Teoria Cuantica y Neurociencias

8/20/2019 Teoria Cuantica y Neurociencias

1/19

Review

Quantum physics in neuroscience and psychology:

a neurophysical model of mind–brain interaction

Jeffrey M. Schwartz1, Henry P. Stapp2 and Mario Beauregard3,4,5,*

1UCLA Neuropsychiatric Institute, 760 Westwood Plaza, NPI Los Angeles, CA 90024-1759, USA2

Theoretical Physics Mailstop 5104/50A Lawrence Berkeley National Laboratory, University of California,

Berkeley, CA 94720-8162, USA3

Dé partement de Psychologie, Centre de Recherche en Neuropsychologie Expé rimentale et Cognition

(CERNEC), 4

Dé partement de Radiologie, and 5

Centre de Recherche en Sciences Neurologiques (CRSN),

Université de Montré al, C.P. 6128, succursale Centre-ille, Montré al, Qué bec H3C 3J7, Canada

Neuropsychological research on the neural basis of behaviour generally posits that brain mechanismswill ultimately suffice to explain all psychologically described phenomena. This assumption stems

from the idea that the brain is made up entirely of material particles and fields, and that all causalmechanisms relevant to neuroscience can therefore be formulated solely in terms of properties of these elements. Thus, terms having intrinsic mentalistic and/or experiential content (e.g. ‘feeling’,‘knowing’ and ‘effort’) are not included as primary causal factors. This theoretical restriction ismotivated primarily by ideas about the natural world that have been known to be fundamentallyincorrect for more than three-quarters of a century. Contemporary basic physical theory differsprofoundly from classic physics on the important matter of how the consciousness of human agentsenters into the structure of empirical phenomena. The new principles contradict the older idea thatlocal mechanical processes alone can account for the structure of all observed empirical data.Contemporary physical theory brings directly and irreducibly into the overall causal structure certain

psychologically described choices made by human agents about how they will act. This keydevelopment in basic physical theory is applicable to neuroscience, and it provides neuroscientistsand psychologists with an alternative conceptual framework for describing neural processes. Indeed,

owing to certain structural features of ion channels critical to synaptic function, contemporaryphysical theory must in principle be used when analysing human brain dynamics. The newframework, unlike its classic-physics-based predecessor, is erected directly upon, and is compatiblewith, the prevailing principles of physics. It is able to represent more adequately than classic conceptsthe neuroplastic mechanisms relevant to the growing number of empirical studies of the capacity of directed attention and mental effort to systematically alter brain function.

Keywords: mind; consciousness; brain; neuroscience; neuropsychology; quantum mechanics

The only acceptable point of view appears to be the one

that recognizes both sides of reality—the quantitative

and the qualitative, the physical and the psychical—as

compatible with each other, and can embrace themsimultaneously.

(Pauli 1955, p. 208)

1. INTRODUCTION

The introduction into neuroscience and neuro-psychology of the extensive use of functional brainimaging technology has revealed, at the empirical

level, an important causal role of directed attention incerebral functioning. The identification of brain areasinvolved in a wide variety of information processingfunctions concerning learning, memory and various

kinds of symbol manipulation has been the subject of extensive and intensive investigation (see Toga &

Mazziotta 2000). Neuroscientists consequently now

have a reasonably good working knowledge of the role

of a variety of brain areas in the processing of

complex information. But, valuable as these empiricalstudies are, they provide only the data for, not the

answer to, the critical question of the causal

relationship between the aspects of empirical studies

that are described in psychological terms and those

that are described in neurophysiological terms. In

most of the cases, investigators simply assume that

measurable-in-principle properties of the brain are

the only factors needed to explain eventually the

processing of the psychologically described infor-

mation that occurs in neuropsychological exper-

iments. This privileging of physically describable

brain mechanisms as the core, and indeed final,

explanatory vehicle for the processing of every kind of

psychologically described data, is the foundational

assumption of almost all contemporary biologically

based cognitive neuroscience.

Phil. Trans. R. Soc. B (2005) 360, 1309–1327

doi:10.1098/rstb.2004.1598

Published online 29 June 2005

*Author for correspondence ([email protected]).

Received 2 June 2004 Accepted 19 October 2004

1309 q 2005 The Royal Society


2/19

It is becoming increasingly clear, however, that thereis at least one type of information processing and

manipulation that does not readily lend itself toexplanations that assume that all final causes aresubsumed within brain, or more generally, centralnervous system mechanisms. The cases in question arethose in which the conscious act of wilfully altering themode by which experiential information is processeditself changes, in systematic ways, the cerebral mech-anisms used. There is a growing recognition of thetheoretical importance of applying experimental para-digms that use directed mental effort to producesystematic and predictable changes in brain function(e.g. Beauregard et al . 2001; Ochsner et al . 2002).These wilfully induced brain changes are generallyaccomplished through training in, and the applied useof, cognitive reattribution and the attentional re-contextualization of conscious experience. Further-more, an accelerating number of studies in theneuroimaging literature significantly support the thesis

that, again, with appropriate training and effort, peoplecan systematically alter neural circuitry associated witha variety of mental and physical states that are frankly

pathological (Schwartz et al . 1996; Schwartz 1998;Musso et al . 1999; Paquette et al . 2003). A recentreview of this and the related neurological literature hascoined the term ‘self-directed neuroplasticity’ to serveas a general description of the principle that focusedtraining and effort can systematically alter cerebralfunction in a predictable and potentially therapeuticmanner (Schwartz & Begley 2002).

From a theoretical perspective, perhaps the mostimportant aspect of this line of research is the empirical

support it provides for a new science-based way of conceptualizing the interface between mind/conscious-ness and brain. Until recently, virtually all attempts to

understand the functional activity of the brain havebeen based, at least implicitly, on some principles of classic physics that have been known to be fundamen-

tally false for three-quarters of a century. According tothe classic conception of the world, all causal connec-tions between observables are explainable in terms of mechanical interactions between material realities. Butthis restriction on modes of causation is not fullymaintained by the currently applied principles of physics, which consequently offer an alternative con-

ceptual foundation for the scientific description andmodelling of the causal structure of self-directedneuroplasticity.

The advantages for neuroscience and neuropsy-chology of using the conceptual framework of contemporary physics, as opposed to that of classic

physics, stem from five basic facts. First, terms suchas ‘feeling’, ‘knowing’ and ‘effort’, because they areintrinsically mentalistic and experiential, cannot be

described exclusively in terms of material structure.Second, to explain the observable properties of largephysical systems that depend sensitively upon thebehaviours of their atomic constituents, the founders

of contemporary physical theory were led to introduceexplicitly into the basic causal structure of physics certainimportant choices made by human beings about howthey will act. Third, within this altered conceptualframework these choices are described in mentalistic

(i.e. psychological) language. Fourth, terminology of precisely this kind is critically necessary for the designand execution of the experiments in which the datademonstrating the core phenomena of self-directedneuroplasticity are acquired and described. Fifth, theinjection of psychologically described choices on thepart of human agents into the causal theoreticalstructure can be achieved for experiments in neuro-science by applying the same mathematical rules thatwere developed to account for the structure of phenomena in the realm of atomic science.

The consequence of these facts is that twentiethcentury physics, in contrast to classic physics, provides arationally coherent pragmatic framework in which thepsychologically and neurophysiologically described

aspects of the neuroscience experiments mentionedabove are causally related to each other in mathemat-ically specified ways. Thus, contemporary physicsallows the data from the rapidly emerging field of self-directed neuroplasticity to be described and understoodin a way that is more rationally coherent, scientific anduseful than what is permitted by theories in which allcausation is required to be fundamentally mechanical.

To explicate the physics of the interface betweenmind/consciousness and the physical brain, we shall inthis article describe in detail how the quantummechanically based causal mechanisms work, andshow why it is necessary in principle to advance tothe quantum level to achieve an adequate theory of theneurophysiology of volitionally directed activity. Thereason, essentially, is that classic physics is an approxi-mation to the more accurate quantum theory, and thatthis classic approximation eliminates the causal efficacy of our conscious efforts that these experiments empiricallymanifest.

We shall also explain how certain structural featuresof ion conductance channels critical to synapticfunction entail that the classic approximation fails inprinciple to cover the dynamics of a human brain.Quantum dynamics must be used in principle. Further-more, once the transition to the quantum description ismade, the principles of quantum theory must, in orderto maintain rational consistency and coherency, beused to link the quantum physical description of thesubject’s brain to their stream of conscious experiences.The conscious choices by human agents therebybecome injected non-trivially into the causal interpret-ation of neuroscience and neuropsychology exper-iments. This caveat particularly applies to thoseexperimental paradigms in which human subjects arerequired to perform decision-making or attention-focusing tasks that require conscious effort.

2. PRACTICAL RAMIFICATIONS OF THE

ALTERED CONCEPT OF THE CAUSAL

STRUCTURE OF SELF-DIRECTED

NEUROPLASTICITY

Clarity is required about the sorts of neuroscientific

reasoning that remain coherent, given the structure of modern physics and, contrastingly, the types of asser-tion that can now be viewed as the residue of amaterialistic bias stemming from superseded physics.Entirely acceptable are correlational analyses about the

1310 J. M. Schwartz and others Model of mind–brain interaction

Phil. Trans. R. Soc. B (2005)


3/19

relationship between mentalistic data and neurophysio-logical mechanisms. Examining the qualitative and

quantitative aspects of brain function, and doingdetailed analyses of how they relate to the data of expe-rience, obtained through increasingly sophisticatedmeans of psychological investigation and subject self-report analysis (e.g. the entire September–October2003 issue of Journal of Consciousness Studies, volume10, number 9–10, is dedicated to these questions), arecompletely in line with fundamental physics. Theseactivities are the core of neuropsychological science.What is not justified is the presumption, either tacit orexplicit, that all aspects of experience examined andreported are necessarily causal consequences solely of brain mechanisms. The structure of contemporaryphysics entails no such conclusion. This is particularlyrelevant to data from first-person reports about active,wilfully directed attentional focus, and especially to datapertaining to which aspects of the stream of consciousawareness a subject chooses to focus on when making

self-directed efforts to modify and/or modulate thequality and beam of attention. In such cases, thestructure of orthodox quantum physics implies that

theinvestigator is not justified in assuming that thefocusof attention is determined wholly by brain mechanismsthat are in principle completely well-defined andmechanically determined. Conscious effort itself can,justifiably within science, be taken to be a primaryvariable whose complete causal origins may be untrace-able in principle, but whose causal efficacy in the physicalworld can be explained on the basis of the laws of physics.

As already emphasized, the cognitive frame in which

neuroscience research, including research on cerebralaspects of behaviour, is generally conducted containswithin it the assumption that brain mechanisms are in

principle fully sufficient to explain all of the observedphenomena. In the fields of functional neuroimaging,this has led to experimental paradigms that focus

primarily on changes in brain activation as primaryvariables used to explain whatever behavioural changesare observed—including ones understood as involvingessentially cognitive and emotional responses. As longas one is investigating phenomena that are mostlypassive in nature this may be fully justified. A person isshown a picture depicting an emotionally or perhaps a

sexually arousing scene. The relevant limbic and/ordiencephalic structures are activated. The investigatorgenerally concludes that the observed brain activationhas some intrinsic causal role in the emotional changesreported (or, perhaps, the hormonal correlates of thosechanges).

This method is all well and good, as far as it goes. Inaddition, from the experimental subject’s perspective, itis all quite passive—all that is reallyrequired on hisor her

part is to remain reasonably awake and alert or, moreprecisely, at least somewhat responsive to sensoryinputs. But when, as happens in a growing number of studies, the subject makes an active response aimed at

systematically altering the nature of the emotionalreaction—for example, by actively performing a cogni-tive reattribution—then the demand that the data beunderstood solely from the perspective of brain-basedcausal mechanism is a severe and counter-intuitive

constraint. It is noteworthy that this demand for anentirely brain-based causal mechanism is nullified, in

the quantum model developed here, by a specifiedquantum effect, which will be described in detail below.

Surmounting the limitations imposed by restricting

one’s ideas to the failed concepts of classic physicscan be especially important when one is investigatinghow to develop improved methods for altering theemotional and cerebral responses to significantlystressful external or internally generated stimuli. Anincorrect assignment of the causal roles of neurophys-iologically and mentalistically described variables canimpact negatively on a therapist’s selection of a courseof treatment, on a patient’s capacity to recover, and ona neuroscientist’s design of clinically relevant researchprogrammes.

In the analysis and development of clinical practicesinvolving psychological treatments and their biologicaleffects, the possession and use of a rationally coherentand physically allowable conception of the causalrelationship between mind and brain (or, if one prefers,mentalistic and neurophysiological variables) is critical.If one simply accepts the standard presumption that all

aspects of emotional response are passively determinedby neurobiological mechanisms, then the theoreticaldevelopment of genuinely effective self-directedpsychological strategies that produce real neurobio-logical changes can be impeded by the fact that one isusing a theory that excludes from the dynamics whatlogically can be, and in our model actually are, keycausal elements, namely our wilful choices.

The clinician’s attention is thus directed away fromwhat can be in many cases, at the level of actual

practice, a powerful determinant of action, namely thesubject’s psychologically (i.e. mentalistically) framedcommitment to act or think in specific ways. Thetherapist tends to becomes locked into the view that the psychological treatment of ailments caused by neurobio-logical impairments is not a realistic goal.

There is already a wealth of data arguing against thisview. For instance, work in the 1990s on patients withobsessive compulsive disorder demonstrated significantchanges in caudate nucleus metabolism and thefunctional relationships of the orbitofrontal cortex– striatum–thalamus circuitry in patients who respondedto a psychological treatment using cognitive reframing

and attentional refocusing as key aspects of thetherapeutic intervention (for review, see Schwartz &Begley 2002). More recently, work by Beauregard andcolleagues (Paquette et al . 2003) has demonstratedsystematic changes in the dorsolateral prefrontal cortexand parahippocampal gyrus after cognitive-behaviouraltherapy for phobia of spiders, with brain changes signi-ficantly related to both objective measurements andsubjective reports of fear and aversion. There are now

numerous reports on the effects of self-directedregulation of emotional response, via cognitive refram-ing and attentional re-contextualization mechanisms,on cerebral function (e.g. Schwartz et al . 1996;

Beauregard et al . 2001; Ochsner et al . 2002; Lévesqueet al . 2003; Paquette et al . 2003;).The brain area generally activated in all the studies

done so far on the self-directed regulation of emotionalresponse is the prefrontal cortex, a cortical region also

Model of mind–brain interaction J. M. Schwartz and others 1311



4/19

activated in studies of cerebral correlates of wilfulmental activity, particularly those investigating self-

initiated action and the act of attending to one’s ownactions (Spence & Frith 1999; Schwartz & Begley2002). There is, however, one aspect of wilful mentalactivity that seems particularly critical to emotionalself-regulation, and that seems to be the critical factorin its effective application—the factor of focuseddispassionate self-observation that, in a rapidly growingnumber of clinical psychology studies, has come to becalled ‘mindfulness’ or ‘mindful awareness’ (Segal et al .2002).

The mental act of clear-minded introspection andobservation, variously known as mindfulness, mindfulawareness, bare attention, the impartial spectator, etc.,is a well-described psychological phenomenon with along and distinguished history in the description of human mental states (Nyanaponika 2000). The mostsystematic and extensive exposition is in the canonical

texts of classic Buddhism preserved in the Pali language,a dialect of Sanskrit. Because of the critical importanceof this type of close attentiveness in the practice of Buddhist meditation, some of its most refined descrip-tions in English are in texts concerned with meditativepractice (although it is of critical importance to realizethat the mindful mental state does not require anyspecific meditative practice to acquire, and is certainlynot in any sense a ‘trance-like’ state).

One particularly well-established description, usingthe name ‘bare attention’, is as follows:

Bare Attention is the clear and single-minded aware-

ness of what actually happens to us and in us at the

successive moments of perception. It is called ‘Bare’

because it attends just to the bare facts of a perceptionas presented either through the five physical senses or

through the mind.without reacting to them.

(Nyanaponika 1973, p. 30)

Perhaps the essential characteristic of mindfulobservation is that you are just watching, observingall facts, both inner and outer, very calmly, clearly andclosely. To sustain this attentional perspective overtime, especially during stressful events, invariablyrequires the conscious application of effort.

A working hypothesis for ongoing investigation inhuman neurophysiology, based on a significant body of

preliminary data, is that the mental action of mindfulawareness specifically modulates the activity of theprefrontal cortex. Because of the well-established roleof this cortical area in the planning and wilful selectionof self-initiated responses (Spence & Frith 1999;Schwartz & Begley 2002), the capacity of mindfulawareness, and by implication all emotional self-regulating strategies, to specifically modulate activityin this critical brain region has tremendous impli-cations for the fields of mental health and related areas.

It might be claimed that the designs and executionsof successful clinical practices (and of informativeneuropsychological experiments) that depend on the

idea of the causal efficacy of conscious effort, and whichfit so well into the quantum conceptualization thatactually explains the causal efficacy of these efforts,could just as well be carried out within the conceptualframework in which the causal efficacy of wilful effort is

an illusion, or is something very different from what itintuitively seems to be. But such a claim is not easy to

defend. Simple models that are consistent with basicintuition and lead directly to experimentally demon-strable conclusions are better than philosophically

intricate ones that lead to the same conclusions. Of course, if it could be argued that the simple modelcould not be true because it violates the basic principlesof physics whereas the more intricate one obeys them,then there might be reasonable grounds for question ordispute. But in the present case the reverse is true: it isthe simple model that is built on the basic laws of physics and it is the arcane and philosophically difficultmodel, in which our basic human intuition concerningthe efficacy of mental effort is denied as not being whatit seems to be, which contradicts the laws of physics.

The major theoretical issue we address in this articleis the failure of classic models of neurobiological actionto provide a scientifically adequate account for all of themechanisms that are operating when human beings use

self-directed strategies for the purpose of modulatingemotional responses and their cerebral correlates.Specifically, the assumption that all aspects of mental

activity and emotional life are ultimately explicablesolely in terms of micro-local deterministic brainactivity, with no superposed effects of mental effort,produces a theoretical structure that both fails to meetpractical scientific needs, and also fails to accord withthe causal structure of modern physics.

In the alternative approach the role played by themind, when one is observing and modulating one’s ownemotional states, is an intrinsically active and physicallyefficacious process in which mental action is affecting

brain activity in a way concordant with the laws of physics. A culturally relevant way of framing thischange is to say that contemporary physics imbuesthe venerable and therapeutically useful term‘psychodynamic’ with rigorous neurophysical efficacy.

This new theory of the mind–brain connection is

supportive of clinical practice. Belief in the efficacy of mental effort in emotional self-regulation is neededto subjectively access the phenomena (e.g. belief in theefficacy of effort is required to sustain mindfulnessduring stressful events). Moreover, a conceptualframework in which psychologically described effortshave effects is needed to explain to patients what they

are supposed to do when directing their inner resourcesto the challenging task of modifying emotional andcerebral responses. Clinical success is jeopardized by abelief on the part of either therapists or patients thattheir mental effort is an illusion or a misconception.

It takes effort for people to achieve therapeuticresults. That is because it requires a redirection of thebrain’s resources away from lower level limbicresponses and toward higher level prefrontal func-

tions—and this does not happen passively. Rather, itrequires, in actual practice, both wilful training anddirected mental effort. It is semantically inconsistentand clinically counterproductive to insist that these

kinds of brain changes be viewed as being solely anintra-cerebral ‘the physical brain changing itself’ typeof action. That is because practical aspects of theactivity of mind essential to the identification, acti-vation, application and use of directed mental effort are




5/19

not describable solely in terms of material brainmechanisms. The core phenomena necessary for thescientific description of self-directed neuroplasticity are

processes that cannot be elaborated solely in terms of

classic models of physics.Furthermore, as we will see in detail in the following

sections of this article, orthodox concepts of contem-porary physics are ideally suited to a rational and

practically useful understanding of the action of mindfulself-observation on brain function. Classic models of

physics, which view all action in the physical world asbeing ultimately the result of the movements of material

particles, are now seriously out of date, and no longer

need be seen as providing the unique, or the best,scientifically well-grounded paradigm for investigatingthe interface between mind/consciousness and brain.

When people practice self-directed activities for thepurpose of systematically altering patterns of cerebral

activation they are attending to their mental and

emotional experiences, not merely their limbic or

hypothalamic brain mechanisms. And although noscientifically oriented person denies that those brainmechanisms play a critical role in generating thoseexperiences, precisely what the person is training him-

or herself to do is to wilfully change how those brainmechanisms operate—and to do that requires attend-

ing to mental experience per se. It is, in fact, the basic

thesis of self-directed neuroplasticity research that theway in which a person directs their attention (e.g. mind-

fully or unmindfully) will affect both the experientialstate of the person and the state of his/her brain. Theexistence of this close connection between mental effort

and brain activity flows naturally out of the dynamic

principles of contemporary physics, but is, within theframework of classic physics, a difficult problem that

philosophers of the mind have been intensively engagedwith, particularly for the past 50 years. The core

question is whether the solution to this problem lieswholly in the eventual development of a more sophis-

ticated philosophy that is closely aligned with theclassic known-to-be-fundamentally-false conception of

nature, or whether the profound twentieth centurydevelopment in physics, that assigns a subtle but

essential causal role to human consciousness, canusefully inform our understanding of the effects

of human consciousness in neuropsychological exper-

iments that appear to exhibit the causally efficaciouspresence of such effects.

To appreciate the major conceptual changes made in

basic physical theory during the twentieth century, one

must know about certain key features of the oldertheory.

3. CLASSIC PHYSICS

Classic physics is a theory of nature that originated withthe work of Isaac Newton in the seventeenth centuryand was advanced by the contributions of James Clerk

Maxwell and Albert Einstein. Newton based his theoryon the work of Johannes Kepler, who found that the

planets appeared to move in accordance with a simple

mathematical law, and in ways wholly determined bytheir spatial relationships to other objects. Those

motions were apparently independent of our humanobservations of them.

Newton effectively assumed that all physical objectswere made of tiny miniaturized versions of the planets,which, like the planets, moved in accordance with

simple mathematical laws, independently of whetherwe observed them or not. He found that he could thenexplain the motions of the planets and also the motionsof large terrestrial objects and systems, such as cannonballs, falling apples and the tides, by assuming thatevery tiny planet-like particle in the solar systemattracted every other one with a force inverselyproportional to the square of the distance betweenthem.

This force was an instantaneous action at a distance: itacted instantaneously, no matter how far the particleswere apart. This feature troubled Newton. He wrote toa friend ‘That one body should act upon anotherthrough the vacuum, without the mediation of anythingelse, by and through which their action and force maybe conveyed from one to another, is to me so great anabsurdity that I believe no man, who has in philoso-phical matters a competent faculty of thinking, can ever

fall into it’ (Newton 1687, p. 634). Although Newton’sphilosophical persuasion on this point is clear, henevertheless formulated his universal law of gravitywithout specifying how it was mediated.

Albert Einstein, building on the ideas of Maxwell,discovered a suitable mediating agent, a distortion of the structure of space–time itself. Einstein’s contri-butions made classic physics into what is called a local theory: there is no action at a distance. All influences aretransmitted essentially by contact interactions between

tiny neighbouring mathematically described ‘entities’,and no influence propagates faster than the speed of light.

Classic physics is, moreover, deterministic: theinteractions are such that the state of the physicalworld at any time is completely determined by the state

at any earlier time. Consequently, according to classictheory, the complete history of the physical world for all time is mechanically fixed by contact interactions

between tiny component parts, together with the initialcondition of the primordial universe.

This result means that, according to classic physics, you are a mechanical automaton: your every physical

action was predetermined before you were born solelyby mechanical interactions between tiny mindlessentities. Your mental aspects are causally redundant :everything you do is completely determined bymechanical conditions alone, without any mention of your thoughts, ideas, feelings or intentions. Yourintuitive feeling that your conscious intentions make adifference in what you do is, according to the principlesof classic physics, a false and misleading illusion.

There are two possible ways within classic physics tounderstand this total incapacity of your mental side(i.e. your stream of conscious thoughts and feelings) to

make any difference in what you do. The first way is to

consider your thoughts, ideas and feelings to beepiphenomenal by-products of the activity of yourbrain. Your mental side is then a causally impotentsideshow that is produced , or caused , by your brain, butthat produces no reciprocal action back upon your brain.




6/19

The second way is to contend that each of yourconscious experiences—each of your thoughts, ideas,or feelings—is the very same thing as some pattern of motion of various tiny parts of your brain.

4. PROBLEMS WITH CLASSIC PHYSICS

William James (1890, p. 138) argued against the firstpossibility, epiphenomenal consciousness, by claimingthat ‘The particulars of the distribution of consciousness, sofar as we know them, points to its being efficacious.’ Henoted that consciousness seems to be ‘an organ,superadded to the other organs which maintain theanimal in its struggle for existence; and the presump-tion of course is that it helps him in some way in thisstruggle, just as they do. But it cannot help him withoutbeing in some way efficacious and influencing thecourse of his bodily history.’ James said that the studydescribed in his book ‘will show us that consciousness isat all times primarily a selecting agency.’ It is present

when choices must be made between different possiblecourses of action. He further mentioned that ‘It is tomy mind quite inconceivable that consciousness shouldhave nothing to do with a business to which it sofaithfully attends’ (1890, p. 136).

If mental processes and consciousness have no effectupon the physical world, then what keeps a person’smental world aligned with their physicalsituation? Whatkeeps their pleasures in general alignment with actionsthat benefit them, and pains in general correspondencewith things that damage them, if felt pleasures and painshave no effect at all upon their actions?

These liabilities of the notion of epiphenomenal

mind and consciousness lead many thinkers to turn tothe alternative possibility that a person’s mind andstream of consciousness is the very same thing as someactivity in their brain: mind and consciousness are‘emergent properties’ of brains.

A huge philosophical literature has developedarguing for and against this idea. The primaryargument against this ‘emergent-identity theory’ pos-ition, within a classic physics framework, is that in classic

physics the full description of nature is in terms of numbers assigned to tiny space–time regions, and thereappears to be no way to understand or explain how toget from such a restricted conceptual structure, which

involves such a small part of the world of experience, tothe whole. How and why should that extremely limitedconceptual structure (which arose basically fromidealizing, by miniaturization, certain features of observed planetary motions) suffice to explain thetotality of experience, with its pains, sorrows, hopes,colours, smells and moral judgements? Why, given theknown failure of classic physics at the fundamental level ,should that richly endowed whole be explainable interms of such a narrowly restricted part?

The core ideas of the arguments in favour of anidentity-emergent theory of mind and consciousnessare illustrated by Roger Sperry’s (1992) example of a

‘wheel’. A wheel obviously does something: it iscausally efficacious; it carries the cart. It is also anemergent property: there is no mention of ‘wheelness’ inthe formulation of the laws of physics and ‘wheelness’did not exist in the early universe; ‘wheelness’ emerges

only under certain special conditions. And the macro-scopic wheel exercises ‘top-down’ control of its tiny

parts. All these properties are perfectly in line withclassic physics, and with the idea that ‘a wheel is,precisely, a structure constructed out of its tiny atomic

parts’. So why not suppose mind and consciousness tobe, like ‘wheelness’, emergent properties of theirclassically conceived tiny physical parts?

The reason that mind and consciousness are notanalogous to ‘wheelness’, within the context of classicphysics, is that the properties that characterize‘wheelness’ are properties that are entailed , within theconceptual framework of classic physics, by propertiesspecified in classic physics, whereas the properties thatcharacterize conscious mental processes, namely thevarious ways these processes feel, are not entailed withinthe conceptual structure provided by classic physics,but by the properties specified by classic physics.

That is the huge difference-in-principle that dis-tinguishes mind and consciousness from things that,

according to classic physics, are constructible out of theparticles that are postulated to exist by classic physics.

Given the state of motion of each of the tiny physical

parts of a wheel, as it is conceived of in classic physics,the properties that characterize the wheel (e.g. itsroundness, radius, centre point, rate of rotation, etc.)are specified within the conceptual framework providedby the principles of classic physics, which specify onlygeometric-type properties such as changing locationsand shapes of conglomerations of particles andnumbers assigned to points in space. But given thestate of motion of each tiny part of the brain, as it isconceived of in classic physics, the properties that

characterize the stream of consciousness (the painful-ness of the pain, the feeling of the anguish, or of thesorrow, or of the joy) are not specified, within theconceptual framework provided by the principles of classic physics. Thus it is possible, within that classicphysics framework, to strip away those feelings without

disturbing the physical descriptions of the motions of the tiny parts. One can, within the conceptual frame-work of classic physics, take away the consciousnesswhile leaving intact the properties that enter into thattheoretical construct, namely the locations andmotions of the tiny physical parts of the brain and itsphysical environment. But one cannot, within the

conceptual framework provided by classic physics,take away the physical characteristics that define the‘wheelness’ of a wheel without affecting the locationsand motions of the tiny physical parts of the wheel.

Because one can, within the conceptual frameworkprovided by classic physics, strip away mind andconsciousness without affecting the physical behaviour,one cannot rationally claim, within that framework, thatmind and consciousness are the causes of the physical

behaviour, or are causally efficacious in the physicalworld. Thus the ‘identity theory’ or ‘emergent prop-erty’ strategy fails in its attempt to make mind andconsciousness efficacious, insofar as one remains

strictly within the conceptual framework provided byclassic physics. Moreover, the whole endeavour to basebrain theory on classic physics is undermined by thefact that classic theory is unable to account forbehavioural properties (such as electrical and thermal




7/19

conductivity, and elasticity, etc.) that depend sensi-tively upon the behaviour of the atomic, molecular andionic constituents of a system, and brains are certainlysystems of this kind, as will be discussed in detail later.

Although classic physics is unable to account forobservable properties that depend sensitively on thebehaviours of atoms, molecules and ions, the classictheory is an approximation to a more accurate theory,called quantum theory, which is able to account forthese observable macroscopic properties. But if classicphysics is unable to account for the moderatelycomplex behavioural properties of most other largesystems, then how can it be expected to account for theexquisitely complex behavioural properties of thinkingbrains?

5. THE QUANTUM APPROACH

Early in the twentieth century scientists discoveredempirically that the principles of classic physics could

not be correct. Moreover, those principles were wrongin ways that no minor tinkering could ever fix. The basic principles of classic physics were thus replaced by newbasic principles that account uniformly for all thesuccesses of the older classic theory and for all thedata that are incompatible with the classic principles.

The key philosophical and scientific achievement of the founders of quantum theory was to forge arationally coherent and practicable linkage betweenthe two kinds of description that jointly comprise thefoundation of science. Descriptions of the first kind areaccounts of psychologically experienced empiricalfindings, expressed in a language that allows us to

communicate to our colleagues what we have done andwhat we have learned. Descriptions of the second kindare specifications of physical properties, which areexpressed by assigning mathematical properties tospace–time points and formulating laws that determinehow these properties evolve over the course of time.Bohr, Heisenberg, Pauli and the other inventors of quantum theory discovered a useful way to connectthese two kinds of description by causal laws. Their

seminal discovery was extended by John von Neumannfrom the domain of atomic science to the realm of neuroscience and, in particular, to the problem of understanding and describing the causal connections

between the minds and the brains of human beings.In order to achieve this result, the whole concept of what science is was turned inside out. The core idea of classic physics was to describe the ‘world out there’,with no reference to ‘our thoughts in here’. But the coreidea of quantum mechanics is to describe both our activities as knowledge-seeking and knowledge-acquiring

agents, and the knowledge that we thereby acquire. Thus,quantum theory involves, essentially, what is ‘in here’,not just what is ‘out there’.

This philosophical shift arises from the explicit recognition by quantum physicists that science isabout what we can know. It is fine to have a beautiful

and elegant mathematical theory about a really existing physical world out there that meets various intellectuallysatisfying criteria. But the essential demand of science isthat the theoretical constructs be tied to the experi-ences of the human scientists who devise ways of testing

the theory and of the human engineers and technicianswho both participate in these tests and eventually put

the theory to work. Thus, the structure of a properphysical theory must involve not only the part describ-ing the behaviour of the not-directly experienced

theoretically postulated entities, expressed in someappropriate symbolic language, but also a part describ-ing the human experiences that are pertinent to thesetests and applications, expressed in the language thatwe actually use to describe such experiences toourselves and to each other. And the theory mustspecify the connection between these two differentlydescribed and differently conceived parts of scientificpractice.

Classic physics meets this final requirement in atrivial way. The relevant experiences of the humanparticipants are taken to be direct apprehensions of thegross properties of large objects composed of hugenumbers of their tiny atomic-scale parts. Theseapprehensions (of, for example, the perceived location

and motion of a falling apple or the position of apointer on a measuring device) were taken to be passive:they had no effect on the behaviours of the systems

being studied. But the physicists who were examiningthe behaviours of systems that depend sensitively uponthe behaviours of their tiny atomic-scale componentsfound themselves forced to introduce a less trivialtheoretical arrangement. In the new scheme the humanagents are no longer passive observers. They areconsidered to be active agents or participants.

The participation of the agent continues to beimportant even when the only features of the physicallydescribed world being observed are large-scale properties of

measuring devices. The sensitivity of the behaviour of thedevices to the behaviour of some tiny atomic-scale

particles propagates first to the devices and then tothe observers in such a way that the choice made by anobserver about what sort of knowledge to seek canprofoundly affect the knowledge that can ever be

received either by that observer himself or by any otherobserver with whom he can communicate. Thus thechoice made by the observer about how he or she will actat a macroscopic level has, at the practical level, aprofoundeffect on the physicalsystem being acted upon.

That conclusion is not surprising. How one acts on asystem would, in general, be expected to affect it. Nor is

it shocking that the effect of the agent’s actions uponthe system being probed is specified by the quantummechanical rules. But the essential point not to beoverlooked is that the logical structure of the basicphysical theory has become fundamentally trans-formed. The agent’s choice about how to act hasbeen introduced into the scientific description at a basiclevel and in a way that specifies, mathematically, howhis or her choice about how to act affects the physical

system being acted upon.The structure of quantum mechanics is such that,

although the effect upon the observed system of theagent’s choice about how to act is mathematically

specified, the manner in which this choice itself isdetermined is not specified. This means that, in thetreatment of experimental data, the choices made byhuman agents must be treated as freely chosen inputvariables, rather than as mechanical consequences of




8/19

any known laws of nature. Quantum theory therebyconverts science’s concept of us from that of amechanical automaton, whose conscious choices are

mere cogs in a gigantic mechanical machine, to that of agents whose conscious free choices affect the physi-

cally described world in a way specified by the theory.The approximation that reduces quantum theory to

classic physics completely eliminates the importantelement of conscious free choice. Hence, from a physicspoint of view, trying to understand the connection

between mind/consciousness and brain by going to theclassic approximation is absurd: it amounts to trying to

understand something in an approximation thateliminates the effect we are trying to study.

This original formulation of quantum theory wascreated primarily at an institute in Copenhagen

directed by Niels Bohr and is called ‘the Copenhageninterpretation’. Owing to the strangeness of the proper-

ties of nature entailed by the new mathematics, theCopenhagen strategy was to refrain from making any

ordinary sort of ontological claims, but instead to takean essentially pragmatic stance. Thus, the theory wasformulated basically as a set of practical rules for how

scientists should go about the tasks of acquiring,manipulating and using knowledge. Claims about

‘what the world out there is really like’ were consideredto lie beyond science.

This change in perspective is captured by Heisen-berg’s famous statement:

The conception of the objective reality of the elemen-

tary particles has thus evaporated not into the cloud

of some obscure new reality concept, but into

the transparent clarity of a mathematics that represents

no longer the behavior of the particle but rather ourknowledge of this behavior.

(Heisenberg 1958, p. 100).

A closely connected change is encapsulated in NielsBohr’s dictum that ‘in the great drama of existence we

ourselves are both actors and spectators’ (Bohr 1963,p. 15; 1958, p. 81). The emphasis here is on ‘actors’: inclassic physics we were mere spectators. The key idea is

more concretely expressed in statements such as:

The freedom of experimentation, presupposed in

classic physics, is of course retained and corresponds

to the free choice of experimental arrangement for

which the mathematical structure of the quantummechanical formalism offers the appropriate latitude.

(Bohr 1958, p. 73)

Copenhagen quantum theory is about how the

choices made by conscious human agents affect theknowledge they can and do acquire about the physically

described systems upon which these agents act. Inorder to achieve this re-conceptualization of physics the

Copenhagen formulation separates the physical uni-verse into two parts, which are described in twodifferent languages. One part is the observing human

agent plus its measuring devices. This extended ‘agent’,

which includes the devices, is described in mentalterms—in terms of our instructions to colleagues abouthow to set up the devices and our reports of what we

then ‘see’, or otherwise consciously experience. Theother part of nature is the system that the agent is acting

upon. That part is described in physical terms—interms of mathematical properties assigned to tiny

space–time regions. Thus, Copenhagen quantumtheory brings ‘doing science’ into science. In particular,it brings a crucial part of doing science, namely our

choices about how we will probe nature, directly intothe causal structure. It specifies the effects of theseprobing actions upon the systems being probed.

This approach works very well in practice. However,the body and brain of the human agent, and also theirdevices, are composed of atomic constituents. Hence acomplete theory ought to be able to describe thesesystems in physical terms.

The great mathematician and logician John vonNeumannformulated quantum theory in a rigorous waythat allows the bodies and brains of the agents, alongwith their measuring devices, to be shifted into thephysically described world. This shift is carried out in aseries of steps, each of which moves more of what theCopenhagen approach took to be the psychologically

described ‘observing system’ into the physicallydescribed ‘observed system’. At each step the crucialact of choosing or deciding between possible optional

observing actions remains undetermined by the physicalobserved system. This act of choosing is always ascribedto the observing agent. In the end all that is left of thisagent is what von Neumann calls his ‘abstract ego’. It isdescribed in psychological terms, and is, in practice, thestream of consciousness of the agent.

At each step the direct effect of the conscious act isupon the part of the physically described world that isclosest to the psychologically described world. Thismeans that, in the end, the causal effect of the agent’s

mental action is on their own brain, or some significantpart of their brain.von Neumann makes the logical structure of

quantum theory very clear by identifying two verydifferent processes, which he calls process 1 andprocess 2 (von Neumann 1955, p. 418). Process 2 is

the analogue in quantum theory of the process in classicphysics that takes the state of a system at one time to itsstate at a later time. This process 2, like its classicanalogue, is local and deterministic. However, process 2by itself is not the whole story: it generates a host of ‘physical worlds’, most of which do not agree with ourhuman experience. For example, if process 2 were,

from the time of the big bang, the only process innature, then the quantum state (centre point) of themoon would represent a structure smeared out over alarge part of the sky, and each human body–brainwould likewise be represented by a structure smearedout continuously over a huge region. Process 2generates a cloud of possible worlds, instead of the oneworld we actually experience.

This huge disparity between properties generated by

the ‘mechanical’ process 2 and the properties weactually observe is resolved by invoking process 1.

Any physical theory must, in order to be complete,specify how the elements of the theory are connected to

human experience. In classic physics this connection ispart of a metaphysical superstructure: it is not part of thedynamic process. But in quantum theory a linkage of the mathematically described physical state to humanexperiences is contained in the mathematically




9/19

specified dynamic. This connection is not passive. It isnot a mere witnessing of a physical feature of nature.

Instead, it injects into the physical state of the system being acted upon specific properties that depend upon choices made

by the agent .Quantum theory is built upon the practical concept

of intentional actions by agents. Each such action is a preparation that is expected or intended to producean experiential response or feedback. For example, ascientist might act to place a Geiger counter near aradioactive source and expect to see the counter either‘fire’ during a certain time-interval or not ‘fire’ duringthat interval.The experienced response, ‘Yes’ or ‘No’,tothe question, ‘Does the counter fire during the specifiedinterval?’, specifies one bit of information. Quantumtheory is thus an information-based theory built uponthe preparative actions of information-seeking agents.

Probing actions of this kind are not only performedby scientists. Every healthy and alert infant is con-tinually engaged in making wilful efforts that produce

experiential feedbacks and he or she soon begins toform expectations about what sorts of feedbacks areprobable to follow from some particular kind of effort.

Thus, both empirical science and normal human lifeare based on paired realities of this action–responsekind, and our physical and psychological theories areboth basically attempting to understand these linkedrealities within a rational conceptual framework.

The basic building blocks of quantum theory are,then, a set of intentional actions by agents and for eachsuch action an associated collection of possible ‘Yes’feedbacks, which are the possible responses that theagent can judge to be in conformity to the criteria

associated with that intentional act. For example, theagent is assumed to be able to make the judgement‘Yes’ the Geiger counter clicked, or ‘No’ the Geiger

counter did not click. Science would be difficult topursue if scientists could make no such judgementsabout what they are experiencing.

All known physical theories involve idealizations of one kind or another. In quantum theory the mainidealization is not that every object is made up of miniature planet-like objects. It is rather that there areagents that perform intentional acts each of which canresult in feedback that may or may not conform to acertain criterion associated with that act. One piece of

information is introduced into the world in which thatagent lives, according to whether or not the feedbackconforms to that criterion. The answer places the agenton one or the other of two alternative possible branchesof the course of world history.

These remarks reveal the enormous difference

between classic physics and quantum physics. Inclassic physics the elemental ingredients are tinyinvisible bits of matter that are idealized miniaturized

versions of the planets that we see in the heavens andthat move in ways unaffected by our scrutiny, whereasin quantum physics the elemental ingredients areintentional preparative actions by agents, the feedbacks

arising from these actions and the effects of theseactions upon the physically described states of theprobed systems.

This radical restructuring of the form of physicaltheory grew out of a seminal discovery by Heisenberg.

That discovery was that in order to get a satisfactoryquantum generalization of a classic theory one mustreplace various numbers in the classic theory byactions (operators). A key difference betweennumbers and actions is that if A and B are twoactions then AB represents the action obtained byperforming the action A upon the action B. If A andB are two different actions then generally AB isdifferent from BA: the order in which actions areperformed matters. But for numbers the order doesnot matter: ABZBA.

The difference between quantum physics and itsclassic approximation resides in the fact that in thequantum case certain differences AB–BA are pro-portional to a number measured by Max Planck in

1900, and called Planck’s constant. Setting thosedifferences to zero gives the classic approximation.Thus quantum theory is closely connected to classicphysics, but is incompatible with it, because certainnon-zero quantities must be replaced by zero to obtainthe classic approximation.

The intentional actions of agents are representedmathematically in Heisenberg’s space of actions.A description of how it operates follows.

Each intentional action depends, of course, on theintention of the agent and upon the state of the system

upon which this action acts. Each of these two aspects of nature is represented within Heisenberg’s space of actions by an action. The idea that a ‘state’ should berepresented by an ‘action’ may sound odd, butHeisenberg’s key idea was to replace what classicphysics took to be a ‘being’ with a ‘doing’. We shalldenote the action (or operator) that represents the statebeing acted upon by the symbol S .

An intentional act is an action that is intended toproduce a feedback of a certain conceived or imaginedkind. Of course, no intentional act is certain: one’sintentions may not be fulfilled. Hence the intentionalaction merely puts into play a process that will leadeither to a confirmatory feedback ‘Yes’, the intention isrealized, or to the result ‘No’, the ‘Yes’ response did notoccur.

The effect of this intentional mental act is rep-resented mathematically by an equation that is one of the key components of quantum theory. This equationrepresents, within quantum mathematics, the effect of process 1 action upon the quantum state S of thesystem being acted upon. The equation is:

S /S 0ZPSPC ðI KP ÞS ðI KP Þ:

This formula exhibits the important fact that thisprocess 1 action changes the state S of the system beingacted upon into a new state S 0, which is a sum of twoparts.

The first part, PSP , represents in physical terms, thepossibility in which the experiential feedback called‘Yes’ appears and the second part, (I KP )S (I KP ),represents the alternative possibility ‘No’, this ‘Yes’

feedback does not appear. Thus, an effect of theprobing action is injected into the mathematicaldescription of the physical system being acted upon.

The operator P is important. The action representedby P , acting both on the right and on the left of S , is the




10/19

action of eliminating from the state S all parts of S except the ‘Yes’ part. That particular retained part isdetermined by the choice made by the agent. Thesymbol I is the unit operator, which is essentiallymultiplication by the number 1, and the action of (I KP ), acting both on the right and on the left of S is,analogously, to eliminate from S all parts of S exceptthe ‘No’ parts.

Notice that process 1 produces the sum of the twoalternative possible feedbacks, not just one or theother. Since the feedback must either be ‘Yes’ or‘NoZNot-Yes’, one might think that process 1, whichkeeps both the ‘Yes’ and the ‘No’ possibilities, would donothing. But that is not correct. This is a key point. Itcan be made absolutely clear by noticing that S can be

written as a sum of four parts, only two of which survivethe process 1 action:

S ZPSPC ðI KP ÞS ðI KP ÞCPS ðI KP ÞC ðI KP ÞSP:

This formula is a strict identity. The dedicated reader

can quickly verify it by collecting the contributions of the four occurring terms PSP , PS , SP and S , andverifying that all terms but S cancel out. This identityshows that the state S is a sum of four parts, two of whichare eliminated by process 1.

But this means that process 1 has a non-trivial effect

upon the state being acted upon: it eliminates the twoterms that correspond neither to the appearance of a‘Yes’ feedback nor to the failure of the ‘Yes’ feedback toappear.

This result is the first key point : quantum theory has aspecific causal process, process 1, which produces anon-trivial effect of an agent’s choice upon the physical

description of the system being examined. (‘Nature’will eventually choose between ‘Yes’ and ‘No’, but wefocus here on the prior process 1, the agent’s choice.Nature’s subsequent choice we shall call process 3.)

(a) Free choicesThe second key point is this: the agent’s choices are

‘free choices’, in the specific sense specified below.Orthodox quantum theory is formulated in a

realistic and practical way. It is structured around theactivities of human agents, who are considered able tofreely elect to probe nature in any one of many possible

ways. Bohr emphasized the freedom of the exper-imenters in passages such as the one already quotedearlier, or the similar:

The foundation of the description of the experimental

conditions as well as our freedom to choose them is

fully retained.(Bohr 1958, p. 90)

This freedom of choice stems from the fact that inthe original Copenhagen formulation of quantumtheory the human experimenter is considered tostand outside the system to which the quantum lawsare applied. Those quantum laws are the only precise

laws of nature recognized by that theory. Thus,according to the Copenhagen philosophy, there are no presently known laws that govern the choices made by theagent/experimenter/observer about how the observedsystem is to be probed. This choice is thus, in this very

specific sense, a ‘free choice’. The von Neumanngeneralization leaves this freedom intact. The choicesattributed to von Neumann’s ‘abstract ego’ are no morelimited by the known rules of quantum theory than arethe choices made by Bohr’s experimenter.

( b) Nerve terminals, ion channels and the need to use quantum theory in the study of the

mind–brain connection

Neuroscientists studying the connection of mindand consciousness to physical processes in the brainoften assume that a conception of nature based onclassic physics will eventually turn out to be adequate.That assumption would have been reasonable duringthe nineteenth century. But now, in the twenty-firstcentury, it is rationally untenable. Quantum theorymust be used in principle because the behaviour of thebrain depends sensitively upon atomic, molecular andionic processes, and these processes in the brain ofteninvolve large quantum effects.

To study quantum effects in brains within anorthodox (i.e. Copenhagen or von Neumann) quan-tum theory one must use the von Neumann formu-lation. This is because Copenhagen quantum theory isformulated in a way that leaves out the quantumdynamics of the human observer’s body and brain. Butvon Neumann quantum theory takes the physicalsystem S upon which the crucial process 1 acts to beprecisely the brain of the agent, or some part of it. Thusprocess 1 describes here an interaction between aperson’s stream of consciousness, described in menta-listic terms, and an activity in their brain, described inphysical terms.

A key question is the quantitative magnitude of quantum effects in the brain. They must be large inorder for deviations from classic physics to play anysignificant role. To examine this quantitative questionwe consider the quantum dynamics of nerve terminals.

Nerve terminals are essential connecting linksbetween nerve cells. The general way they work isreasonably well understood. When an action potentialtravelling along a nerve fibre reaches a nerve terminal, a

host of ion channels open. Calcium ions enter throughthese channels into the interior of the terminal. Theseions migrate from the channel exits to release sites onvesicles containing neurotransmitter molecules. A

triggering effect of the calcium ions causes thesecontents to be dumped into the synaptic cleft thatseparates this terminal from a neighbouring neuron,and these neurotransmitter molecules influence thetendencies of that neighbouring neuron to ‘fire’.

At their narrowest points, calcium ion channels areless than a nanometre in diameter (Cataldi et al . 2002).This extreme smallness of the opening in the calciumion channels has profound quantum mechanicalimplications. The narrowness of the channel restrictsthe lateral spatial dimension. Consequently, the lateralvelocity is forced by the quantum uncertainty principle tobecome large. This causes the quantum cloud of

possibilities associated with the calcium ion to fan out over an increasing area as it moves away from the tinychannel to the target region where the ion will beabsorbed as a whole, or not absorbed at all, on somesmall triggering site.




11/19

This spreading of this ion wave packet means that theion may or may not be absorbed on the small triggering

site. Accordingly, the contents of the vesicle may ormay not be released. Consequently, the quantum stateof the brain has a part in which the neurotransmitter isreleased and a part in which the neurotransmitter is notreleased. This quantum splitting occurs at every one of the trillions of nerve terminals. This means that thequantum state of the brain splits into a vast host of classically conceived possibilities, one for each possiblecombination of the release-or-no-release options ateach of the nerve terminals. In fact, because of uncertainties on timings and locations, what is gener-ated by the physical processes in the brain will be not asingle discrete set of non-overlapping physical possibi-lities but rather a huge smear of classically conceivedpossibilities. Once the physical state of the brain hasevolved into this huge smear of possibilities one mustappeal to the quantum rules, and in particular to theeffects of process 1, in order to connect the physicallydescribed world to the streams of consciousness of theobserver/participants.

This focus on the motions of calcium ions in nerveterminals is not meant to suggest that this particulareffect is the only place where quantum effects enter intothe brain process, or that the quantum process 1 actslocally at these sites. What is needed here is only theexistence of some large quantum of effect. The focusupon these calcium ions stems from the facts that (i) inthis case the various sizes (dimensions) needed toestimate the magnitude of the quantum effects areempirically known, and (ii) that the release of neurotransmitter into synaptic clefts is known to play

a significant role in brain dynamics.The brain matter is warm and wet and is continuallyinteracting intensely with its environment. It might be

thought that the strong quantum decoherence effects

associated with these conditions would wash out allquantum effects, beyond localized chemical processesthat can be conceived to be imbedded in an essentiallyclassic world.

Strong decoherence effects are certainly present, butthey are automatically taken into account in the vonNeumann formulation employed here. These effectsmerely convert the state S of the brain into what iscalled a ‘statistical mixture’ of ‘nearly classically

describable’ states, each of which develops in time (inthe absence of process 1 events), in an almost classicallydescribable way.

The existence of strong decoherence effects makesthe main consequences of quantum theory beingdiscussed here more easily accessible to neuroscientists

by effectively reducing the complex quantum state of the brain to a collection of almost classically describ-able possibilities. Because of the uncertainties intro-duced at the ionic, atomic, molecular and electroniclevels, the brain state will develop not into one singleclassically describable macroscopic state, as it does inclassic physics, but into a continuous distribution of

parallel virtual states of this kind. Process 1 must thenbe invoked to allow definite empirical predictions to beextracted from this continuous smear of paralleloverlapping almost-classic possibilities generated byprocess 2.

(c) Quantum brain dynamicsA principal function of the brain is to receive clues

from the environment, to form an appropriate plan of action and to direct and monitor the activities of thebrain and body specified by the selected plan of action.The exact details of the plan will, for a classic model,obviously depend upon the exact values of many noisyand uncontrolled variables. In cases close to abifurcation point, the dynamic effects of noise mighteven tip the balance between two very differentresponses to the given clues, for example, tip thebalance between the ‘fight’ or ‘flight’ response to someshadowy form. It is important to realize that the exactvalues accounting for what in classic physics models arecalled ‘dynamic effects of noise’ are unknowable in

principle. The contemporary physical model accountsfor these uncertainties in brain dynamics.

The effect of the independent ‘release’ or ‘do notrelease’ options at each of the trigger sites, coupled withthe uncertainty in the timing of the vesicle release ateach of the trillions of nerve terminals, will be to causethe quantum mechanical state of the brain to becomea smeared-out cloud of different macroscopic possibi-lities, some representing different alternative possibleplans of action. As long as the brain dynamic iscontrolled wholly by process 2—which is the quantumgeneralization of the Newtonian laws of motion of classic physics—all of the various alternative possibleplans of action will exist in parallel, with no one plan of action singled out as the one that will actually beexperienced.

Some process beyond the local deterministic process2 is required to pick out one experienced course of physical events from the smeared-out mass of possibi-lities generated by all of the alternative possiblecombinations of vesicle releases at all of the trillionsof nerve terminals. As already emphasized, this otherprocess is process 1. This process brings in a choice thatis not determined by any currently known law of nature, yet has a definite effect upon the brain of thechooser. The process 1 choice picks an operator P andalso a time t at which P acts. The effect of this action attime t is to change the state S (t ) of the brain, or of somelarge part of the brain, to

PS ðt ÞP C ðI KP ÞS ðt ÞðI KP Þ:

The action P cannot act at a point in the brain, becauseaction at a point would dump a huge (in principleinfinite) amount of energy into the brain, which wouldthen explode. The operator P must, therefore, act non-locally, over a potentially large part of the brain.

In examining the question of the nature of the effectin the brain of process 2 we focused on the separatemotions of the individual particles. But the physicalstructures in terms of which the action of process 1 isnaturally expressed are not the separate motions of individual particles. They are, rather, the quasi-stablemacroscopic degrees of freedom. The brain structures

selected by the action of P must enjoy the stability,endurance and causal linkages needed to bring theintended experiential feedbacks into being.

These functional structures are probably more likethe lowest-energy state of the simple harmonic




12/19

oscillator, which is completely stable, or like the statesobtained from such lowest-energy states by spatialdisplacements and shifts in velocity. These shiftedstates tend to endure as oscillating states. In other words,in order to create the needed causal structure theprojection operator P corresponding to an intentionalaction ought to pick out functionally pertinent quasi-stable oscillating states of macroscopic subsystems of thebrain. The state associated with a process 1 preparatoryintervention should be a functionally important brainanalogue of a collection of oscillating modes of adrumhead, in which large assemblies of particles aremoving in a coordinated way. Such an enduringstructure in the brain can serve as a trigger andcoordinator of further coordinated activities.

(d) Templates for actionThe brain process that is actualized by the transition

S (t )/PS (t )P is the neural correlate of the psychologi-cally intended action. It is the brain’s template for theintended action. It is a pattern of neuroelectricalactivity that, if held in place long enough, will tend togenerate a physical action in the brain that will tend toproduce the intended experiential feedback.

(e) Origin of the choices of the process 1 actions

It has been repeatedly emphasized here that thechoices by which process 1 actions actually occur are‘free choices’ in the sense that they are not specified bythe currently known laws of physics. On the other hand,a person’s intentions are surely related in some way totheir historical past. This means that the laws of contemporary orthodox quantum theory, although

restrictive and important, do not provide a completepicture. In spite of this, orthodox quantum theory,while making no claim to ontological completeness, isable to achieve a certain kind of pragmatic completeness.It does so by treating the process 1 ‘free choices’ as theinput variables of experimental protocols, rather thanmechanically determined consequences of brainaction.

In quantum physics the ‘ free choices’ made by humansubjects are regarded as subjectively controllable input

variables. Bohr emphasized that ‘the mathematicalstructure of the quantum mechanical formalism offersthe appropriate latitude’ for these free choices. But the

need for this strategic move goes deeper than the merefact that contemporary quantum theory fails to specifyhow these choices are made. For if in the von Neumannformulation one does seek to determine the cause of the‘free choice’ within the representation of the physicalbrain of the chooser, one finds that one is systematically

blocked from determining the cause of the choice bythe Heisenberg uncertainty principle, which assertsthat the locations and velocities of, say, the calciumions, are simultaneously unknowable to the precisionneeded to determine what the choice will be. Thus, oneis not only faced with merely a practical unknowabilityof the causal origin of the ‘free choices’, but with an

unknowability in principle that stems from the uncer-tainty principle itself, which lies at the base of quantummechanics. There is thus a deep root in quantumtheory for the idea that the origin of the ‘free choices’does not lie in the physical description alone and also

for the consequent policy of treating these ‘free choices’as empirical inputs that are selected by agents and enterinto the causal structure via process 1.

(f ) Effort It is useful to classify process 1 events as either

‘active’ or ‘passive’. Passive process 1 events areattentional events that occur with little or no feelingof conscious effort. Active process 1 events areintentional and involve effort. This distinction is givena functional significance by allowing ‘effort’ to enterinto the selection of process 1 events in a way that willnow be specified.

Consciousness probably contributes very little tobrain dynamics compared with the contribution of thebrain itself. To minimize the input of consciousness,and in order to achieve testability, we propose to allowmental effort to do nothing but control ‘attentiondensity’, which is the rapidity of the process 1 events.This allows effort to have only a very limited kind of influence on brain activities, which are largely con-trolled by physical properties of the brain itself.

The notion that only the attention density iscontrolled by conscious effort arose from an investi-gation into what sort of conscious control over process1 action was sufficient to accommodate the mostblatant empirical facts. Imposing this strong restrictionon the allowed effects of consciousness produces atheory with correspondingly strong predictive power.In this model all significant effects of consciousnessupon brain activity arise exclusively from a well-knownand well-verified strictly quantum effect known as the‘quantum Zeno effect’ (QZE).

(g) The quantum Zeno effect

If one considers only passive events, then it is verydifficult to identify any empirical effect of process 1,apart from the occurrence of awareness. In the firstplace, the empirical averaging over the ‘Yes’ and ‘No’possibilities in strict accordance with the quantum lawstends to wash out all effects that depart from whatwould arise from a classic statistical analysis that

incorporates the uncertainty principle as simply lackof knowledge. Moreover, the passivity of the mentalprocess means that we have no empirically controllablevariable.

However, the study of effortfully controlled inten-tional action brings in two empirically accessiblevariables, the intention and the amount of effort. Italso brings in the important physical QZE. This effect isnamed for the Greek philosopher Zeno of Elea, andwas brought into prominence in 1977 by the physicistsMisra & Sudarshan (1977). It gives a name to the factthat repeated and closely spaced observational acts caneffectively hold the ‘Yes’ feedback in place for anextended time-interval that depends upon the rapidityat which the process 1 actions are happening . According toour model, this rapidity is controlled by the amount of effort being applied. In our notation, the effect is to

keep the ‘Yes’ condition associated with states of theform PSP in place longer than would be the case if noeffort were being made. This ‘holding’ effect canoverride very strong mechanical forces arising fromprocess 2.




13/19

The ‘Yes’ states PSP are assumed to be conditionedby training and learning to contain the template foraction which if held in place for an extended period willtend to produce the intended experiential feedback.Thus, the model allows intentional mental efforts totend to bring intended experiences into being. Systemsthat have the capacity to exploit this feature of naturallaw, as it is represented in quantum theory, wouldapparently enjoy a tremendous survival advantage oversystems that do not or cannot exploit it.

6. SUPPORT FROM PSYCHOLOGY

A person’s experiential life is a stream of consciousexperiences. The person’s experienced ‘self ’ is part of this stream of consciousness: it is not an extra thing thatlies outside what the person is conscious of. In James’swords (1890, p. 401) ‘thought is itself the thinker , andpsychology need not look beyond’. The experiential‘self’ is a slowly changing ‘fringe’ part of the stream of consciousness. This part of the stream of consciousness

provides an overall background cause for the centralfocus of attention.

The physical brain, evolving mechanically in accord-ance with the local deterministic process 2, can do mostof the necessary work of the brain. It can do the job of creating, on the basis of its interpretation of the cluesprovided by the senses, a suitable response, which willbe controlled by a certain pattern of neural or brainactivity that acts as a template for action. However, owingto its quantum character, the brain necessarily gen-erates an amorphous mass of overlapping and conflict-ing templates for action. Process 1 acts to extract fromthis jumbled mass of possibilities some particular

template for action. This template is a feature of the‘Yes’ states PSP that specifies the form of the process 1event. But the quantum rules do not assert that this‘Yes’ part of the prior state S necessarily comes intobeing. They assert, instead, that if this process 1 actionis triggered (for example, by some sort of ‘consent’)then this ‘Yes’ component PSP will come into beingwith probability Tr PSP /Tr S , and that the ‘No’ statewill occur if the ‘Yes’ state does not occur, where thesymbol Tr represents a quantum mechanical sum-mation over all possibilities.

If the rate at which these ‘consents’ occur is assumedto be increasable by conscious mental effort , then the

causal efficacy of ‘will’ can be understood. Consciouseffort can, by activation of the QZE, override strongmechanical forces arising from process 2 and cause thetemplate for action to be held in place longer than itwould be if the rapid sequence of process 1 events werenot occurring. This sustained existence of the templatefor action can increase the probability that the intendedaction will occur.

Does this quantum-physics-based concept of theorigin of the causal efficacy of ‘will’ accord with thefindings of psychology?

Consider some passages from Psychology: the briefer course, written by William James. In the final section of

the chapter on attention, James (1892, p. 227) writes:

I have spoken as if our attention were wholly

determined by neural conditions. I believe that the

array of things we can attend to is so determined. No

object can catch our attention except by the neural

machinery. But the amount of the attention which an

object receives after it has caught our attention is

another question. It often takes effort to keep the mind

upon it. We feel that we can make more or less of the

effort as we choose. If this feeling be not deceptive, if

our effort be a spiritual force, and an indeterminate

one, then of course it contributes coequally with the

cerebral conditions to the result. Though it introduce nonew idea, it will deepen and prolong the stay in

consciousness of innumerable ideas which else would

fade more quickly away.

In the chapter on will, in the section entitled

‘Volitional effort is effort of attention’, James (1892,p. 417) writes:

Thus we find that we reach the heart of our inquiry into

volition when we ask by what process is it that the

thought of any given action comes to prevail stably in

the mind.

And, later:

The essential achievement of the will, in short, when it

is most ‘voluntary,’ is to attend to a difficult object and

hold it fast before the mind..Effort of attention is thus

the essential phenomenon of will.

Still later, James says:

Consent to the idea’s undivided presence, this is effort’s

sole achievement.Everywhere, then, the function of

effort is the same: to keep affirming and adopting the

thought which, if left to itself, would slip away.

This description of the effect of will on the courseof mental–cerebral processes is remarkably in line

with what had been proposed independently from purely

theoretical considerations of the quantum physics of this

process. The connections specified by James areexplained on the basis of the same dynamic principlesthat had been introduced by physicists to explain

atomic phenomena. Thus the whole range of science,from atomic physics to mind–brain dynamics, has the

possibility of being brought together into a singlerationally coherent theory of an evolving cosmos that

is constituted not of matter but of actions by agents. Inthis conceptualization of nature, agents could natu-

rally evolve in accordance with the principles of

natural selection, owing to the fact that their effortshave physical consequences. The outline of a possible

rationally coherent understanding of the connectionbetween mind and matter begins to emerge.

In the quantum theory of mind/consciousness–brain

being described here, there are altogether three pro-cesses. First, there is the purely mechanical process

called process 2. As discussed at length in the book, Mind, matter, and quantum mechanics (Stapp 1993/2003,p. 150), this process, as it applies to the brain, involves

important dynamic units that are represented by

complex patterns of brain activity that are ‘facilitated’(i.e. strengthened) by use and are such that each unit

tends to be activated as a whole by the activation of several of its parts. The activation of various of these

complex patterns by cross referencing—that is, by

activation of several of its parts—coupled to feedbackloops that strengthen or weaken the activities of




14/19

appropriate processing centres, appears to account forthe essential features of the mechanical part of thedynamics in a way that is not significantly different fromwhat a classic model can support, except for theexistence of a host of parallel possibilities that accordingto the classic concepts, cannot exist simultaneously.

The second process, von Neumann’s process 1, isneeded in order to pick out from a chaotic continuumof overlapping parallel possibilities some particulardiscrete possibility and its complement. (The comp-lement can be further divided, but the essential actionis present in the choice of one particular ‘Yes’ statePS (t )P from the morass of possibilities in which it isimbedded.) The third process is nature’s choicebetween ‘Yes’ and ‘No’. Nature’s choice conforms to

a statistical rule, but the agent’s choice is, withincontemporary quantum theory, a ‘free choice’ that canbe and is consistently treated as an input variable of theempirical protocol.

Process 1 has itself two modes. The first is passive,and can produce temporally isolated events. Thesecond is active and involves mental effort.

Active process 1 intervention has, according to thequantum model described here, a distinctive form. Itconsists of a sequence of intentional purposefulactions, the rapidity of which can be increased witheffort. Such an increase in attention density, defined asan increase in the number of observations per unittime, can bring into play the QZE, which tends to holdin place both those aspects of the state of the brainthat are fixed by the sequence of intentional actionsand also the felt intentional focus of these actions.Attention density is not controlled by any physical ruleof orthodox contemporary quantum theor

Teoria Cuantica y Neurociencias

Documents

Transcript of Teoria Cuantica y Neurociencias