Reprinted from: KRISIS (the journal of the International Circle forResearch in Philosophy~ Houston, TX), 1985, pp. 14-31.

Karl PribramA SCIENTIST'S APPROACH TO THE

MIND/BRAIN ISSUE

On several occasions I have beentold by philosopher~ that whateverscientists accomplish in the laboratory,it will have no bearing on the problemof the relationship between mind andbrain: The mind/brain problem is alogical one and data are irrelevant,they say. Since my research career isdevoted to collecting data which I be­lieved relevant, I found such statementsdisconcerting. My hope was that suchdata would resolve the issue of mental­ism in psychology, much as the syn­thesis of the organic compound ureafrom its inorganic constituents andother biochemical achievements of thenineteenth century had resolved theissue of vitalism in biology.

This hope has been shared by thosewho have followed closely the tenets ofoperationalism which resulted in classi­cal behaviorism. Elsewhere (Miller,Galanter and Pribram 1960, Pribram1962, 1965, 1970, 1971, 1973, 1976a,1976b, 1978a, 1978b, 1980, 1981 a,1981 b), I have reviewed not only theharvest of data, but also the reasonswhy the solutions proposed by classicaland radical behaviorism have failed.

Essentially, this failure is due tothe attempt to ignore, or to dismiss astoo unwieldy for scientific analysis, thesubjective reports of experience ratherthan to deal with them on their ownterms and in their own terms, and tointegrate these reports with other as­pects of behavior. The- failure becameespecially pronounced when clinicalneuropsychological observations. becamequantified as a result of powerful toolsdeveloped in cognitive experimentalpsychology.

Here I want to take the 0pp'or­tunity to discuss an alternative proposalin terms of a "subjective behaviorism,"

as we called it in Plans and the Struc­ture of Behavior (Mille~Galan~&Pribram, 1960). The proposal does notdepart from the necessary attempt tooperationize definitions. However, re­ports of subjective experience made innatural language are not only admittedas scientific evidence and analysis, butas ontological primitives of vital inter­est to scientific psychology. If indeedpersons report that they experiencefreedom or dignity or their losses, suchstatements are not dismissed as un­scientific but accepted as the very rootissues whose .mechanisms in brain,hormones, society or culture need to bediscovered. Within such a frame, mind/brain issues can be cast logical!y andthe results of neuropsychological re­search made relevant to philosophy.

My proposal does not eschew philo­sophical discourse. Philosophers haveargued the issues, and in the processhave clarified the statements whichrepresent the issues. Philosophers haveidentified the questions which must beanswered if the mind/brain issue is tobe resolved. And philosophers have out­lined the course of argument whichmust be entertained if the resolution isto hold firm.

However, two millenia of philo­sophical discourse have not broughtresolution. It is fair to asi<:'therefore,whether some additional insights mightnot be gained by going about resolvingthe problems in. some other fashion. Inother fields of endeavor, such as phys­ics, scientific discoveries have had animpact on philosophical discourse.

The relationship between mind andbrain has, of course, been thoroughlyexplored during the past two centurieswith a variety of anatomical, electro-

"e!,!ysiological, neurosurgical, and neuro-

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Karl Pribram

chemical techniques. Combined withobservations and experimental analysesof behavior, both in clinical and labora­tory settings, these techniques providea large amount of data that link avariety of brain systems to specificaspects of behavior and experience.There can, therefore, be no lingeringdoubt but that brain, behavior, and ex­perience are related.

What then are the unresolved prob­lems that continue to occupy philoso­phers and thoughtful scientists? At base,I believe, is the issue that a materialbrain, open to public inspection, ap­pears to be involved in immaterialthoughts and experiences which are pri­vate. This duality is most readilyviewed as insurmountable, giving rise tothe view that dualism is an ontologicaldatum; or that brain and mind go theirseparate ways in parallel constructions,perhaps representing two aspects of acommon reality. The problem with sucha view is that there seems to be acontinual interaction between the mate­rial brain and immaterial thought andexperience which appears to take placein both directions: brain generatesthought; and experience becomes en­coded in the memory mechanisms ofthe brain.

Two different approaches have beentaken to deal with this apparent inter­action. One approach acknowledges theontological reality of the duality, theother denies such reality by calling at­tention to the identities which mustcharacterize the dual domains, thusmaking it unnecessary that they inter-

. act at all.My proposal is that all of these

approaches to the nature Of the' rela­tionship between mind and brain havesome merit. A scientific approach tophilosophical issues is to break themdown into more manageable components

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which are amenable to research. Brainresearch can be direct (in vivo) or in­direct (in vitro), as biological chemistsare wont to call these forms of inves­tigation. In the case of the mind/brainrelationship, psychophysical, psycho­physiological and neuropsychological ob­servation and experiment in the clinicand laboratory provide the direct ap­proach; computer simulations and opti­cal image processing devices take theplace of test tube (in vitro) research.

The results of such an approachyield what might be called a pluralisticmonism. As so often in human endeav­ors, approxima~ions to truth displaywhat seem, at first, paradoxical char­acteristics. But, as is detailed below,' apluralistic monism has the advantage oftaking seriously each of the majorphilosophical approaches which nave beentaken and, I believe, at the same timemeeting the criticisms which have beenlevied against them. After all, despitethese negative assaults, each of theseapproaches, as well as several modifi­cations and amalgams thereof, haveshown remarkable staying power. Thismakes one wonder whether, perhaps,each approach has some real merit andhas captured part of the truth, butthat it becomes flawed when it tries toencompass the entire spectrum of prob­lems which composes the mind/brainrelationship.

It is the fact that the mind/brainrelationship involves a spectrum ofproblems which will be the keystone ofthe analysis set out in the currentessay. As noted, scientists go abouttheir business by breaking down globallyconceived issues into more tractableproblems. As more and more of thepartial solutions come into focus, thelarger issue itself becomes resolved,provided the partial solutions are re­flected back to the issue which

Karl Pribram

spawned the research in the first place.The danger of the scientific approachis that it may result in an extreme re­ductionism or, alternatively, in instru­mentalism. Reduction, as has so oftenbeen said, leads the scientist to learnmore and more about less and less inorder to secure a limited certaintybased on technical competence. Instru­mentalism leads him to eschew anysearch for validity in theoretical con­struction, and to fail to project theresults of his observations and experi­ments onto the frame of reference(often held implicitly) which generatedthose observations and experiments inthe first place.

But reductionism and instrumental­ism are not necessary premises of thescientific approach. A constructionalrealism is not only philosophically tena­ble but is 'the way of life' of mostscientists. Scientists test conjecturesand hypotheses which are based on ob­servation and experiment and stated insuch a way as to be subject to refuta­tion by further observation and experi­ment. Karl Popper (J 968) has rightlypointed out that much of scientificprocedure is based on such 'conjectureand refutation.' What he failed toemphasize is that this procedure leadsto the construction of ever more com­prehensive views of what we interpretas reality. Maxwell and I have sharedthe judgment that the constructiveaspects of scientific. procedure oughtnot to be minimized.

By contrast, a purely philosophicalapproach relies largely on conceptualanalysis as expressed in language. Andas Quine (J 960) and others have pointedout, linguistic expressions rarely conveyidentical meanings to different audi­ences. A case in point is the meaningof 'mind' in various European languages.

In all languages, most approa'ches

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to the mind/brain relationship treat asingle unity "mind" as different from asingle unity "brain." But of course wenow know that the brain is composedof different systems: Some of these arein fairly direct connection with thesense organs and striped muscles of thebody, and are thus fitted to carry outextrinsic, extensional, extrapersonalaspects of relationships between theorganism and its environment. Othersystems are characterized by theirchemical specificities and connectionswith visceral and endocrine structureswhich makes them ideally suited to themore intensional aspects of mentalprocesses. Still other brain systemsfeature intrinsic connections amongbrain systems without any direct con­nections with more peripheral bodystructures. The results of clinical ob­servation and of experiment have shownthese systems to be involved with avariety of cognitive processes.

The concept "mind" also is com­posed of a variety of attentional, (i.e.,current), memory (retrospective), andintentional (prospective) processes. InEnglish the concept is derived from"minding," as Gilbert Ryle has pointedout, and originates from the Teutonic"mynden," a root common to both mindand memory. But in some continentallanguages the meaning of "mind" isambiguous. The French "esprit" and theGerman "Geist" are closer in meaningto the English "spirit" than to mind. By'spirit" is meant the relationship ofmental processes to more cosmic or­derings, which include the human socialorder. The German "Geisteswissenschaft"therefore usually has been translated as"human science." Thus in the verylanguages which have been the mostinfluential in shaping our approach tothe mind/brain issue, the distinction be­tween mind and spirit is not self-

Karl Pribram

evident, while in English, discussions ofthe relationship between brain and mindrarely focus on social or cosmic issues.No wonder there has been occasion forconfusion.

I shall proceed here with the Eng­lish distincti9n between mind and spirit,and take up the major approaches thathave been taken to the mind/brain re­lationship. In each case I shall attemptto show the range of data to which theparticular approach applies. As willbecome evident, identity, duality, plu­rality, and even monism have theirplace in a comprehensive theory re­garding mind/brain relationships.

Hierarch~ Reci rocal Causation,and ind Brain Identity:

The computer and its programshave provided a useful metaphor in theanalysis of the mind/brain issue inwhich the distinction between brain,mind and spirit can be seen as similarto the distinction between machine(hardware), low-level programs (codes)and high-level programs (software).Low-level programs, such as machinelanguages and assemblers, are not onlyidiosyncratic to particular types ofcomputer hardware, but there is alsoconsiderable similarity between thelogic of these languages and the logicaloperations of the machines in whichthey function. On the other hand, highlevel languages such as Fortran, Algoland Pascal are more universal in theirapplication, and there is less obvioussimilarity between their implicit logicand the logic of machines. At thehighest level, languages such as English,with which I am addressing my com­puter in order to use it as a wordprocessor, the relation between itslogos (word, concept, logic) and that ofthe machine is still more remote. How-

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ever, English relates me to a sizablechunk of the human social order.

Understanding, how computer pro­grams are composed helps to tear apartsome of the issues involved in the"identity" 'approach to the mind/brainrelationship: Because our introspectionsprovide no apparent connection to thefunctions of the neural tissues thatcomprise the brain, it has not beeneasy to understand what theorists aretalking about when they claim thatmental and brain processes are identi­cal. Now, because of the computer pro­gram analogy, we can suggest thatwhat is common to mental operationsand the brain "wetware" in which theoperation is realized is some orderwhich remains invariant across transfo(­mat ions. The terms "information" (inthe brain and cognitive sciences) and"structure" (in linguistics and in music)are the most commonly used to de­scribe such identities across transfor­mations.

Order invariance across transfor­mations is not limited to computersand computer programming. In music werecognize a Beethoven sonata or Berliozsymphony irrespective of whether it ispresented to us as a score on sheets ofpaper, in a live concert, over our highfidelity music system, and even in ourautomobiles when distorted and muffledby noise and poor reproduction. The in­formation (form within), the structure(arrangement) is recognizable in manyrealizations. The materials which makethe realizations possible differ consider­ably from each other, but these dif­ferences are not part of the essentialproperty of the music form. In thissense, the identity approach to themind/brain relationship, despite itsrealism, partakes of Platonic universals,i.e., ideal orderings which are liable tobecome flawed in their realization.

Karl Pribram

In the construction of computerlanguages we gain insight into how in­formation or structure is realized in amachine. The essence of biological aswell as of co-nputational hierarchies isthat higher levels of organization takecontrol over, and are controlled by,lower levels. Such reciprocal causationis ubiquitous in living systems: thusthe level of tissue carbon dioxide notonly controls the neural respiratorymechanism but is controlled by it aswell. Discovered originally as a regula­tory principle which maintains a con­stant environment, reciprocal causationwas termed "home9stasis." Researchfrom the past few decades has estab­lished that such feedback mechanismsare ubiquitous, involving sensory, motorand all sorts of central processes.

Equally important, programming al­lows us to analyze the evolution oflinguistic tools which relate the variouslevels of programming languages. Digi­tal computers with binary logic requirea low level language <Coded in thenumerals a or T) which sets a series ofbinary switches. At the next level,switch settings can be ;:;rouped so thatthe binary digits (bits) are convertedinto a more complex ·code consisting ofbytes, each of which is given an alpha­numerical label. Thus, for example, theswitch setting 00 1 becomes 1, thesetting a1a becomes 2, and the setting100 becomes 4. Given that 000 is 0,there are now 8 possible combinations,each of which is an octal byte.

This process is repeated at thenext level by grouping bytes into rec­ognizable words. Thus, J734 becomesADD; 2051 becomes SKIP and so forth.In high-level languages, grtfufs of wordsare integrated into woe routineswhich can be executed by one com­mand.

It is likely that some type of hier-

archical integration is involved in re­lating mental processes to the brain.Sensory mechanisms transduce patternsof physical energy into patterns ofneural energy. Because sensory recep­tors such as the retina and the cochleaoperate in an analog rather than a dig­ital mode, the transduction is consider­ably more complex than the. codingoperations described above. Nonetheless,much of neurophysiological investigationis concerned with discovering the corre­spondence between the pattern ofphysical input and the pattern of neuralresponse. As more complex inputs areconsidered, the issue becomes one ofcomparing the physically determinedpatterns with subjective experience(psychophysics), and of recording pat­terns of response of sensory stations inthe brain.

These comparisons have shown thata number of transformations occur be­tween sensory receptor surfaces and thebrain cortex. These transformations areexpressed mathematically as transferfunctions. When the transfer functionsreflect identical patterns at the inputand output of a sensory station, thepatterns are considered to be geometri­cally isomorphic, i.e., of the same formWhen the transfer functions ·are linear(i.e., superposable and invertible, re­versible), the patterns are considered tobe secondarily or algebraically isomor­phic. Thus, as in the case of computerprogramming, levels of processing arerecognized, each cascade in the levelproducing transformations which pro­gressively alter the form of the patternwhile maintaining intact some basicorder, information and structure.

In short, holding the identity"position" with regard to the mind/brain issue involves specifying what itis that remains identical. Unless some­thing remains constant across all of the

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Karl Pribram

coding operations which convert Englishto binary machine code. and back toEnglish, my word processing procedureswould not work. Identity implies recip­rocal stepwise causation among struc­tural levels. Contrary to the usuallyheld philosophical position, identity doesnot necessarily mean geometrical oreven algebraic isomorphism'. Transfor­mations, coding operations, occur, whichhierarchically relate levels of complexi­ty with one another. A level is definedby the fact that its description, i.e., itscode, is in some non-trivial sense moreefficient (i.e., requires less work, lessexpenditure of energy) than use of thecode of the components which composeit. In the case of the word processorthe coding is arbitrary, and the arbi­trariness is stored on a diskette andcopyrighted. In the case of the mind/brain relationship the nature of thecoding operations is more universal andthe efforts of a century and a half ofpsychophysical, neuropsychological andcognitive research have provided knowl­edge concerning at least some of thecoding operations involved.

Nominalizations, Propositionsand Mind/Brain Dualism:

In the beginning was the word, butthe word was put to peculiarly humanuses only when propositional utterancesbecame the currency of communication.The great apes are clearly able (seereViews by Pribram, 1971; Rumbaugh,1980) to make signs and symbols whichstand for concepts (Jogos=word, con­cept). Apes can string several suchsigns together and arrange symbolshierarchically. They also. occasionallymake propositions, but this mode ofcommunication is severely restrictedwhen compared to that of children ofthe same age (ana using the same

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modality of communication, Le.,Ameslan, American Sign Language;Bellugi & Klima, 1972).

A proposition uses words as nounsand predicates, and is made up of asubject verb and object. It is as naturalfor humans to make· propositions as forrose bushes to grow thorns. Propositionsgrow from holophrases which symbolizeexisting situations, both external andinternal. Also natural is the tendencyfor the holophrases to become nominal­ized, i.e., to make objects of the situ­ations symbolized. Thus a symbol, whichoriginally referred to a process, tendslater to refer to an object,. The Hebrew.term "Yahweh" demonstrates such anevolution: initially the word stood for"being," then a being who finally be­came the all encompassing being, God.More currently, physiologists discover afunction of a gland, such as the pitui­tary, by injecting it into animals. Thisfunction is first named but the namequickly becomes reified, and biochem­ists go to work to find the "substance"which has been named. 'And, of course,they are often successful. Nuclearphysics proceeds in a similar fashion,although only traces of the named"particles" are discovered.

Because nominalization objectifiesthe holophrastic utterance, its processaspect is either lost (as in Yahweh), orprocess becomes symbolized by anotherword, a predicate. It is then but a stepto a true proposition. which portraysthe process more fully: a subject actingon an object. The human disposition todichotomize subject and object is, Ibelieve, the primordium which, whenapplied to the mind/brain issue, givesrise to dualism.

Philosophers and thinkers, especial­ly Brentano, von Uexkuell, and Husserl,have emphasized this relationship be­tween human linguistic capability which

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Karl Pribram

derives from reflective awareness, andhuman "intentionality." As noted, how­ever, some confusion has arisen becausethe German language in which thesephilosophers worked, does not clearlydistinguish between mind and spirit.Thus, when translated into English,spiritual overtones creep in where noneare intended in the German original.

As Brentano (1874) clearly stated,humans can tell the difference betweenthat which is observed and the ob­server who is making the observation:i.e., between object and subject. Thisduality is enhanced by the fact that,when the subject is an introspector, hisintrospections are private until and un­less made public by way of verbal orinstrumental behavior. The privacy issueis emphasized by those holding thedualistic "position" to the extent thatthese philosophers claim for privacy auniqueness which is unparallelled any­where else in the search for knowledge.As a behavioral scientist, I cannotsupport this claim. I see little differ­ence in kind between the work involvedin breaching the privacy of the atomand breaching the privacy of a fellowhuman being. Both are. fraught with un­certainty and incompleteness.

A related and, for me, a morecogent issue, is the primacy of phe­nomenal experience. All I know is whatI have experienced. But again, primacyextends to all knowledge and is thus

. not limited to problems in the behav­ioral and brain sciences. Nonetheless,because of primacy, my private experi­ence is somehow special and at thelevel of the ordinary sensory world asdescribed in Euclidian, Cartesian andNewtonian concepts, I find mind/braindualism to be useful.

Take for example the computermetaphor discussed above. There iscertainly a non-trivial difference be-

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tween computer hardware and programsoftware. The hardware is material, thesoftware, as noted, is composed ofcodes which maintain some structuralidentity of information which is inde­pendent of any specific material reali­zation. A similar situation describesthe mind/brain duality: the wetware ofthe brain is material; mental processesare composed of codes which maintainsome structural identity of information,which is independent of any specificmaterial realization. This property ofmind to maintain constancies acrosstransformations is, I believe, responsiblefor reification, the natural tendency toobjectify what was initially experiencedas a process.

This analysis makes clear onceagain the reciprocal causation whichobtains in hierarchically organized bio­logical systems. The functions of cer­tain brain systems (those which, whenthey malfunction, produce the syndromeof "neglect") are responsible for, andcausally determine, reflective conscious­ness, intentionality, etc. At the sametime, the behavior generated under thecontrol of reflective consciousness,determines, causes controlling inputsto be provided to the very brain sys­tems upon which reflective conscious­ness depends.

Process, Predication,and Mind/Brain Interactions:

Recently Popper arid Eccles (1977)and Sperry (1969, 1976) have addressedthe problem of modes of interactionbetween mental process and brain. Allpossible combinations of interactionhave been suggested. Popper ha's evenadded a "third world" of culture as amedium for interaction. Essentially, thepossibilities are: (I) that mental proc­esses are engendered by the brain (a

Karl Pribram

view held by most brain and behavioralscientists and by Popped; (2) that someencompassing order in the universeorganizes brain processes and is thusresponsible for the spiritual nature ofman (a view held by Eastern philoso­phers and many Western philosophers ofan existential and/or phenomenalisticpersuasion); (3) that interaction is atwo-way street with the street remain­ing unspecified (Sperry) or specified ascuI ture (Popper).

Behavioral scientists understandthat mental processes are inferred fromobservations of the behavior of organ­isms, as well as from introspection.And behavior is organized by both· theorganism (for complex behaviors, espe­cially his brain) and his environment.Organisms learn from their environmentand act on their environment frommemory (both genetic and experiential).Behavioral scientists are therefore sup­portive of two-way mind/brain inter­action almost by definition. And asnoted, reciprocal causation, the feed­back process, is the commonplace ofhierarchically organized biological proc­esses. What is at issue for biologistsare the mechanisms whereby the inter­actions can occur. Philosophers, on theother hand, worry that interaction im­plies some fundamental and unbridge­able between the interacting parts:mental and material. As we have seen,coding operations, informational struc­t.ures, provide the bridge and thus blurthe distinction between interaction andreciprocal causation between structural­ly identical orders of events.

Human natural language is themediator between introspection and ob­served behavior. A child experiences aflying object. His mother names theobject a bird. Later other flying ob­jects are experienced and mother ex­plains that these are airplanes, and

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helps make the distinction between theexperiences of bird and plane. (In myfamily the course of distinguishing wentin this direction only for earlier chil­dren. Later children first learned whatplanes were. and then became aware ofbirds.) Naming has coordinated the per­ceptions, inspections and introspectionsof the child with those of his mother--- and through this coordination he canshare his introspection with that partof the human community which speaksthe same language. Sharing is inter­active.

Cognitive Commoditiesand Instrumental Dualism:

Sharing is also accomplished byother language-like human communi­cative activities. Mathematics, music,rituals and similar "cognitive com­modities" (Pribram, Sharafat &Beekman, 1983) are the instrumentswhich make possible the interactionsamong human minds and therefore, viasensory input, among human brains.What is special about the mind/brainrelationship is the primacy of experi­ence, and the fantastic. generative andorganizing capabilities of the humanbrain. It is these characteristics whichgive the duality approach and its deriv­atives a special appeal.

Dualism also derives strength fromthe hierarchical arrangement of thesearch for knowledge (Pribram, 1965).Beginning as it does with personal ex­perience, the search can proceedthrough consensual (among the senses)validation to interpersonal and intra­and intercultural validation via theinstrument of language, as noted above.The social sciences and humanities fol­low this course toward knowing. Ofcourse, analytical procedures can beinstituted at every step, and usually

Karl Pribram

are. Overall, however, there is a look­ing upward in a hierarchy of disciplineswhose object is to know together, tobecome aware, conscious (con-scient,sharing knowledge with another ct.,O.E.D.

On the other hand, it is possible tobegin to dissect one's experience,usually first-hand. Here the instrumentof search is direct observation and ex­periment. The bird falls and we feel itsfeathers and perhaps later perform ex­periments in an attempt to understand(stand under) what makes possible itsflight. The plane lands and we examineits instruments, and if possible, dis­assemble them and the rest of theplane in order to understand whatmakes it fly. We dissect bodies andfind brains. We dissect brains and findtissues. We dissect tissues and findcells, and then membranes, and mole­cules and atoms and hadrons and lep­tons and quarks. But at this level ofinvestigation it becomes clear that thetools· of observation and the mathe­matical operations necessary to sharethe experiences of dissection are cri ti­cally involved. We are again dependenton cognitive commodities, on language,on mathematics, on mental processesmuch as in the social sciences and thehumanities. Dissection, the reductiveapproach, has led full circle to themental processes which not only in­augurated the process of reductiveanalysis but also have been everpresent, though in less easily recog­nized form, at every step of analyticalunderstanding. Overall, the reductiveapproach is nonetheless a downwardprocess in a hierarchy of disciplinesand it is the rare scientist who turnshis face upwards to look once more atthe problems which seized him wherehe started.

To summarize: Mind/brain duality

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stems from the same roots which gen­erate linguistic behavior. Dualism alsorooted in the hierarchical structure ofthe organization of the means, theinstruments by which we know and con­struct our sciences. Looking upward(from the experiential center) in thishierarchy, one encounters the social(often referred to as the "soft") sci­ences and the humanities. In theseendeavors language is the instrumentwhich makes possible the sharing ofexperiences. Looking downward (fromthe experiential center), one encountersthe natural (often referred to as the"hard") sciences. In these endeavorsdirect observation and reproducible ex­periment are the instruments whichmake possible the sharing of under­standing. However, dualism does notexplain the actual processes of vali­dation and investigation where there isa continual transaction between lan­guage and observation.

Dualism also fails at the limits ofinquiry: at the infinitesimal, obser­vations become critically dependent onthe instruments chosen by the observer,so that questions arise as to whatmight constitute an "observable"(Wigner, 1969). Furthermore, the re­lationships between these observationsare framed in mathematical terms andit is primarily these mathematicaltheories (and not observables) which areshared. Since observations per se andmathematical communications are men­tal rather than immaterial, a pan­psychism follows readily. However,since neither the observations nor themathematical theories can be in­stantiated, i.e., realized in the absenceof material instruments, a pervasivematerialism becomes equally plausible.

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Karl Pribram

Materialism, Phenomenalism,and MUltiple Aspects:

Critical philosophers, especiallythose of the Vienna Circle, attemptedto solve this mental/material dilemmaby resorting to the fact that our knowl­edge is described linguistically and thatit is constituted by the descriptions,which are either mental or material,not by that which is being described.This "multiple aspects approach" ap­pears to eat its cake and have it aswell: a material/mental duality is af­firmed as a linguistic necessity, butidentity is rescued· in that the linguis­tic descriptions are about somethingelse, which of course is identical toitself. What is lacking in this formula­tion is any specification of the natureof that "something else."

As noted, materialists can readilyargue that actualization, embodiment,realization of any experience is com­pletely dependent on the materialnature of the physical universe, in­cluding the brain. Thus the somethingelse must in essence be material if itis to be real.

As also noted, phenomenalists canmake an equally persuasive claim: allthat is real to us is our experience,including our experience of the physicalworld. The something else must there­fore be mental.

A third alternative exists and thisalterl)ative claims that the somethingelse is neutral with respect to thematerial/mental duality. Most criticalphilosophers, (e.g., Herbert Feigl, 1960;Bertrand Russell, 1948) espoused thisform of "neutral monism." As mostmaterialists and phenomenalists will in­sist, however, the issue remains un­resolved until the neutral essence isidentified. Despite these limitations,the approach taken by critical philoso-

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phers has helped enormously to en­compass and clarify the mind/brainissue and to identify many of the re­maining problems.

The Construction ofMUltiple Realizations:

The deficiencies of the multipleaspects approach to the mind/brainissue can in part be resolved. Resolu­tion comes with a fundamental modifi­cation: The many guises which realitytakes are not just different linguisticforms. Rather, the different guises aredifferent realizations~ As noted, reali­zations are experienced physical actual­izations, material embodiments, ofinformational structures. The reali­zations are constructions, often re­quiring work to accomplish.

In this formulation, as in that ofthe critical philosophers, the importantaspects of mind/brain dualism are in­corporated. In fact, dualism can readilybe expanded into a pluralism in whichwhat is mental and what is physicalneed not be specified. Such specifi­cation often getS in the way, as forinstance whet;' it is necessary to dealwith measures on information, as incommunication systems and with com­puter programs. Are such measures asbits and bytes to be regarded as phys­ical and public, or mental and private?Is a program patentable or only subjectto copyright? The most appropriatereaction to such questions is impatience:somehow such questions seem to bewide of the mark, probing neither theessence of the mind/brain issue nor thepractical matter at hand. The difficultyis inherent in attempting to specify in­formational structure as either mentalor physical.

The difficulty is highlighted by theold question: Is the pursuit of mathe-

Karl Pribram

matics invention or discovery? If in­vention, why does the. mathematics sooften presage a physical discoverywhich fits? If discovery, what mentallode is being mined? Obviously, mathe­matics partakes of both invention anddiscovery, and pertains to an infor­mational structure which is potentialand neutral to the mind/brain duality.In short, mathematics is the sciencewhich deals with structure.

Energy and Entropy: (InformationalStructureras the Neutral Potential:

Another attractive feature of themultiple realization approach is that itallows the specification of information­al structure as the something elsewhich is neutral to the mental/materialduality. That something else must bepotential to becoming realized. Inphysics, such potentials are defined interms of the actual or possible workwhich is necessary for realization tooccur and is labeled Energy. Thus,multiple realizations imply a neutralmonism in which the neutral essence,the potential for realization, is energy.And, as stated in th(' second law ofthermodynamics, energy has en tropicproperties, it has structure.

Heisenberg (1969) developed amatrix approach to understanding theorganization of energy potentials. Cur­rently this approach is used in s-matrix,bootstrap theories of quantum andnuclear physics by Henry Stapp andGeoffry Chew (Chew, 1966; Stapp,1965). These investigators have pointedout that measures of energy potentialare related to measures of location inspacetime by way of a Fourier trans­form. The Fourier theorem states thatany pattern of organization can beanalyzed into, and represented by, aseries of regular wave forms of dif-

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ferent amplitudes and frequencies.These regular wave forms can in turnbe superimposed, convolved, with oneanother by way of the inverse Fouriertransform to obtain the original space­time configuration. The reason for usingthis mathematical transformation isthat it allows patterns to be correlatedwith one another. Thus the Fouriertransform of a set of patterns whichhave been correlated displays an .organ­ization different from that which isdisplayed after the inverse' Fouriertransform has again converted it tospacetime.

In terms of the proposition putforward by Stapp and Chew, this meansthat the organization of energy poten­tials is considerably different from thespacetime organization of our ordinaryperceptions which can be expressed inEuclidean, Cartesian and Newtonianterms. David Bohm (1971, 1973) hasidentified these non-classical organi­zations of energy potentials as "im­plicate," i.e., enfolded, and has usedthe hologram as an example of suchenfolded orders. Dennis Gabor (1946,t948), the inventor of the hologram,based his discovery on the fact thatone can store interference patterns ofwave forms produced by the reflectionor refraction of light from an objecton a photographic film and reconstruetfrom such a film the image of the ob­ject. The description of the enfoldedorganization of the stored potential forreconstruction is related to the un­folded spacetime description of theobject by a Fourier transform.

The Fourier theorem has alsoplayed an important role in recent dis­coveries in the brain sciences. In thelate 1960's several groups of investi­gators found that they could explaintheir findings in visual research byframing their results in terms of

Karl Pribram

"spatial frequency." This term wascoined by Fergus CampbeJJ and JohnRobson (1968) of Cambridge Universitywhen they discovered unexpected regu­larities in their data. Responses togratings of different widths andspacings adapted not only to the par­ticular grating shown but also at otherdata points. These additional adapta­tions could be understood by describingthe gratings as composed of regularwave forms with a given frequency.The frequency was determined by thespacings of the grating, and thus theterm "spatial frequency." Spatial andtemporal frequencies are related ofcourse: Scanning by a steadily movingbeam would describe the grating's tem­poral frequency. Physicists thereforeuse the term "wave number" to denotethis form of description of patterns.

In the late 1950's, David Hubel andThorsten Wiesel (1959, 1968) had dis­covered that single· ceUs in the visualcortex responded best when the visualsystem was stimulated with lines at acertain orientation. In the early andmid 1970's, Daniel PoUen (PoUen, Lee& Taylor, 1971; PoUen & Taylor, 1974)noted that when such lines were driftedacross the visual field, the response ofthe ceJJ was not uniform but describeda wave form similar to that which de­scribed the gratings used by FergusCampbell. CampbeU (1974) meanwhileshowed that the responses of singleceUs in the visual cortex also adaptedto the harmonics of the gratings whichwere presented, much as did the organ­ism as a whole. FinaUy, RusseU andKaren DeValois (1980) and their col­laborators demonstrated that the re­sponse of these visual cortical ceUs isonly poorly described by the orientationof a line, while it is accurately de­scribed in terms of the spatial fre­quency of a grating; i.e., the ceU is

25

tuned to a spatial frequency range ofapproximately one-half to one octave.Further, these investigators showedthat when checkerboards and plaidswere used to stimulate the visual sys­tem, the ceUs responded maximaUy tothe Fourier transform of the spacetimepatterns, as determined by computerdisplay, and that the ceUs were essen­tiaUy unresponsive to the orientation ofthe lines which composed the checker­boards and plaids. In short, it appearsthat the visual system performs aFourier transform on the image pro­duced by the lens of the eye.

What this means is that the opti-.cal image is decomposed into itsFourier components: regular wave formsof different frequencies and amplitudes.Cells in the visual system respond toone or another of these componentsand thus, in aggregate, comprise anoptical image processing filter whichhas characteristics similar to the photo­graphic filter comprising a hologram,from which images can be recon­structed by implementing the inversetransform.

There are, however, important dif­ferences between ordinary photographicholograms and the visual nervous sys­tem. Ordinary holograms are composedby a global Fourier transform whichdistributes the information contained ina spacetime image throughout thetransform domain. In the visual nervoussystem, distribution is limited anatomi­

.cally to the input cha·nneled to·a par­ticular cortical ceU. There are, how-ever, holographic techniques that usesimilar "patch" or multiplex construc­tions. BraceweU (1965) at Stanford Uni­versity pioneered these techniques inradioastronomy by stripping togetherthe holographic transformations of lim­ited sectors of the heavens as viewedby radiotelescope. When the inverse

Karl Pribram

transform is applied, spacetime imagesof the whole composite can be viewedin three dimensions.

Further, the transform which bestdescribes the process in the visual sys­tem is a Gabor, not Fourier. The Gabortransform (1948) is formed by placing aGaussian envelope on the otherwiseunlimited Fourier transformation. Thisis another way of stating that thetransformation is not global, and givesmathematical precision to the limitsinvolved.

Finally, the arrangement of thevisual channels and the cortical cellsis not haphazard with regard to oneanother. A clear retinotopic to corticalspatial arrangement· is maintained. Thusthe gross grain of the visual filter de­termines spacetime coordinates, whileits fine grain describes the Fouriercomponents.

What advantage is gained by thisfine grain holographic-like organization?Recall that in the transform domaincorrelations among patterns are readilyperformed. This is why the Fast FourierTransform (FFT) as performed by com­puter is such a powerful tool instatistical analysis and in computerizedtomography (CT scans). The brain is anexcellent correia tor by virtue of itsfine grain processing potential.

The dual of an enfolded fine grain(technically, the receptive field organi­zation) and a gross grain spacetimeorganization applies to other sense mo­dalities as well, although the experi­mental evidence is not as complete.Georg von Bekesy performed criticalstudies in the auditory and somastheticmodalities (1967), Walter Freeman inthe olfactory (1960), and Pribram et al.have shown that cells in the sensory­motor cortex are tuned to specificfrequencies of movement (1983). At thesame time, in all these sensory systems

26

the spatial organization of the receptorsurface is topographically representedin the gross grain arrangement of thecortical cells which receive the sensoryinput.

In summary, there is good evi­dence that there lies another class oforders behind the ordinary classicallevel of organization, which we per­ceive and which is described in termsof Eucledian and Newtonian views, andmapped in Cartesian space-time co­ordinates. This other class of orders isconstituted of fine-grain organizationswhich describe potentials which hadbeen poorly understood because of theradical changes which occur in thetransformational process of realization.When a potential is realized,' informa­tion becomes unfolded into its ordinaryspacetime appearance; in the otherdirection, the transformation enfoldsand distributes information as this isdone by the holographic process. Be­cause work is involved in transforming,descriptions in terms of energy aresuitable. Because the structure of in­formation is what is transformed, de­scriptions in terms of entropy (andnegentropy) are suitable. Thus completeunderstanding involves at least a dual:On the one hand, there are enfoldedorders manifested as energy potential;on the other, there are unfolded ordersmanifested in negentropic spacetime.

Conclusion and Prolegomenon

As this essay shows, research inthe information, physical and biologicalsciences has shed a good deal of lighton the relationship between brain, mindand spirit. Still, there is much to beaccomplished. Issues devolving aroundthe nature of feelings, the possibilityof free will in an apparently deter­mined frame, and the continued demon-

Karl Pribram

stration of creatIvIty among humanshave not yielded to the observationsrecorded above. It is therefore appro­priate to ask how a pluralistic neutralmonism can handle these issues. Mysuggestion is that the key to under­standing the problems associated withthese issues lies in unravelling thenature of the transformational processesinvolved in each specific realization ofpotential. Recall that in the pluralisticneutral monis'm, the single neutralentity is defined as energy potential,and plurality is attained through reali­zation in spacetime. The transforma­tions involved -in each realization,though they fall into the category"orthogonal," of which the Fourier isthe prototype, are in each individualinstance modified according to circum­stance. We traced such a modificationfrom Fourier to Gabor in some detailfor the visual system. Thus the classof orthogonal transformations which arelinear most probably are subject to allsorts of non-linear constraints.

These constraints are best con­ceived in terms of the degrees offreedom which they entail. Freedom,therefore, is relative to the constraintswhich define the transformation. Folkwisdom has proclaimed that freedomentails responsibility and Fritz Perlshas pointed out that this meansresponse-ability (1973). But according tothe views presented here, entailment isa . two-way street: thus response­ability entails freedom, i.e., it begetsfreedom. In turn, the ability to respondto a situation may involve altering theconstraints, the degrees of freedomwhich characterize it. In changing thedegrees of freedom which constrain asituation lies the roots of creativity,and of free will.

The "particular go" of how thischange in constraints is achieved is,

27

of course, different in each situation.But examples from music, linguisticsand invention can be detailed. A stringis plucked, then bowed, then a key­board is devised which removes themusician still further from the plucking.Instrumentation allows new combina­tions of sounds to be constructed.Instrumentation has increased the de­grees of freedom, the ability to re­spond to the opportunity entailed inthe fact that strings vibrate at certainfrequencies. In order for all this tooccur, the brain of the inventor of theinstruments had to correlate and cor­relate and correlate. In order to utilizethe instruments, the brain of themusician has to correlate and correlateand correlate. As noted, correlationsare the hallmark of processing in theenfolded order. Of course, correlationis not all that is involved, but cor­relation takes us a long way. Think fora moment of the usefulness of IBMpunched cards in the development ofcomputer programming. Essentially thecards furnished filters which weresuperimposed, correlating the informa­tion common fo all the cards in thestack. The Fourier filters describedabove are much more powerful, but theprinciple is the same.

Changes in the constraints whichguide linguistic communication, trans­portation, game playing, economicregulation all can be shown to display asimilar course of development. Cultureis composed of such cognitive com­modities which become realized in thematerial commodities of the market­place, only to become the forebears ofnovel cognitions.

But what about feelings and theinterpersonal relationships which theyreciprocally entail? The results of brainresearch over the past three decadeshave made substantial contributions to

,~

.T

--..,.,..---,-------------------,,.....,..---------------..--------------- ---

Karl Pribram

our knowledge of the mechanismsregulating pain and suffering, pleasureand wellbeing. Once again, a dualorganization of brain processes is in­volved: in this instance the fine grainenfolded and distributed processes areneurochemical, while the coarse grainunfolded spacetime processes remainfunctional anatomical systems. The re­sults of this research is, as yet, toorecent for much effective theory tohave emerged. However, it is of in­terest that Arnold Mandell (1973) hasdeveloped a Fourier model of severalbehavioral manifestations of feelingsbased on distributed neurochemicalinteractions.

I do not mean this outline to sug­gest that all problems are resolved oreven near resolution in regard, to howthe brain operates in manifestations offreedom, of feelings, of creativity.What I do propose is that relevantquestions can now be posed in experi­mentally operational and mathematicalterms so that resolution can proceed. I.have presented a philosophical stancewithin which these questions tan beframed, and have attempted to givesubstance to this stance and to relateit to other proposals by encompassingrather than by refuting them.

KARL H. PRIBRAM

References

Bekesey, G. von. Sensory inhibition. Princeton: Princeton University Press,1967.

Bellugi, U., [, Klima, E. The signs of language in child and chimpanzee. InT. Alloway, L. Kramer, [, P. Ploner (Eds.), Communication and affect: Acomparative approach. New York: Academic Press, 1972, pp. 67-96.

Bohm, D. Quantum theory as an indication of a new order in physics. Part A. Thedevelopment of new orders as shown through the history of physics. Founda­tions of Physics, 1971, ..!" pp. 359-381.

Bohm, D. Quantum theory as an indication of a new order in physics. Part B.Implicate and explicate order in physical law. Foundations of Physics,1973,1., pp. 139-168.

Bracewell, R. The Fourier Transform and its application. New York: McGraw-Hill,1965.

Brentano, F. [Psychology from an empirical standpoint.] (A. C. Rancurello, D.Terrell, [, L. McAlister, trans.). London: Routledge [, Kegan Paul, 1973.(Originally published, 1874.)

Campbell, F. W. The transmission of spatial information through the visualsystem. In. F. O. Schmidt [, F. G. Worden (Eds.), The Neurosciences ThirdStudy Program. Cambridge, Mass.: The MIT Press, 1974, pp. 95-103.

Campbell, F. W., [, Robson, J. G. Application of Fourier analysis to the visi-

28

Karl Pribram

bility of gratings. J. Physiol., 1968, 197, pp. 551-566.

Chew, G. S. The analytic s-matrix: A basis for nuclear democracy. NewW. A. Benjamin, 1966.

York:

DeValois,.R., & DeValois, K. Spatial vision. Ann. Rev. Psychol., 1980, ~, page309.

Feigl, H. Mind-Body, not a pseudoproblem. In S. Hook (Ed.), Dimensions of Mind.New York: Collier, 1960, pp. 33-44.

Freeman, W. J. Correlation of electrical act1vlty of prepyriform cortex andbehavior in c~t. J. Neurophysiol., 1960,32, pp. 111-131.

Gabor, D. Theory of communication. J. Inst. Elec. Engrs .. , 1946, ~, p. 429.

Gabor, D. A new microscopic principle. Nature, 1948, ~, pp. 777-778.

Heisenberg W. Physics and beyond. Munich: R. Piper, 1969.

Hubel, D. H. & Wiesel, T. N. Receptive fields of single neurons 1n the eat'sstriate cortex. J. Physiol., 1959, 148, pp. 574-591.

Hubel, D. H. & Wiesel, T. N. Receptive fields and functional architecture ofmonkey striate cortex. J. Physiol. 1968, 195, pp. 215-243.

James, W. Pragmatism --- A new name for some old ways of thinking. New York:Longmans Green & Co. ,1931. (1st edition, 1907.)

Mandell, A. J. (Ed.>. New concepts in neurotransmitter regulation. New York:Plenum Press, 1973, p. 316.

Maxwell. G. Scientific results and the mind-brain issue: Some afterthoughts. InG. C. Globus, G. Maxwell, & 1. Savodnik (Eds.), Consciousness and thebrain: A scienti fic and philosophical inquiry'. New York: Plenum Press,1976, pp. 329-358.

Miller, G. A., Galanter, E., & Pribram, K. H. Plans and the structure of be­havior. New York: Henry Holt, 1960.

Perls, F. S. The Gestalt approach and eye witness to therapy. Palo Alto: Sci­ence & Behavior Books, 1973.

Pollen, D. A., Lee, J. R., & Taylor, J. H. How does the striate cortex beginthe reconstruction of the visual world? Science, 1971, 173, pp. 44-77.

Pollen, D. A., & Taylor, J. H. The striate cortex and the spatial analysis of

29

Karl Pribram

visual space. !n The Neurosciences Study Program (Vol. III). Cambridge,Mass.: The MIT Press, 1974, pp. 239-247.

Popper, K. R. The logic of scientific discovery. New York: Harper & Row, 1968.

Popper, K. R., and Eccles, J. C. The self and its brain. Berlin: Springer­Verlag, 1977.

Pribram, K. H. Interrelations of psychology and the neurological disciplines.In S. Koch (Ed.), Psychology: A study ofa science. New York: McGraw-Hill,1962, pp. 119-157.

-----. Proposal for a structural pragmatism: Some neuropsychological consider­ations of problems in philosophy. In B. Wolman & E. Nagle (Eds.),Scientific psychology: Principles and approaches. New York: Basic Books,1965, pp. 426~459.

-----. The biology of the mind. Neurobehavioral foundations. In R. A. Gilgen(Ed.), Scientific psychology: Some perspectives. New York: Academic Press,1970, pp. 45-70.

The realization of mind. Synthese, 1971, 1l, pp. 313-322.

Operant behaviorism: Fad, fact-ory and fantasy? In H. Wheeler (Ed.),Beyond the punitive society --- operant conditioning: Social and politicalaspects. San Francisco: W. H. Freeman, 1973, pp. 101-112.

Problems concerning the structure of consciousness. In G. Globus,G. Maxwell, & 1. Savodnik (Eds.), Consciousness and brain: A scientificand philosophical inquiry. New York: Plenum Press, 1976, pp. 297-313. (a)

-----. Self-consciousness and intentionality. In G. E. Schwartz & D. Shapiro(Eds.), Consciousness and self-regulation: Advances in research. New York:Plenum Press, 1976, pp. 51-100. (b)

-----. Languages of the brain: Experimental paradoxes and principles in neuro­psychology. Monterey, Ca.: Brooks/Cole, 1977.

-----. Consciousness and neurophysiology. Federation Proceedings,pp. 2271-2274. (a)

1978,

.",

-----. Consciousness and unconscious processes: A neurophysiological and neuro­psychological analysis. In The unconscious: Its nature, functions, andmethods of study (vol. n, USSR: Metsniereva Pub. House, 1978, 'pp. 569­584. (b)

-----. The role of analogy ln transcending limits in the brain sciences.

30

Karl Pribram

Daedalus, 1980, 109, pp. 19-38.

-----. Behaviorism, phenomenology and holism in psychology: A scientific analy­sis. In R. Valle & R. von Eckartsberg (Eds.), The metaphors of conscious­ness. New York: Plenum Press, 1981, pp. 141-151. (a)

-----. Psychology as a science: Three fundamental approaches. In R. A. Kasschau& C. N. Cofer (Eds.), Psychology's second century, Houston Symposium 2.New York: Praeger, 1981, pp. 218-241. (b)

-----. Brain, cognitive commodities and the enfolded order. In K. E. Boulding& L. Sevesh (Eds.), The optimum utilization of knowledge: Making knowledgeserve human betterment. Boulder, Co.: Westview Press, 1983, pp. 29-40.

Pribram, K. H.,' Sharafat, A., & Beekman, G. J. Frequency encoding in motorsystems. In H. T. A. Whiting (Ed.), Human Motor Actions: Berstein reas-'sessed. North-Holland (in press), 1983.

Quine, W. V, Word and object. Cambridge, Mass.: The MIT Press, 1960.

Rumbaugh, D. Do apes use language? American Scientist. 1980, ~, pp. 49-61,

Russell, B. Human knowledge, its scope and limits. New York: Simon & Schuster,1948.

"l:"~, .'I ~ .

Sperry, R. W. A modified concept of consciousness. Psych. Rev.,pp. 532-636.

1969,

-----. Mental phenomena as causal determinants in brain function. InG. G. Globus, G. Maxwell, & I.Savodnik (Eds.), Consciousness and the brain.New York: Plenum Press, 1976, pp. 163-177.

Stapp, H. P. Space and time in s-matrix theory. Phys. Rev., 1965, 139B, pp. 257­270.

Wigner, E. P. Epistemology of quantum mechanics: Its appraisals and demands. InM. Grene (Ed.), The anatomy of knowledge. London: Routledge & Kegan Paul,1969, pp.

31