**Quantum Interactive Dualism: An Alternative to Materialism**

Henry P. Stapp

**Abstract**

*René Descartes proposed an interactive dualism that posits an
interaction between the mind of a human being and some of the matter
located in his or her brain. Isaac Newton subsequently formulated a
physical theory based exclusively on the material/physical part of
Descartes' ontology. Newton's theory enforced the principle of the
causal closure of the physical, and the classical physics that grew out
of it enforces this same principle. This classical theory purports to
give, in principle, a complete deterministic account of the physically
described properties of nature, expressed exclusively in terms of these
physically described properties themselves. Orthodox contemporary
physical theory violates this principle in two separate ways. First, it
injects random elements into the dynamics. Second, it allows, and also
requires, abrupt probing actions that disrupt the mechanistically
described evolution of the physically described systems. These probing
actions are called Process 1 interventions by von Neumann. They are
psycho-physical events. Neither the content nor the timing of these
events is determined either by any known law, or by the afore-mentioned
random elements. Orthodox quantum mechanics considers these events to be
instigated by choices made by conscious agents. In von Neumann's
formulation of quantum theory each such intervention acts upon the state
of the brain of some conscious agent. Thus orthodox von Neumann
contemporary physics posits an interactive dualism similar to that of
Descartes. But in this quantum version the effects of the conscious
choices upon our brains are controlled, in part, by the known basic
rules of quantum physics. This theoretically specified mind-brain
connection allows many basic psychological and neuropsychological
findings associated with the apparent physical effectiveness of our
conscious volitional efforts to be explained in a causal and practically
useful way. The intent of this paper is to give an updated account of
the author's developing theory that is clearer than before, focused on
the positive, and suitable for non-specialist readers.*

**The Role of the Observer in Contemporary Physical Theory**

The conception of nature initiated in the seventeenth century by Isaac
Newton developed by the end of the nineteenth century into what is now
called classical physics. According to the precepts of classical
physics, the world is made of classically conceived particles and
classically conceived fields. Classically conceived particles are like
miniature planets, careening through space under the influence of fields
of force generated by these particles. The structure of the theory
entails that once an initial states of all of the particles and fields
in the universe is given, the physical state of the universe at all
later times is fixed by laws that act exclusively at the microscopic
level: the changes occurring at each location in space are determined
wholly in terms of *nearby* properties of these particles and fields.
The causal closure of the physical is thereby ensured.

Difficulties with these classical ideas began to appear around 1900.
Technology had advanced by then to the stage where it was possible to
measure *macroscopic* (visible) properties of large physical systems
whose behaviors depended sensitively upon the behaviors of their
microscopic atomic constituents. The observed results could not be
reconciled with the classical conception of those atomic parts. Late in
the year 1900 Max Planck discovered a new constant of nature that did
not fit the old picture, and it soon became clear that the mounting
perplexities were connected to this constant.

Many of the best mathematical minds of the generation wrestled with this
problem, but it was not until 1925 that Werner Heisenberg discovered the
amazing and unprecedented solution: the numbers that in classical
physics describe the physical properties of a system must be treated as
mathematical actions (operators) instead of numbers. An essential
difference between numbers and actions is that the order in which two
*numbers* are multiplied does not matter\-\--2 times 3 is the same as 3
times 2\-\--but the order in which two *actions* are performed can
matter. According to the rules discovered by Heisenberg, the difference
generated by changing the order in which these actions are applied
involves Planck's constant. In particular, if one takes the equations of
quantum mechanics and replaces Planck's constant everywhere by zero then
one recovers the corresponding classical theory. Classical physics
thereby becomes an "approximation" to quantum physics, namely the
approximation obtained by replacing the true value discovered by Planck
by zero.

Because Planck's constant is an extremely tiny number on the scale of
human activities, the classical approximation is normally a very good
approximation in the realm of phenomena that do not depend upon the
details of what is happening at the atomic level. However, brains are
controlled by ionic processes occurring in nerves, so it is not clear, a
priori, that the classical approximation will always suffice. Indeed, a
detailed examination based on an analysis of the critical brain process
of exocytosis\-\--the dumping of neurotransmitter molecules into the
synaptic cleft that separate communicating neurons\-\--shows that, at
the level of basic principles, quantum mechanics must be used in the
treatment of the dynamical processes occurring in human brains.
(Schwartz, Stapp, and Beauregard, 2005) The classical approximation can,
*for special reasons*, be adequate for many purposes, but the
applicability of the classical approximation to brain dynamics is
neither automatic nor universally guaranteed. According to contemporary
basic physics, quantum mechanics must be used as a matter of basic
principle, with the classical approximation usable in those special
cases where it can be justified.

The most radical departure from classical physics instituted by the
founders of quantum mechanics was the introduction of *human*
*consciousness* into the dynamical and computational machinery. This
change constitutes a revolutionary break with the classical approach,
because the success of that earlier approach was deemed due in large
measure precisely to the fact that it kept consciousness out. However,
the need for a rationally coherent and practically useful theory forced
the creators of quantum mechanics to bring into the theory not merely a
passive observer, superposed ad hoc onto classical mechanics, together
with the knowledge that flows passively into his or her consciousness,
but, surprisingly, an active consciousness that works in the opposite
direction, and injects conscious intentions efficaciously into the
physically described world.

It is, of course, obvious that we human beings do *in practice* inject
our conscious intentions into nature whenever we act in an intentional
way. But in classical physics it was assumed that any such human action
was merely a complex consequence of the purely physical machinery.
However, the quantum generalization of the classical mechanical laws
proposed by Heisenberg and his colleagues do not generate *by
themselves* a dynamically complete deterministic physical theory. They
have a causal gap. Something else is needed to complete the dynamics.

The added element introduced by the founders of quantum mechanics was
called Process 1 by John von Neumann. This process brings consciousness
intentions actively into the dynamics. Such an intention, once actively
chosen, has physical effects that are fixed by the known quantum laws.
*But which one of the set of physically possible intentions will be
chosen, and when that intention will be implemented,* is not determined
by the known laws of quantum mechanics. These are *free choices* in the
specific sense that they are not determined by any currently known laws,
and in practical applications are treated as free input variables of the
theory.

This intrusion of observers into quantum dynamics is not an ad hoc
emendation. It is logically tied to the essential core of quantum
mechanics, namely Heisenberg's replacement of numbers by actions.

A physical theory must correlate certain mathematical aspects of the
theory to empirical data. It must connect certain mathematical features
of the theory to corresponding perceptual realities in the streams of
consciousness of human beings. It is perhaps not unexpected that a
theory whose basic elements are *mathematical actions* should relate
certain mathematical actions to *experiences* associated with *physical
actions.* In quantum theory\-\--in its original and still-used-
for-all-practical-applications form\-\--this is just what happens. The
pertinent physical actions are physical probing actions, where a
*physical probing action* is an action that yields *one* experienced
outcomes or feedback from a set of pre-specified (by Process 1)
experientially distinct possible outcomes.

The paradigmatic example of Heisenberg's replacement of numbers by
actions is this: the number *x* that represent how far a classically
conceived object has moved along a straight line from some base point
*x=0* is replaced by a corresponding mathematical action (or operator)
*x*. This *mathematical action x* is the mathematics counterpart of *the
physical probing action whose outcome would be the number x that
represents the location of the object, insofar as that location is well
defined*. Similarly, the *mathematical action* *p* is the mathematics
analog of the physical probing action that would yield as outcome the
number *p* that specifies the momentum of the object, insofar as this
momentum is well defined. \[The momentum is *p= mv*, where *m* is the
mass of the object, and *v* is its velocity.\]

Not every mathematical action has a physical analog, but every possible
physical probing action is supposed to have a mathematical analog.

Heisenberg's rule asserts that the mathematical actions *x* and *p*
satisfy xp -- px = iħ, where ħ is Planck's constant divided by 2 pi, and
i is a number that when multiplied by itself gives minus one.

Now it might seem that the fact that *xp* differs from *px* by some tiny
number should have no great effect on the basic conceptual structure of
the theory. But that is not the case: this small change upsets the whole
apple cart. The reason is this: the numbers that occur in classical
physics represent the *internal properties* of some physical
system\-\--eventually the entire physical universe\-\--whereas the
action that replaces such a number represents *a probing action
performed upon that physical system by an observing system external to
it.* That is, a number that in classical physics represents an *internal
property of a physical system, with no implicit or explicit reference to
anything external to that physical system*, is replace in quantum
mechanics by an element that represents an *action performed upon that
system by a system that is observing or probing it.*

*This means that the seemingly minor, or merely mathematical, change of
replacing numbers by actions induces an enormous conceptual change. It
shifts the subject matter of the theory from self-contained physical
systems to the interplay between physical systems and observing systems
that actively probe them. A monistic materialist ontology is shifted to
a dualistic one involving observing and observed systems, and these
systems are now causally connected by the mathematically specified
Process 1, which injects the effects of a conscious intent into the
quantum mechanically described properties of the observed system. This
conceptual change is profound.*

Psychophysical Action in Copenhagen Quantum Theory

The formulation of quantum theory proposed by its founders is called the
Copenhagen interpretation. It is epistemological and pragmatic. It is
designed to allow physicists to apply the mathematical rules of quantum
theory to the practical problem of making predictions about observable
outcomes of experiments that they can in principle perform. The theory
is built around the idea that conscious agents design and perform
experiments of their own choosing, observe outcomes, and communicate to
colleagues what they have done and what they have learned. The language
to be used in these communications is described by Bohr:

> \...it is imperative to realize that in every account of physical
> experience one must describe both experimental conditions and
> observations by the same means of communication as the one used in
> classical physics. (Bohr, 1958, p.88).
>
> The decisive point is to recognize that the description of the
> experimental arrangement and the recording of observations must be
> given in plain language suitably refined by the usual physical
> terminology. This is a simple logical demand since by the word
> "experiment" we can only mean a procedure regarding which we are able
> to communicate to others what we have done and what we have learnt
> (Bohr, 1963, p 3)

This description is *psychological*, in the sense that it is a
description of the intentions and perceptions appearing in someone's
stream of consciousness.

The experimenters are, within the framework provided by quantum theory,
free to choose which experiments they will perform. Bohr says:

> \"The freedom of experimentation, presupposed in classical physics, is
> of course retained and corresponds to the free choice of experimental
> arrangement for which the mathematical structure of the quantum
> mechanical formalism offers the appropriate latitude.\" (Bohr, 1958,
> p.73)
>
> "To my mind there is no other alternative than to admit in this field
> of experience, we are dealing with individual phenomena and that our
> possibilities of handling the measuring instruments allow us only to
> make a choice between the different complementary types of phenomena
> that we want to study. (Bohr, 1958, p. 51)

This free choice made by experimenters, and its representation in the
mathematics, is called Process 1 by von Neumann. It is "free" in the
sense that these choices are not determined by anything in contemporary
physical theory: they are fixed neither by any law nor by any of the
random variables that enter into the theory. In actual practice these
choices are made by a human agent, on the basis of his predilections, or
his felt or imagined needs.

Process 1 is represented in the mathematical structure as a division of
the mathematically described quantum state of the system being probed
into a countable set of components, each of which is assigned a
probability in such a way that these probabilities add up to one
(unity). Each of these components is supposed to correspond to a
definite experienced outcome of a probing action, distinguishable from
all the other possible outcomes. After the intervention of this Process
1 decomposition of the state of the probed system into a set of discrete
components, nature chooses one of the possible outcomes of this probing
action. This "choice on the part of nature" is asserted to conform to a
statistical rule. This choice of outcome *obliterates* from the prior
collection of possibilities all components but the chosen one, which is
itself a new smeared out cloud of possibilities, or potentialities.

This "reduction of the wave packet" or "collapse of the wave function"
is asserted to be accompanied by the occurrence in the agent's stream of
consciousness of the experience associated with the chosen component.
The agent thereby acquires *knowledge*: the agent learns something about
the observed system from the experienced feedback from his or her
probing action.

The Process 1 choice of which probing action to take can be represented
in the stream of consciousness of the agent as an intentional choice to
act in such a way as to either receive a specified feedback 'Yes', or
not receive that specified feedback. Multiple choice questions can be
reduced to a sequence of such 'Yes-or-No' questions.

The Mind-Brain Connection in von Neumann's Orthodox Formulation.

The Copenhagen formulation of quantum theory separates the
psycho-physical world into two parts. One is described in terms of the
quantum mathematics, the other in terms of our everyday experiences
refined by the concepts of classical physics.

The founders elected to include in the second part not only the minds
and bodies of the probing agents, but also their physical measuring
devices. That proposal has two awkward features. The first is that the
unified physical world is artificially broken into two parts that are
described differently. The second is that if one has a set of measuring
devices, each one measuring the output of its predecessor, then it
becomes ambiguous just where to draw the line that divides the two
differently described parts of nature.

Von Neumann showed that one can place the entire physical world,
including the bodies and brains of the agents, in the physically
described world. Then the entire physical world is described in the
mathematical language of quantum mechanics. In this von Neumann
formulation the physically described action associated with the
consciously intended probing action by the agent is a mathematically
described action *on the brain of that agent*. The psychophysical causal
connections thereby become *mind-brain* causal connections. This makes
the theory similar to a Cartesian Interactive dualism, *with, however,
causal connections between the two realms now specified, in part, by the
basic laws of physics.*

This feature overcomes the main objection to Cartesian dualism, which
was the lack of any understanding of how a person's mind could have any
effect upon that person's brain.

This von Neumann form of quantum mechanics, in which the entire physical
world is described quantum mechanically, was dubbed the "orthodox
interpretation" by von Neumann's colleague Eugene Wigner. Quantum theory
is built in practice around the Process 1 effect of a person's
psychologically described intentional actions upon physically described
properties, and in the von Neumann formulation these physically
described properties are properties of that person's brain.

The Process 1 actions can be likened to the posing of the 'Yes-or-No'
questions in the game of twenty questions: the agent freely chooses the
questions in accordance with his or her own reasons or feelings, subject
to no known laws, and nature returns answers, subject to specified
statistical requirements.

The Copenhagen interpretation of quantum theory, created by the
founders, was designed to be practical\-\--it was designed to allow
physicists to use the theory to make predictions about their future
experiences of the basis of what they have learned from their prior
probings. Thus human beings played a special role; pigs don't do
physics.

Von Neumann's theory is a development of the *pragmatic* Copenhagen
form. But if one considers the von Neumann theory to be an *ontological
description* of what is really going on, then one must of course relax
the anthropocentric bias, and allow agents of many ilks. Yet the theory
entails that it would be virtually impossible to determine, empirically,
whether a large system that is strongly interacting with its environment
is acting as an agent or not. This means that the theory, regarded as an
ontological theory, has huge uncertainties.

However our interest here is the nature of human agents. Hence the near
impossibility determining the possible existence of other kinds of
agents, will mean that our lack of information about the existence of
those other possible kinds of agents will have little or no impact on
our understanding of ourselves.

\]

The Physical Effectiveness of Conscious Will

An important question now arises: How does the psycho-neurological
connection via Process 1, *which can merely pose questions*, not answer
them, allow a person's conscious choices to exercise effective control
over his or her physical actions?

A Process 1 action appears in the mathematics as a posing of a question.
But it can appear in the consciousness of the agent also as an intention
to achieve some intended feedback. The relevant question is one with
just two possible answers 'Yes' and 'No', where 'Yes' is the desired
feedback and 'No' is the failure of the 'Yes' feedback to occur. But
whether 'Yes' or 'No' appears is not determined by the agent, who
chooses only the question. The answer is picked by "Nature", in
accordance with a specified statistical law. So the effectiveness of
conscious intent would appear to be diluted by the entry of quantum
randomness in the choice (on the part of nature) of the outcome of the
posed question. Indeed, the quantum laws generate, in general, a strong
tendency for the statistical fluctuations in the feedbacks to wipe out,
after appropriate averaging, any net effect of the choice of questions
upon physical properties: the quantum effect of the intent tends to be
washed out by the quantum elements of randomness.

However, a well-known and much-studied feature of quantum theory
provides a natural way out.

[The Quantum Zeno Effect.]{.underline}

An important feature of the dynamical rules of quantum theory is this:
Suppose a Process 1 action that leads to a 'Yes' outcome is followed by
a rapid sequence of very similar Process 1 actions. That is, suppose a
sequence of very similar intentional acts is performed, and that the
actions in this sequence occur in very rapid succession on the time
scale of the evolution of the original 'Yes' state. Then the dynamical
rules of quantum theory entail that the sequence of outcomes will, with
high probability, all be 'Yes': the original 'Yes' state will, with high
probability, be held approximately in place by the rapid succession of
intentional acts, even in the face of very strong physical forces that
would, in the absence of this rapid sequence of intentional acts,
quickly cause the state to evolve into a very different state.

The timings of the Process 1 actions are, within the orthodox
formulations, controlled by the "free choices" on the part of the agent.
So it is consistent and plausible to add to the von Neumann rules the
provision that the rapidity of the succession of essentially identical
Process 1 actions can be increased by mental effort. Then we obtain, as
a strict mathematical consequence of the basic dynamical laws of quantum
mechanics described by von Neumann, a potentially powerful effect of
mental effort on the physical world!

This "holding-in-place" effect is called the quantum Zeno effect. That
appellation was picked by the physicists E.C.G. Sudarshan and R. Misra,
to emphasize a similarity of this effect to a paradox discussed by the
fifth century B.C. Greek philosopher, Zeno the Eleatic.

The *quantum* "holding" effect is a rigorous consequence of the basic
orthodox laws of quantum mechanics, supplemented by the assumption that
mental effort can instigate a rapid repetition of a Process 1 action. In
the present context the intentional act is associated with a macroscopic
pattern of brain/body activity identified as a "Template for Action".
This particular pattern of neural/brain activity is actualized by the
'Yes' response to the Process 1 intentional probing action. The
succession of similar probing actions must occur rapidly on the scale of
the natural time-scale of the template for action in order for the
quantum Zeno effect to come into play and hold this template of action
in place.

The "Quantum Zeno Effect" can, in principle, hold an intention and the
associated template for action in place in the face of strong mechanical
forces that would tend to change the latter. This means that agents
whose mental efforts can increase the rapidity of Process 1 actions
would enjoy a survival advantage over competitors that lack this
feature. Agents who possess this capacity could sustain beneficial
templates for action in place longer than competitors who lack it. Thus
the dynamical rules of quantum mechanics can endow conscious effort with
the causal efficacy needed to permit its evolution and deployment via
natural selection. Given this potentially strong causal effect of mental
effort on brain activity, both the survival dynamics in the evolution of
species and the trial and error learning in the life of the individual
would tend to establish a positive correlation between the conscious
intention associated with a Process 1 action and the functional effect
of this action on the brains of the agents.

Process 1 actions operate within a domain of "Heisenberg uncertainties"
generated by Heisenberg's replacement of numbers by actions. This domain
shrinks to zero in the classical approximation, nullifying all causal
effects of consciousness. Thus, from the perspective of orthodox
contemporary physical theory, any attempt to understand within a
classical idealization of nature the apparent causal effects of our
intentional volitional actions upon the physically described world would
be an irrational endeavor, because it would be based, essentially, on an
approximation that eliminates the effect that one is trying to explain.

[Mind and Brain]{.underline}

A person's experiential life is a stream of conscious experiences. The
person's experienced 'self' is part of this stream of consciousness: it
is not an extra thing that stands outside or apart from the stream. In
James's words "thought is itself the thinker, and psychology need not
look beyond." The "experienced self" is a slowly changing "fringe" part
of the stream of consciousness. It provides a background for the central
focus of attention.

Von Neumann distinguishes the Process 1 interventions from the
"mechanical" Process 2 that governs the evolution of physical systems in
the absence of Process 1 interventions. Process 2 is what arises
directly out the procedure of "quantizing" the classical theory. It
specifies the evolution of physical systems in the absence of any
interventions by observing systems.

The physical brain, evolving mechanically in accordance with the local
deterministic Process 2, necessarily generates, in a continuously
evolving way, not a single well defined template for action, but rather
an amorphous mass of overlapping and conflicting templates for action. A
Process 1 action extracts from this jumbled mass of possibilities a
particular pair of alternative possibilities, one labeled 'Yes' the
other labeled 'No'. If a 'Yes' response occurs and includes a positive
evaluative element that instigates a quick re-posing of the query then
the quantum Zeno effect can convert this positive evaluation into
positive action. Such a use by nature of the quantum Zeno effect would
promote the survival of any species that can exploit it. Thus the
physical efficacy of conscious effort entailed by this quantum model
would provide a naturalistic explanation of how and why our brains
developed in a way that can exploit the quantum Zeno effect.

[William James's Theory of Volition]{.underline}

Does this quantum conception of the dynamical connection between mind
and brain explain anything?

This theory was already in place when a colleague, Dr. Jeffrey Schwartz,
brought to my attention some passages from \`\`Psychology: The Briefer
Course\'\', written by William James. In the final section of the
chapter on Attention James (1892) 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 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 no new idea, it will deepen and prolong the stay
> in consciousness of innumerable ideas which else would fade more
> quickly away. The delay thus gained might not be more than a second in
> duration\-\--but that second may be critical; for in the rising and
> falling considerations in the mind, where two associated systems of
> them are nearly in equilibrium it is often a matter of but a second
> more or less of attention at the outset, whether one system shall gain
> force to occupy the field and develop itself and exclude the other, or
> be excluded itself by the other. When developed it may make us act,
> and that act may seal our doom. When we come to the chapter on the
> Will we shall see that the whole drama of the voluntary life hinges on
> the attention, slightly more or slightly less, which rival motor ideas
> may receive. \...

In the chapter on Will, in the section entitled "Volitional effort is
effort of attention" James 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.

James apparently recognized the incompatibility of these pronouncements
with the physics of his day. At the end of "Psychology: The Briefer
Course" he said, presciently, of the scientists who would one day
illuminate the mind-body problem:

> the best way in which we can facilitate their advent is to understand
> how great is the darkness in which we grope, and never forget that the
> natural-science assumptions with which we started are provisional and
> revisable things.

It is a testimony to the power of the grip of old ideas on the minds of
scientists and philosophers alike that what was apparently evident to
William James already in 1892, namely that a revision of the precepts of
nineteenth century physics would be needed to accommodate the structural
features of consciousness, still fails to be recognized by many of the
affected professionals even today, more than three-quarters of a century
after the downfall of classical physics, foreseen by James, has come,
much-heralded, to pass.

James's description of the effect of volition on the course of
mind-brain process is remarkably in line with what had been proposed,
independently, from purely theoretical considerations of the quantum
physics of this process. (Stapp. 1999) The connections described by
James are explained on the basis of the same dynamical principles that
had been introduced by physicists to explain atomic phenomena. Thus the
whole range of science, from atomic physics to mind-brain dynamics, is
brought together in a single rationally coherent theory of a world that
is constituted not of classically conceived matter, bound by the
principle of the causal closure of the physical, but rather of mind and
matter connected in the way specified by orthodox contemporary physical
theory.

No comparable success has been achieved within the framework of
classical physics, in spite of intense efforts spanning more than three
centuries. The reasons for this failure are easy to see: classical
physics systematically exorcizes all traces of mind from its precepts,
and thereby banishes any logical foothold for recovering causally
effective mind. Moreover, according quantum physics all causal effects
of consciousness act within the latitude provided by the uncertainty
principle, and this latitude shrinks to zero in the classical
approximation, thereby eradicating the causal effects of conscious
intent.

Support from Psychology Data

Much experimental work on attention and effort has occurred since the
time of William James. That work has been hampered by the apparent
nonexistence of any physical theory that rationally explains how our
conscious experiences could actually influence activities in our brains.
The apparent absence of any viable theory of how mind could influence
brain undoubtedly lent support to the behaviorist approach, which
dominated psychology during the first half of the twentieth century, and
which essentially abolished in this field the use not only of
introspective data but also of the very concept of consciousness.

The admitted failure of the behaviorist program led to the
rehabilitation of "attention\'\' during the early fifties, and many
hundreds of experiments have been performed during the past fifty years
for the purpose of investigating empirically those aspects of human
behavior that we ordinarily link to our consciousness.

Harold Pashler\'s 1998 book The Psychology of Attention describes a
great deal of this empirical work, and also the intertwined theoretical
efforts to understand the nature of an information-processing system
that could account for the intricate details of the empirical data. Two
key concepts are the notions of "Attention" and of a processing
"Capacity". The former is associated with an internally directed
selection between different possible allocations of the available
processing "Capacity". A third concept is "Effort", which is empirically
linked to incentives, and to reports by subjects of "trying harder".

Pashler organizes his discussion by separating perceptual processing
from post-perceptual processing. The former covers processing that,
first of all, identifies such basic physical properties of stimuli as
location, color, loudness, and pitch, and, secondly, identifies stimuli
in terms of categories of meaning. The post-perceptual process covers
the tasks of producing motor actions and cognitive action beyond mere
categorical identification. Pashler emphasizes \[p. 33\] that "the
empirical findings of attention studies specifically argue for a
distinction between perceptual limitations and more central limitations
involved in thought and the planning of action." The existence of these
two different processes, with different characteristics, is a principal
theme of Pashler\'s book \[p. 33, 263, 293, 317, 404\]

In the quantum theory of the mind-brain there are two separate
processes. First, there is the unconscious mechanical brain process
called Process 2. A huge industry has developed that tries to map out
these essentially classically describable processes. But, according to
orthodox contemporary physics, another process, von Neumann\'s Process
1, is also entering into the causal story. Its effects become most
manifest in connection with an impulsive feeling described as "effort".
The effect of this "effort of attention" is to inject into brain
activity, and thence into overt behavior, some effects of intentional
input and control that, according to orthodox quantum precepts cannot be
explained in terms of physical causation alone, because the process acts
to bring definiteness out of a realm of physical unknowability and
indefiniteness created by the uncertainty principle.

Two kinds of Process 1 actions are possible. One possible kind would be
determined by brain activity alone. This would be the kind of the action
associated with James's assertion that "No object can catch our
attention except by the neural machinery." A second possible kind of
Process 1 action would presumably involve an evaluation\-\--based on the
felt or experiential quality of an event\-\--that would tend to make the
Process 1 event immediately repeat itself, or quickly come into being
again, with a rapidity that is increasable, up to a certain limit, by a
quality of the event called "effort". Such a Process 1 action could,
within the quantum framework, induce a rapid sequence of similar actions
that would activate a quantum Zeno effect, which would tend to produce
the intended action. .

The "perceptual" aspect of brain process discussed by Pashler can be
associated with Process 2, and with the essentially passive Process 1,
whereas the higher-level processing that Pashler identifies can be
associated with the active mode of Process 1.

Examination of Pashler\'s book shows that this quantum-physics-based
theory accommodates naturally all of the complex structural features of
the empirical data that he describes. He emphasizes \[p. 33\] a specific
finding: strong empirical evidence for what he calls a central
processing bottleneck associated with the attentive selection of a motor
action. This kind of bottleneck is what the quantum-physics-based theory
predicts: the bottleneck is precisely the single linear sequence of
Process 1 actions that the quantum theory of the mind-brain connection
is built upon.

The sort of effect that Pashler finds is illustrated by a result he
describes that dates from the nineteenth century: mental exertion
reduces the amount of physical force that a person can apply. He notes
that "This puzzling phenomena remains unexplained." \[p. 387\]. However,
it is an automatic consequence of the physics-based theory described
here: creating physical force by muscle contraction requires an effort
that opposes the physical tendencies generated by Process 2. This
opposing tendency is produced by the quantum Zeno effect, and is roughly
proportional to the number of bits per second of central processing
capacity that is devoted to the task. So if part of this processing
capacity is directed to another task, then the applied force will
diminish.

An interesting experiment mentioned by Pashler involves the simultaneous
tasks of doing an IQ test and giving a foot response to rapidly
presented sequences of tones of either 2000 or 250 Hz. The subject\'s
mental age, as measured by the IQ test, was reduced from adult to 8
years. Effort can be divided, but the aggregate total level of effortful
Process 1 actions reaches a definite limit at maximal level of effort.

Another interesting experiment showed that, when performing at maximum
speed, with fixed accuracy, subjects produced responses at the same rate
whether performing one task or two simultaneously: the limited capacity
to produce responses can be divided between two simultaneously performed
tasks. \[p. 301\]

Pashler also notes \[p. 348\] that \`\`Recent results strengthen the
case for central interference even further, concluding that memory
retrieval is subject to the same discrete processing bottleneck that
prevents simultaneous response selection in two speeded choice
tasks.\'\'

In the section on \`\`Mental Effort\'\' Pashler reports that
\`\`incentives to perform especially well lead subjects to improve both
speed and accuracy\'\', and that the motivation had \`\`greater effects
on the more cognitively complex activity\'\'. This is what would be
expected if incentives lead to effort that produces increased rapidity
of the events, each of which injects mental intention into the physical
process.

Studies of sleep-deprived subjects suggest that in these cases
\`\`effort works to counteract low arousal\'\'. If arousal is
essentially the rate of occurrence of conscious events then this result
is what the quantum model would predict.

Pashler notes that \`\`Performing two tasks at the same time, for
example, almost invariably\... produces poorer performance in a task and
increases ratings in effortfulness.\'\' And \`\`Increasing the rate at
which events occur in experimenter-paced tasks often increases effort
ratings without affecting performance\'\'. \`\`Increasing incentives
often raises workload ratings and performance at the same time.\'\' All
of these empirical connections are in line with the general principle
that effort increases the rate of conscious events, each of which inputs
a mental intention, and that this resource can be divided between tasks.

A more extended discussion of the Pashler data from the quantum point of
view can be found in Stapp (2001) and in Schwartz, Stapp, and Beauregard
(2005)

After analyzing various possible mechanisms that could cause the central
bottleneck, Pashler \[p.307-8\] says \`\`the question of why this should
be the case is quite puzzling.\'\'

Materialist accounts of these data may be achievable. But the quantum
account conforms to specific laws of physics that tie mental events to
their causal consequences in the brain in a way that appears to conform
to relevant empirical data. A classical account has no such basic
theoretical connections upon which to build a theory. Hence the mind
parts are introduced on the basis of empirical findings alone. This
makes the classical approach logically flabby compared to its quantum
counterpart.

Application to neuropsychology.

The quantum mechanical theory works better in neuropsychology than
classical approaches that enforce the causal closure of the physical. To
illustrate this point let us apply the quantum approach to an experiment
of Ochsner et al. (2002).

Reduced to its essence this experiment consists first of a training
phase in which the subject is taught how to distinguish, and respond
differently to, two alternative possible instructions, given while
viewing emotionally disturbing visual images. One instruction, "attend",
means "passively be aware of, but not try to alter, any feelings
elicited by the stimulus", whereas "reappraise" means "actively
reinterpret the content so that it no longer elicits a negative
response". The subjects then perform these mental actions during brain
imaging. The visual stimuli when passively attended to activate limbic
(emotional) brain areas and when actively reappraised activate
prefrontal cerebral regions.

From the classical materialist point of view this experiment is
essentially a conditioning protocol, where, however, the "conditioning"
is achieved via linguistic communications pertaining to cognitive
concepts. But how do the *cognitive* *realities* of "knowing",
"understanding", and "feeling" arise out of motions of the miniature
planet-like objects of classical physics, which have no trace of any
experiential quality? And how do the vibrations that carry the
instructions get converted into feelings of understanding? And how do
these feelings of understanding get converted to conscious effort, the
presence or absence of which determine whether the limbic or frontal
regions of the brain will be activated?

The materialist claim is that *someday* these connections will be
understood. Karl Popper called this prophecy "promissory materialism".
But can these connections reasonably be expected to be understood in
terms of a physical theory that is known to be false, and, moreover, to
be false because of an approximation that eliminates the object of
study, namely the efficacious causal connection between psychologically
and physically described aspects of the mind-brain system?

There are important similarities and also important differences between
the classical and quantum explanations of the experiments of Ochsner et
al. (2002). In both approaches the atomic constituents of the brain can
be conceived to be collected into nerves and other biological
structures, and into fluxes of ions and electrons, which can all be
described reasonably well in essentially classical terms. But in the
classical approach the physical changes must in principle be
deterministically describe in terms physical variables alone, with no
acknowledgement of the existence of the conscious efforts upon which
they seem to depend, the whereas in the quantum approach the
psychologically and physically described aspects are already dynamically
connected by the basic laws of orthodox contemporary physics in a way
that seems to account nicely for the empirical facts.

.

The quantum laws are organized around psychophysical events that monitor
and guide the physical process in the brain. When no mental effort is
applied, the temporal development of the body/brain will be roughly in
accord with the principles of classical statistical mechanics. But,
according to the quantum laws, important departures from the classical
statistical predictions can be produced by a conscious effort that
increases the rapidity of the monitoring events. Such an increase can
cause to be held in place for an extended period a pattern of neural
activity that constitutes a template for action. The holding-in-place of
this template will tend to cause the action specified by that template
to occur.

In the quantum treatment of the Ochsner experiments the effort of the
subject to "reappraise" *causes* the "reappraise" template to be held in
place, and the holding in place of this template *causes* the
suppression of the limbic response. These causal effects are, via the
quantum Zeno effect, direct mathematical consequences of the quantum
rules. Thus the "subjective" and "objective" aspects of the data are
rationally tied together by quantum rules that directly specify the
causal effects of the subject's choices upon the subject's brain,
without any need to specify the physical antecedents of these choices.

The form of the quantum laws naturally accommodates a dynamical
breakpoint between the *cause* of a willful action, which is not
specified by the theory in its present form, and the *effects* of such
an action, which *are* specified by the theory. Consequently, our
conscious choices can consistently be treated as *empirically specified
consciously controlled input variables*, in accordance with the
experimental protocols, just as they are in the realm of atomic physics,
with the *effects* of these free choices specified by the laws of
physics. That is, the *physical effects* of our consciously chosen
inputs can be described in terms of physics-based rules for these
effects themselves, without needing to say what caused these choices to
be what they are: in the quantum treatment the causal connection via the
laws of physics *is not from the cause of the conscious choice to the
effects of that choice*, but rather directly from the conscious choice
itself to its physical effects.

This quantum causal explanation falls apart if one descends to the
classical approximation. That approximation entirely eliminates the
*direct* effects of our conscious choices upon the physically described
properties of nature. But what is the rational motivation for insisting
on the use of this approximation?

The applicability of the classical approximation to mind-brain
phenomenon certainly does not follow from physics considerations.
Calculations based on the known properties of nerve terminals indicate
that quantum theory must in principle be used. Nor does it follow from
the fact that classical physics works reasonably well in neuroanatomy or
neurophysiology: Quantum theory explains why the classical approximation
works well in those domains. Nor does it follow rationally from the
massive analyses and conflicting arguments put forth by philosophers of
mind. In view of the turmoil that has engulfed philosophy during the
three centuries since Newton cut the bond between mind and matter, the
re-bonding achieved by physicists during the first half of the twentieth
century must be seen as a momentous development: a lifting of the veil.
Ignoring this huge and enormously pertinent development in basic
science, and proclaiming the validity of materialism on the basis of
inapplicable-in-this-context nineteenth century science is an irrational
act.

The only objections I know to applying the basic orthodox principles of
physics to brain dynamics are, first, the forcefully expressed opinions
of some non-physicists that the classical approximation provides an
entirely adequate foundation for understanding brain dynamics, in spite
of the physics calculations that indicate the opposite; and, second, the
opinions of some physicists that the hugely successful orthodox quantum
theory, which is intrinsically dualistic, should, for philosophical
reasons, be replaced by some theory that re-converts human consciousness
into a causally inert witness to the mindless dance of atoms. Neither of
these opinions has any rational scientific basis.

**References.**

Bohr, N. 1958: Atomic Physics and Human Knowledge. New York: Wiley.

Bohr, N. 1963: Essays 1958/1962 on Atomic Physics and Human Knowledge.
New York: Wiley.

James, W. 1892: Psychology: the briefer course. In William James:
Writings 1879-1899. New York: Library of America (1992).

Misra, B. and Sudarshan, E.C.G. 1977: The Zeno's paradox in quantum
theory. Journal of Mathematical Physics 18: 756-763.

Ochsner, K.N. & Silvia A. Bunge, James J. Gross, and John D.Gabrieli
2002: Rethinking feelings: an fMRI study of the cognitive regulation of
emotion. J. Of Cognitive Neuroscience, 14:8, 1215-1229.

Pashler, H. 1998: The Psychology of Attention. Cambridge, MA: MIT Press.

Stapp, H.P. 1999: Attention, Intention, and Will in Quantum Physics,
Journal of Consciousness Studies, 6 (8-9), 143-164.

Schwartz, J., Stapp, H. & Beauregard, M. 2005: Quantum physics in
neuroscience and psychology: a neurophysical model of mind/brain
interaction. Phil. Trans. Royal Society: B 360(1458), 1309-27.

\[http://www-physics.lbl.gov/\~stapp/stappfiles.html\]

Von Neumann, J. 1955/1932: Mathematical Foundations of Quantum
Mechanics. Princeton: Princeton University Press. (Translated by Robert
T. Beyer from the 1932 German original, Mathematiche Grundlagen der
Quantummechanik. Berlin: J. Springer)