Wittgenstein On Psycho Physical Parallelism - Dr Peter Hacker

to give up generous tribute I'm most grateful um written writing in 19467 Ludi Vicken Stein made some

observations on conceptions of neural representations and correlations between thought processes and brain processes that pre 21st century

debates they are highly controversial they have occasioned multiple conflicting interpretation ations and misunderstandings although written more

than 75 years ago they retain their freshness and forcefulness if correct they undermine some of the deepest preconceptions of

contemporary cognitive neuroscience and neurology as well as experimental psychology binstein wrote as follows and

the quotations come from tle 608 following no supposition seems to be more natural than that there is no process in the brain correlated with

associating or with thinking so that it would be impossible to read off thought processes from brain processes I mean this if I talk all

right there is I assume a system of impulses going out from my brain and correlated with my spoken or written thoughts but why should the system

continue further in the in the direction of the center why should this order not proceed so to speak out of chaos the case would

be like the following certain kinds of plants multiply by seed so that a seed always produces a plant of the same kind as that from which it was

produced but nothing in the seed corresponds to the plant which comes from it so that it is impossible to infer the properties or structure of the plant from those of the seed that comes

out of it this can only be done from the history of the seed so an organism might come into being even out of something quite amorphous as it were

causelessly and there is no reason why this should not really hold for our thoughts and hence for our talking and

writing it is therefore perfectly possible that certain psychological phenomena cannot be investigated physiologically because physiologically

nothing corresponds to them I saw this man years ago now I see him again recognize him remember his name and why does there have to be a

cause of this remembering in my nervous system why must something or other whatever it may be be stored up there in any

form Why must a trace have been left behind why should there not be be a psychological regularity to which no physiological regularity regularity

corresponds if this upsets our concepts of causality then it's high time they were upset

unquote these passages May well seem shocking Anthony Kenny one of the foremost wienstein Scholars of his day and a viin a vien steinan philosopher of

psychology found himself unable to to foll in Vicken Stein's footsteps he wrote as follows since the time of Galileo it has

been a presumption of science that every Power has a vehicle that to every potentiality for the future there corresponds a present

actuality it is this presumption that wienstein is here calling into question he is undoubtedly correct that there's nothing conceptually

incoherent in the idea of a capacity exist without a material vehicle but one must ask whether and if so when it can be reasonable for science

simply to give up the Quest for a vehicle I share the queasiness about this passage that is widespread even among VI Stein's

admirers much of History suggests that scientific progress is made by inquiring into the vehicles of capacities rather than by treating capacities such as

normative Powers as the basic building blocks of science maybe wienstein is right that in Aristotelian terms there may be formal and final causes in the absence of

efficient and material ones perhaps there can be but one cannot help wondering whether vid canstein May here be adopting towards contemporary

neuroscientists the attitude that Renaissance aristotelians adopted to Galileo unquote there is indeed no disputing

that paradigmatic Natural Sciences such as physics and chemistry have advanced as a result of searching for structures that underly powers of things and stuffs

in nature this is true of some parts of some Sciences it is not true of Newtonian

physics for example nor is it true of Relativity Theory binstein however Avers the plausibility of the idea that there is no process in the brain that is

correlated with associating or thinking if so then to be sure it will not be possible to read off one's spoken or written thoughts from neural cortical

events there will be no neural representation of the thoughts one expresses is viernstein denying a

vehicle for individual thoughts expressed the question's puzzling since is Powers some powers that are said to have

vehicles the power vehicle relation is generic same power same vehicle alcohol quite generally is the vehicle of the

intoxica power of whiskey so is one to suppose that whenever anyone exercises the power of thinking whenever anyone expresses the

thought that such and such there is an identical neural substrate or vehicle in their brain this has no plausibility whatsoever given the differences between

the brains of different individuals at the micro level of neurons synapses and dendroides is want to suppose that whenever a given human being exercises

power of thinking and expresses the specific thought that say Jack was wise to immigrate in speech or writing the

very same neural structure is the vehicle even if the reiteration of the thought is separated by 20 years from its original

expression given the dynamic character of the brain this too seems anything but plausible an alternative to the generic relation between power and vehicle is

the is the idea that there can be no psychological event without a correlated physical neural cortical event it might be thought that any

psychological event must be supervenient on actical change hence too any individual expression of thought such as my

assertion that P must be supervenient on a neural event this to be sure is a much weaker position than the previous one it is not

committed to a generic representation but only to a singular so-called token correlation but this is no longer a

verifiable empirical hypothesis since billions of neural events are doubtless occurring in a human being's brain when on some specific occasion he expresses his

thought that P which one of these is supposed to be correlated with the agents thinking that P how might this be

established what is to count as a token correlation or is the claim that the psychological event is identical with some physical neural

event but this is surely to move from the unverifiable to the unintelligible I might pause you and explain why it's unintelligible event

identity if if event e is identical with E1 is identical with E2 well one Criterion of event identity requires the identity of the substance undergoing the

change but the change that's going on in the brain is a change to the brain and the change involved in the human being who's speaking and expressing the thought or merely thinking the thought

is a human being and human beings aren't brains so you don't have a case of brain identity of of event identity that was

what I'm alluding to now I won't discuss this here as this philosophical Theory broadly David sonian I suppose was not vien Stein's concern in the passages we

are examining so undismayed we can now return to the careful examination of Vin Stein's discussion the first part the first

paragraph has interpretive difficulties the analogy with the seeds of the plant is unclear does wienstein mean in that in

the case of plants we should surely dismisses Preposterous the idea that nothing in the seed corresponds with the character of the plant which produced it so that it's impossible to infer from

the properties of the seed the features of the plant that will grow out from it but that this stands in dramatic dramatic contrast to thinking and

remembering this might at fcal Art seem plausible but that's not what venin had in mind at all the reflection on genetic causality anti dates the discussion of

psychophysical parallelism by a decade and was independent of any questions about it it first occurs as far as I know in manuscript 199 written on the

22nd of septe 26th of September 1937 and vetstein wrote and I quote from the manuscript think of two different kinds

of plants A and B both of which yield seeds the seeds of both kinds look exactly the same and even after most careful investigation we can find no

difference between them but the seeds of an a plant always produce more a plants and the seeds of a b plant more B plants in this situation we can predict

what sort of plant will grow out of such a seed only if we know which plant it has come from are we to be satisfied with this or

should we say there must be a difference in the seeds themselves otherwise they couldn't produce different plants their previous Histories on their own can't

cause their further development unless their histories have left traces in the seeds themselves but now what if we don't

discover any difference between the seeds and the fact is it wasn't from the peculiarities of either seed that we made the prediction but from its

previous history if I say history can't be the cause of the development then this does not mean that I can't predict the

development from the previous history since that's just what I do it means rather that we don't call that a cause of connection that this is not a case of

predicting the effect from the cause and to protest there must be a difference in the seeds even if we don't discover it doesn't alter the facts it

only shows what a powerful urge we have to see everything in terms of cause and effect a slightly different variation on the last sentence is it only shows how

powerful the cause effect schema is in us that's the end of the quotation binstein is not denying the fruitfulness of the commitment of

biological science in general and of botony in particular to the schema of cause and effect what he's pointing out is that the must

does not lie in nature in the facts but in our commitment part to a particular form of explanation namely an explanation in terms of efficient

causality to be sure a farmer predicts what plants his seeds will yield from the history of the seeds their last year's

crops but that is not what we call a causal explanation we insist that there must be a structural genetic explanation for why

these seeds produce this plant and those seeds produce that plant but the must shows something about us not about the facts

discovered it is vien Stein insists perfectly intelligible for prediction to be divorced from causal determination for the terminal State the

production of the plant of the specified type need not be derivable from any intervening structure that's perfectly intelligible now this analysis is

confirmed by other notes from manuscript 159 written in English that are printed as appendix a to what is now called cause and effect intuitive

awareness they seem to be notes for lectures given in Spring 1938 it opens with a a little dialogue I know what seed will sir I

know what this seed will give it will give a poppy why because it came from a poppy to say it will give a poppy

because it came from a poppy would be disagreeable whereas I know it will because it came for a propy is not so there is something like action at a

distance here which shocks people the idea would revolutionize science a seed that has come from a poppy will produce a poppy that's all

right but not it will produce a poppy because it came from a poppy today in case we actually discovered two seeds which we could not

distinguish but one producing a poppy in the other a rose we should look frantically for a difference but in other circumstances we

might give this up give up looking for a difference this would be a tremendous thing to do as great as recognizing

indeterminacy we would no longer look for the difference and so we would no longer say there must be a difference now today we have every

reason to say that there must be a difference but we could imagine circumstances where we would break with this tradition

unquote this I think is a remarkable anticipation of neural network Theory and this incidentally has been powerfully argued for by Professor Nev

at University College London to occur in neural networks generating the same output from the same input now how does all this bear upon

psychophysical parallelism when I talk or right thereby articulating or expressing thoughts I move my larynx mouth MTH lips perhaps

gesture with my hands and so forth or I move my hand and figers fingers in order to write so a system of neural impulses is

sent sent from my brain say from the premotor and motor cortex these impulses are indeed correlated with my spoken or written

thoughts that is different words added or written would need different streams of impulses producing different movement M

ments this wienstein considers to be uncontroversial but now should the system not continue further in the direction of the Centum for example in

the direction of the prefrontal coures is not the Genesis of the thought in question to be found in specific activity of the so-called cogitative

centers of the brain must the thought expressed not of Arisen in highly specific neural activity in the cortex such that one could read off the

thought from it so every thought must have a neural representation there is no must about it

there is nothing incoherent in the supposition that the specific thought uttered or inscribed have no determinate neural cause of which one can read it

so the idea of psychophysical parallelism is unjustified why should the order the coherence and cency of the verbal

expression of the thoughts not proceed so to speak out of chaos that is out of neural dynamics that are so unpredictable as to appear random of

which the thought cannot be read in another passage written a little later on the 16th of December in 1948 binstein not only reaffirmed his view

but also expressed confidence that this view would in the fullness of time become accepted quote indeed I confess nothing seems more possible to me than that

people someday will come to the definite view that there is no copy in either the physiological or the nervous system which corresponds to a particular

thought particular idea a memory unquote Vicken Stein's view can be supported by the following Reflections there is no reason for

supposing that there is let alone that there must be a systematic structure or process of which it's possible to read the thoughts uted or inscribed when

someone says or writes what he thinks to understand why I said said or wrote 1314 one needs to know the context and

history of my utterance or writing I may have been asked for Jack's telephone number or asked for the date of the battle of

bagburn or asked for the date of the battle of Adin court and mistakenly written this answer or asked to write the next two numbers after

12 or asked for the time of the next train to London and so on and so forth no neural story can supply the

answer the qu to the question of why I thought 1314 hence section 6 nine maybe certain

psychological phenomena cannot be investigated physiologically because nothing physiological corresponds to them section

610 moves from thinking and giving verbal or written expression to a specific thought to recognition and remembering Trace Theory provides a

familiar concrete example to strengthen Vicken Stein's case he was familiar with James's advocacy of Trace Theory and with the

gestal psychologist Vol Kang kers early in TS 229 which is now remarks on philosophy of psychology volume 1

Section 220 he had already touched on the matter I quote an event leaves a trace in the memory one sometimes imagines this as

consisting in the events having left to trace an impression a consequence in the nervous system as if one could say even the

nerves have a memory but then when someone remembered an event he'd have to infer it from this impression this

Trace whatever the event does leave behind in the organism it isn't the memory the organism compared with a

Dictaphone spool the impression the trace is the alteration in the spool that the voice leaves behind can one say that the dictaphone

the spool is remember what was spoken all over again when it reproduces what it recorded unquote to be sure when the answering

machine on a modern phone is recording it's not committing anything to memory and the alterations on its chip like the alterations on the spool of the dictaphone are not

Memories similarly when the recordings are played the machine is not remembering anything the bearing of this on Trace

theories of memory is patent James had written in 1890 that I quote the retention of n it will be

observed is no mysterious storing up of an idea in an unconscious state it is not a fact of the mental

order at all it is a purely physical phenomenon a morphological feature the presence of these part paths namely in

the finest recesses of the brain's tissue the recall or recollection on the other hand is a psychophysical phenomenon with both a bodily and a

mental side the bodily side is the functional excitation of the tracts and paths in question the mental side is the

conscious vision of the past occurrence and the belief that we experienced it before of course Trace theories of memory go back to a metaphor in Plato that was

concretized by Aristotle in Doria Aristotle alas held that the functional adequacy of mmory traces depended on the condition of the tissue

if it's insufficiently firm as in babies or too dry as in the sence ccent no Trace will be left not incidentally a million miles removed

from current Neuroscience neuroscientific Theory just the difference in the jogon so that was James interestingly 57

years later Wulf K kler wrote in a similar vein I quote what does recognition mean it means that a present fact

usually a perceptual one makes contact with a corresponding one in memory a trace a contact which gives the present perception the character of being known

or familiar but memory contains a tremendous number of traces all of them representations of previous experiences

which must have been established by the processes accompanying such earlier experiences now why does the present perception make contact with the right

earlier experience this is an astonishing achievement nobody seems to doubt that the selection is brought about by the

similarity of the present experience in the experience of the corresponding earlier fact but since this earlier experience is not present at the time we have to

assume that the trace of the earlier experience resembles the present experience and it is this similarity of our present experience or corresponding

cortical process and that Trace which makes the selection possible elsewhere he wrote all sound theories of memory of habits and so

forth must contain hypothesis about memory traces as physiological facts such theories must also assume that the Char characteristics of traces are more

or less akin to those of the processes by which they've been established otherwise how could the accuracy of recall be explained

unquote with the passing of time and the enlargement of knowledge about brain functions the tale became more complex and I quote from Ian

Glenn in 1999 since the episodes that give rise to Memories involve a variety of perceptions it seems like clear that the

laying down of such memories involves nerve cells in the association areas and in secondary or higher quartic areas concerned with the different senses it

is also likely that recalling memories involves recreating something like the original pattern of activity in those same sets of cells or at least some of

them initially then both the hippocampus Zone and the neocortical Zone must act together eventually when consolidation is compl complete the memories are

stored in such a fashion that they are available without involvement of the hample Zone implying that storage is then wholly in the neocortical zone

unquote I shall pause a moment to draw some important distinctions it's noteworthy that there was extensive confusion about the use of

the expression memory and its cognates it was was taken for granted by many neuroscientists that what is

remembered the object of memory is past experience but to remember learning something is altogether different from remembering what was

learned most of what we have learned and remember does not involve recollecting the learning of it what we remember need not be of the

past at all since we may remember what we have to do tomorrow or next week we may remember General omn temporal facts as such as are expressed by statements

of laws of nature we remember we may remember atemporal data such as the laws of logic and theorems of mathematics that's the first distinction

to bear in mind here a related confusion is a consequence of failing to apprehend the multiv valent character of the term

memory and remember to mean in one context the actual recollection as a given time and place in another the power to recollect

or bring something to mind and in the third to signify not the remembering but what is remembered as when we say my memory is that it's a 3 p.m. or as far

as I remember it's at 300 p.m. now in any scientific discussion of

p.m. now in any scientific discussion of memory it must be determined which sense of memory is in play that is how we talking about the

faculty are we about talking about an exercise of the are we talking about retention or are we talking about the exercise of the faculty on a particular

occasion in more recent times Eric candell was awarded the Nobel Prize for his pathbreaking work on memory he worked on the Gill with draw

reflex of a plasia the C slug A Primitive organism the neurons of which are exceptionally large and H hence relatively amenable to

experiment it should be noted in passing that a reflex is not memory involving at all and the acceleration of a reflex in

response to recurrent exposure to a stock stimulus is not an example of memory or recol elction memory rather crudely speaking

for the moment is retention of knowledge or information Acquired and experience for example I know now because I leared previously this however was not how

candell saw matters together with his colleague Squire he avered that I quote every sensible experience involves cortical

changes these cortical Chang changes once Consolidated imprinted are stored Memories the consequent theories of

memory explicitly insist that quote the resulting memories are stored as changes in strength at many synapses within a

large Ensemble of interconnected neurons and quote that's from Squire and kandell in 1999 this conception which is

susceptible to the challenge of settle 610 victon Stein's remark on memory traces is defected for multiple reasons

of which I shall mention three first it confuses storage with retention one can store information in a

notebook on a card index in a filing cabinet on a computer or recording device by means of a photograph or a drawing

but there is no such thing as storing information in brains or synaptic connections stores of information contain

information but an agent that retains information possesses it human beings can retain information antecedently acquired they learn things

that is they acquire the abili characteristic of n what was learned and do not forget what they learned so they can now act on what they

learned reason from what they learned to new conclusions they experience things and can say what they experience if they do not forget then

they retain the ability to act on what they experienced that is to act or refrain from action for the reason that such and such storage is irrelevant what

is necessary is the Persistence of cognitive Powers secondly it fails to render intelligible the notion of storing experiences in

memory traces it is wholly opaque what is meant by storing an

experience one may experience various things perceive perceptibility participate in various activities acquire information by being

taught and one may learn how to do things all this and very much more may be deemed to be

experiences it is as R might put it a portmanto word however the term experience is equivocal it may signify the

experiencing or what is experience experienced now one can't store experiencing something at most one can store a description of the experiencing

or capture the experience on film which can be stored can one store what is experienced the question is too General

and nebulous since the very term experiences is such a catchall suppose one perceived something and notes that the objects of perception are indefinitely numerous in category

and kind can one store what one experienced a butterfly in Flight a noise a Sonata a

person a landscape a view one can often remember what one experience and recount it or call it to mind act on the basis of it or dwell on

it like Wordsworth on daffodil or tins and Abby in Fond recollection but can one store it in memory traces

thirdly it conceives of the alleged memory traces stored in the brain in the form of changes in strength of synaptic connections as representations of what

is remembered but this is not intelligible whatever A Memory Trace may be it can be neither semantic a sentence

stating what is remembered nor iconic a pi picture or image of what is remembered for the brain contains neither sentences nor images and changes

in the strength of synaptic connections are not representations of anything might they then be simply causal correlates instances of

psychophysical paral parallelism we've already shown this idea to be mistaken since type type correlation is empirically wildly imp

plausible and token token cor correlation makes no sense since there could be no such correlation the Assumption of the

necessity of a causal chain between antecedent neural events coincident with information acquisition and current recollection is part and parcel of our

preconceptions about psychophysical parallelism it is I think logically flawed one may know now something one

experienced became aware of or came to know in the past one may often be said to remember now the information one acquired in the past which need not be

about the past one may be said to remember now because one acquired the information previously but no Trace need be invoked

in order to render intelligible the retention of information acquired that is not having forgotten hence wienstein

concludes I quote again the Prejudice in favor of psychophysical parallelism parallelism is a fruit of primitive interpretations of our

concepts for if one grants causality between psychological phenomena which is not mediated physiologically one thinks what is professing belief in a gaseous

mental entity that's T six 11 there's an alternative in remarks on

philosoph philosophical remarks on philosophy of psychology volume 19 196 which I'll read out too the Prejudice in favor of psychophysical parallelism is also a

fruit of a primitive conception of grammar for if one grants causality between psychological phenomena which is not mediated physiologically one fancies that in so

doing one is making an admission of the existence of a mind alongside the body a ghostly mental being

unquote binstein is not denying that a multitude of changes in the brain may occur when one experiences something that some one subsequently

remembers indeed it may well be that but for these unknown Transformations we would not remember what we can and do remember what he is denying is that

these trans formations are in any sense stored memories or representations he clarifies his point with what I think is a felicitous

example imagine the following phenomenon if I want someone to take note of a text that I recite to him so that he can repeat it to me later I have

to give him pencil and paper while I'm speaking he makes lines marks on the paper if he has to reproduce the text later he follows those marks with his

eyes and recites the text but I assume that what he's jotted down isn't writing it's not connected by rules with the words of the text yet without these

jottings he's unable to reproduce the text and if anything in it is altered If part of it is destroyed he gets stuck in his reading or recites the text

uncertainly or carelessly or cannot find the words at all this Can Be Imagined what I call jottings would not

be a rendering of the text not a translation so to speak in another symbolism the text would not be stored up in the

jottings and why should it be stored up in our nervous system unquote binstein concludes the sequence of remarks with an observation that is

of the greatest significance why should not the initial and terminal states of a system be connected by a natural law which does

not cover the intermediate state only don't think of causal efficacy don't think of caal agency now what he's envisaging is a

regular connection he calls it here a natural law meaning a natural as opposed to a normative regularity a natural regularity as opposed to a normative

regularity so what he's envisaging is a regular connection between input hearing the text and output repeating the text with without any causal links representation that could be said to

determine the output as I mentioned before it's been argued by Professor Nev at Queen Square neurology Center at University College London that this is precisely what is

exemplified by artificial neural networks the theory of which was in effect anticipated by Vicken Stein here if that is so it's a rather interesting case of functionally convergent

evolution so to speak the evolution of the brain on the one side and of machine learning on the other be that as it may it seems that

there is no reason to suppose that the connection between a past experience and a present recollection of a past experience or of information gained or

retained from that experience is mediated by an internal cortical representation indeed there is every reason to suppose that this is a

conceptual confusion for what is recollected is the past experience or information gleaned from such an

experience what I remember is say my breaking my ankle or sitting examinations my examinations or your winning the race his death or her

wedding wedding not some fa simile thereof when I remember Jack and Jill it's Jack and Jill themselves that I remember not a representation of them

which is the case if I remember a portrait of them because a portrait is a representation the connection is logical

it's a case of identity not of causality it requires no causal intermediary indeed a causal

intermediary is to be sought precisely in those cases when one does not actually remember but only seems to remember because for example one has

been recurrently told of of the past experienc innumerable times Say by one's parents these recurrent narrations of the past are indeed causal

intermediaries causal intermediaries that are absent in cases in which one does remember that last thought is derived

from my dear late friend be Randall thank you very much