' J. 1eurosci. 1eurosci. ^, %7&%;. Schmolke, 5., and Fleishhauer, K. #'%7 -nat. Em"ryol. Em"ryol. 1!9, #9&#+9. Suires, 6. !. #'%% :ound. 2hys. 2hys. %ett. #, #+&9;. Stapp, 1. 4. #''# :ound. 2hys. 2hys. 21, #7#::. S-entN)othai, !. #':% 2roc. #oy. #oy. &oc. &oc. %ondon 9;#, 9#'&97%. (on 2eumann, !. #' 3athematical 3athematical :oundations :oundations of Fuantum Fuantum 3echanics 3echanics 4rince&ton Cni(ersity 4ress, 4rinceton 2!, 5hap. I". Balmsley, 0., 6dwards, F. @., and Tracey, . !. #'%: J. 1eurosci. 1eurosci. :, #;+:&#;7$. Bi)ner, 6. 4. #'$: &ymmetries and #eflections Indiana Cni(ersity 4ress, 0loomin)ton, I2, pp. #+&#%7.
1: The Self and Its %rain= The @ltimate S!nthesis 1:.1 0ife and #ind
There were two absolutely unpredictable happenin)s in the story of the cosmos. The first was the ori)in of life, the second the ori)in of mind. If one asks where was mind or consciousness before it came to be e
1:.2 Self$%rain Dualism
Self&brain dualism demands primarily two authentic orders of e
In 5hapters 7 and self&brain dualism a)ain seemed to be a tenable hypothesisE but it is the dualism of Borlds # and 9 4opper and 6ccles #':: and not the 5artesian dualism of ennett and others, for e
?s I de(elop and illustrate the dualist philosophy there is concentration on the self, which is the uniue e
Figure 1/.1 Mean increases of r50F as a percenta)e
and their a(era)e distribution in the cerebral corte< under three different conditions of silent thinkin), as described in the te
by the pre(ailin) materialist reductionist philosophy. This philosophy is espoused in (arious )uises by neuroscientists without bein) subected to the philosophical e
materialis materialistt article article of faith, faith, because because it claimed claimed to account account for all e
Figure 1/.2 In )eneral, this fi)ure is similar similar to Fi)ure Fi)ure '., but it has two additional features. features. # ?s indicated, the mental influence shown by a row of circles of about # s duration is an attention. 9 The back)round 64S4 is shown to induce in the soma a back)round low&freuency&impulse dischar)e. If the probability were #.;, there would be a "ac7ground eocytosis for e(ery impulse in the upper row. So the mental attention could ha(e no action.
without infrin)in) the conser(ation laws of physics 0eck and 6ccles #''9 and 5hapter '. So Searle #'%7, p. '' see 5hapters +.% and +.' can continue with a )ood conscience to en)a)e in (oluntary, free, intentional actions The self action on the brain neocorte< can presumably be e
materialist cacophony of structuralism and functionalism culminatin) in roboticism The theme son) should be The &orcererAs -pprentice
1:.( Ideation and 7ree
The r50F in(esti)ation by @oland #'%# on the effect of mental attention on the neocorte< has already been illustrated Fi)ure $.#9. ?ttention was focused on a fin)er tip in e
can influence the neocorte< of conscious human subects. There was a special attempt to locali-e the cerebral areas acti(ated in co)nition. For e
1owe(er, selecti(e attention appears to use neural systems separate from those in(ol(ed in passi(ely collectin) information about a stimulus. If acti(e selection or (isual search is reuired, this is done by a spatial system that is deficient in patients with lesions of the parietal lobe. Similarly, in the anterior brain, the lateral left frontal lobe is in(ol(ed in the semantic network for codin) word associations. *ocal areas within the anterior cin)ulate become increasin)ly in(ol(ed when the output of the computations within the semantic network is to be selected as a rele(ant tar)et. Thus the anterior cin)ulate is in(ol(ed in the computations in selectin) lan)ua)e or other forms of information for /action/. In the study of (isual ima)ery, ima)ery, models distin)uish distin)uish between between a set of operations operations in(ol(ed in(ol(ed in the )eneration )eneration of an ima)e and those in(ol(ed in scannin) the ima)e once it is )enerated. 4osner et al. #'%, p. #$+;
0y 46T scannin), 5orbetta et al. #''; showed that attention enhanced the acti(ity of different re)ions of e
For e
1ere is a clear affirmation of the concept that mental e(ents attention can acti(ate neural e(ents as is indicated in Fi)ure #;.9, which is a sli)ht modification of Fi)ure '.. The four beautiful colour displays of Fi)ure #;.+ )i(e wonderful illustrations of the specific cerebral acti(ities induced by a wide (ariety of attentions and selections durin) lin)uistic performances. It can be predicted that e(entually all of the neocorte< neocorte< will be shown to respond focally by specific specific acti(ities, by usin) this 46T scannin) techniue. The limited testin)s so far studied ha(e re(ealed a wide ran)e of cortical acti(ation, so it can be e
Figure 1/.3 4ositron
emission tomo)raphy 46T scans of the cerebral corte< of conscious human subects performin) four intellectual tasks relatin) to words. The 46T techniue re(eals that the blood flow si)nallin) the acti(ity of the neocorte< is sharply focused in specific locations dependin) on the lin)uistic tasks bein) performed. The colour scale to the right shows the wide ran)e of cortical acti(ities. r Marcus @aichle of the Bashin)ton Cni(ersity School of Medicine in St *ouis made the ima)es in #''9 and has kindly pro(ided them for my book.
is of (ital importance in the whole ran)e of our e
Tra)ically and absurdly misunderstood is the wonder and mystery of the human self with its spiritual (alues, with its creati(ity, and with its uniueness for each of us. 4enrose in his book The EmperorAs 1ew 3ind, which I ha(e abstracted from in 5hapter +.:, has e
arwin arwin +, but it is for display and )rant support support It is of no (alue in helpin) to understand understand the brain. It is (ery re(ealin) to disco(er in all the massi(e literature on consciousness and ?I that there is no reference to the three fundamental disco(eries that are the basis of the scientific hypothesis of the self&brain interaction in 5hapter ' see Fi)ures '. and #;.98 # 9 +
The presynaptic 'esicular grid with its e8uisite design for eocytotic pro"a"ility. The eocytotic pro"a"ility with its low le'el that gi'es great opportunity for enhancement "y the mind without infringing the conser'ation laws. The "undli "undling ng of apical apical dendri dendrites tes of pyrami pyramidal dal cells cells into into dendr dendrons ons that that pro'i pro'ide de the necess necessary ary great great amplification of the milli(E2&2s produced "y each eocytosis.
It is ama-in) ama-in) and (ery disturbin) disturbin) that all the )reat )reat scientific scientific efforts efforts in the attempt to understand understand the brain display blindness to the microstructures and microfunctions of the neocorte<. 4enrose #''# did reali-e the necessity for scientific study of the neocorte<, but he did not disco(er the essential microle(els of understandin). Sperry was ho(erin) in the ri)ht direction in his reection of materialism, but he missed the necessary microunderstandin). Searle #'%7 reects the pro)rammes and claims of the artificial intelli)ence ad(ocates. ?s Searle states8 The pro)rammin) of a computer is entirely syntactical, but the mind has more than a synta<, it has a semantics. p. +#
Searle concludes8 2o computer pro)ram by itself is sufficient to )i(e a system a mind. 4ro )rams, in short, are not minds, and they the y are not by themsel(es sufficient for ha(in) minds. The proect of tryin) to create minds solely by desi)nin) pro& )rams is doomed from the startE whereas consciousness, thou)ht, feelin)s, emotions and all the rest of it in(ol(e more than a synta<. These features, by definition, the computer is unable to duplicate, howe(er powerful may be its ability to simulate. ?nd no simulation by itself e(er constitutes duplication. p. +:
?s stated in 5hapter ' all the uantum physicists failed because their approach )ot no further than )eneralities, rather like electricity before electrons and li)ht before photons. This scientific failure can be attributed to the pre(ailin) materialism with its superstitious beliefs. Bhat I find particularly disturbin) is the claim of the ?I operators that they are on the (er)e of supercomputers that will e
1:.; The Ps!chon
The most e
!ames made an e
auditory or tactual or mo(ement e
4roblems relatin) to the e
This conclusion is of inestimable theolo)ical si)nificance. It stron)ly reinforces our belief in the human soul and in its miraculous ori)in in a di(ine creation. There is reco)nition not only of the transcendent God, the creator of the cosmos, the God in which 6instein belie(ed, but also of the immanent God to whom we owe our bein). I here e
The title of this book How the &elf Controls $ts rain was chosen to be a clear challen)e. It also harks back to the book I wrote with 4opper8 The &elf and $ts rain #'::. It contr contras asts ts with with the the con( con(ol olut uted ed )ene )enera ralilitities es of atte attemp mpte tedd mate materi rial alis istt soluti solution onss for for the the ori) ori)in in of consciousness, as is illustrated in the abstracts in 5hapter + for 5han)eu<, ennett, and 6delman, after eingdom or the Dar7nes Dar7ness. s. Monod has )i(en o(er his chapte chapterr of his #':# book, book, called called appropria appropriatel telyy The >ingdom rationality for his ultimate role of a prophet, as has been reco)ni-ed in se(eral re(iews of his book by Thorpe, 5ournand, and others. 2ow for the first time in the article by 0eck and myself #''9 that forms 5hapter ' there is presented the scientific hypothesis of how the self may control its brain without infrin)in) the conser(ation laws. This is our continual dualist e
fundamental basis for our conscious world and all its transcendent creati(ity, which we (alue in the conscious self with its control of the brain in the /1AB/ of this book. "eferences to Chapter 1: 0eck, F., and 6ccles, !. 5. #''9 Luantum aspects of brain acti(ity and the role of consciousness, 2roc. 2roc. 1at. -cad. &ci. %', ##+:. 5orbetta, M., Mie-in, F. M., obmeyer, S., Shulman, G. *., and 4etersen, S. 6. #''; ?ttentional modulation of neural processin) of shape, color and (elocity in humans, &cience 97%, #+$&#+'. ennett, ., and Kinsbourne, M. #''9 Time and the obser(er. The where where and when of consciousness in the brain, eha'ioral eha'ioral and rain &ci. &ci. #, #%&97:. 6ccles, !. 5. #'%' E'olution of of the rain/ Creation Creation of of the &elf @outled)e, *ondon. 6delman, G. M. #'%' The #emem"ered 2resent/ - iological Theory of Consciousness 0asic 0ooks, 2ew 3ork. 3ork. Fei)l, 1. #'$: The A3entalA and the A2hysicalA Cni(ersity of Minnesota 4ress, Minneapolis M2. 1od)son, . #''# The 3ind 3atters 3atters 5larendon, A
+lossar! A+tion 0otenti#l ? brief re)enerati(e, all&or¬hin) electrical potential that propa)ates alon) an a
i.e. opposite to the usual orthodromic direction. Ar#+hnoi &ee 5erebrospinal fluid. Ar$ori#tion The branchin) of ner(e fibres. Astro+tes &ee 2euro)lia. Attention 5oncentration on some sensory e
Cere$ru( The principal anterior part of the brain. Ch#nnel ?n openin) or /pore/ in a membrane throu)h which ions or molecules can mo(e. Cogniti4e e0erien+e ? conscious thou)ht or e
electricity.
Contr#l#ter#l @elatin) to the opposite side of the body. Con4er Con4ergen gen+e +e The comin) to)ether and makin) of synapses
a circuit to conduct
by a )roup of presynaptic neurons on one
postsynaptic neuron. Coron#l se+tion ? (ertical section throu)h the skull at ri)ht an)les to the front&back sa)ittal a
eninges Glial co(erin)s of the brain. E77 Miniature end plate potentialE a small
depolari-ation at a neuromuscular synapse caused by spontaneous release of a sin)le uantum of transmitter from the presynaptic terminal. esen+e0h#lon The lower lower medial part part of the brain. Modali Modality ty The class class of sensation sensation e.). e.). touch, (ision, (ision, smell. otoneuron )(otor neuron* ? neuron that inner(ates muscle fibres. otor unit ? sin)le motoneuron and the muscle fibre it inner(ates. us+le s0inle ? fusiform end or)an in skeletal muscle in which afferent sensory fibres and a few f ew motoneurons terminate. elin The white substance of fused )lia ensheathin) ner(e fibres. Neo+orte The most recently de(eloped part of the cerebral corte<, composin) the cerebral hemispheres. Ner4e -i$re ?n a
Small membrane&bounded sacs contained in presynaptic ner(e terminals. Those with dense cores contain catecholamines and serotoninE clear (esicles are presumed to be the stora)e sites for other trans& mitters. =hreshol #. The critical (alue of membrane potential or depolari-ation at which an impulse is initiated. 9. The minimal stimulus reuired for a sensation. =r#ns(itter ? chemical substance liberated by a presynaptic ner(e terminal causin) an effect on the membrane of the postsynaptic cell, usually an increase in permeability to one or more ions. =ro0hi+ in-luen+e ?n action from one part of a cell to another, or from one cell to another, that is concerned with the )rowth, maintenance, and metabolism of the cell. ;entr#l Towards Towards the under or belly side of the body. bod y. ;entri+les 5a(ities within the brain containin) cerebrospinal fluid and lined by ependymal cells. >hite (#tter 4art of the central ner(ous system appearin) whiteE consistin) of myelinated fibre tracts.
Sn#0ti+ 4esi+les
