7. KNOWLEDGE OR POTENTIA.

The original "Copenhagen" approach took quantum theory to 
be a practical tool that allows scientists to form, on the basis 
of past experiences, reliable expectations about future ones. 
The reality described by that theory was "our knowledge", 
and inquiry into the nature of the reality in which this 
knowledge is imbedded was discouraged. However, human 
beings are an inquisitive lot, and even Heisenberg was not 
immune to the disease of wanting to know more than one's 
philosophy allows.

The success of a theory that allows empirically measured 
numbers to be computed to an accuracy of one part in a 
hundred million says a lot about the reality. It rules out a host 
of possibilities, and places stringent conditions on the rest. 
Thus an understanding of the structure this immensely 
successful theory permits reasonable conjectures to be 
advanced about the nature of the whole of which our 
experiences are but a tiny a part.

Heisenberg in his 1958 book Physics and Philosophy 
allowed himself to speculate on the nature of the reality lying 
behind our streams of conscious thoughts. He ties his idea 
of Nature to the Aristotelian idea of "potentia", which is an 
objective tendency for some particular thing to happen. Each 
such `happening' is a transition from `possible' to `actual'. 

Heisenberg's conjecture is compactly summarized in his 
statement:

"If we want to describe what happens in an atomic event we 
have to realize that the word `happens'  applies to the 
physical not the psychical act of observation, and we may 
say that the transition from the `possible' to the `actual' takes 
place as soon as the interaction between the [atomic] object 
and the measuring device, and thereby with the rest of the 
world, has come into play: it is not connected with the act of 
registration of the result in the mind of the observer. The 
discontinuous change in the probability function, however, 
takes place with the act of registration, because it is the 
discontinuous change in our knowledge at the moment of 
registration that has its image in the discontinuous change in 
the probability function."
[Physics and Philosophy, Harper and Rowe, New York, 
1958, p.54]

At first sight this passage seems self-contradictory: it says 
that the sudden change occurs at the device, not in the 
mind, and then says that it occurs in the mind. But there is 
no contradiction. The sudden change when the interaction 
between object and device comes into play refers to the 
transition from the `possible' to the `actual', which is what 
happens physically, but about which Copenhagen quantum 
theory officially says nothing, whereas the probability 
function is what quantum theory deals with, and it changes 
when our knowledge changes. Thus Heisenberg, by this 
two-level description, one dealing with physical reality, the 
other with psychological reality, reconciles the Copenhagen 
viewpoint with our desire to understand what is really going 
on.

This idea that some real event actually occurs when the 
interaction between object and measuring device comes into 
play accords well with the quantum mathematical 
description. One can believe that the quantum state in the 
mind of the physicist is a mental image of an external (to 
human minds) mathematical reality that corresponds to a 
potentia, or set of objective tendencies, for the physical 
device to respond in each of its alternative possible modes. 
These objective tendencies can be measured by the relative 
frequencies of the various alternative possible outcomes. 
This idea of the connection between probability and reality is 
called "the propensity interpretation of probabilities", and it 
immediately gives an objective picture of a physical reality 
that accounts in a natural way for the success of the 
Copenhagen rules pertaining to our knowledge of that 
reality.

The "potentia" for the occurrence of some particular one of a 
set of mutually exclusive alternative possibilities naturally 
drops to zero when another one of the set of possibilities 
actually happens. So this model, based on the idea that 
physical reality is made out of potentialities, or objective 
tendencies, allows the faster-than-light effects to be 
understood as the instantaneous change in the real objective 
potentialities that constitute the physical world when one of 
the alternative possibilities is actualized. 

Heisenberg thus refers in this single passage to two different 
possible ways of understanding nature, one based on the 
speculative notion of objective physical tendencies, the other 
on the more secure idea of subjective psychological realities. 

8.SYNTHESIS.

John von Neumann is one of the premier minds of the 
twentieth century. A renowned mathematician and logician, 
he was also a principal creator of the concepts of the 
modern computer. In his 1932 book The Mathematical 
Principles of Quantum Mechanics he placed that theory on a 
firm mathematical foundation, and examined also the 
delicate issues associated with the role of the conscious 
observer. The original Copenhagen treatment of the 
observer relied heavily on the pragmatic premise that 
problems that do not intrude significantly into practical 
applications can be ignored. 

If one seeks to go beyond merely a set of rules that work for 
us, and propound a rationally coherent conception of the 
reality in which our human experiences are imbedded, then 
the faster-than-light problem must be dealt with in some way. 
Heisenberg's idea of a world of "potentialities" is the most 
parsimonious possibility: it brings in no needless entities, 
except for the doubling of actual events: there are both 
physical events associated with the transitions from possible 
to actual, and also the psychological events, which occur in 
the mind of the observer. To make a cohesive theory a 
connection is needed between the physically described 
ontology (theory of what exists) and the psychologically 
described epistemology (theory of what we know).

The need for this bridge leads to the technical problem of 
what defines the "devices" where the transitions from 
possible to actual are supposed to occur. Micro-fabrication 
techniques allow extremely tiny device-like structures to be 
built. Their behaviors are probed by bigger devices etc., and 
the nerve cells with receptors in the retina can also be 
regarded as measuring devices, as can higher-level brain 
structures. The quantum rules allow all of these structures to 
be represented in principle as quantum systems. Yet in a 
more precise sense none of them can. For each such 
system is imbedded in a larger whole from which it cannot 
be disentangled within the mathematical quantum 
framework. The only physical system that is strictly 
describable within quantum theory is the entire universe. 

Von Neumann bit the bullet. He showed how the validated 
predictions of quantum theory, which were based on the idea 
of restricting the quantum system to the small system being 
probed by the measuring device, could be preserved and 
understood by expanding the quantum system to include the 
entire universe, including the complete brains of all the 
observers, provided he identified the physical events as 
brain events that actualize the neural correlates of an 
associated psychological event. This identification of the 
subjective experience upon which Copenhagen formulation 
of quantum theory is based as an aspect of the physical 
brain event that actualizes the pattern of brain activity that 
corresponds to that psychological experience synthesizes 
the two interpretations offered by Heisenberg, and it 
establishes a close natural correspondence the two parts of 
nature that Rene Descartes put asunder. It places the 
experiences that are the realities upon which the 
Copenhagen interpretation rests into the physical world of 
potentialities that Heisenberg identified as external reality 
that is the carrier of the real "happenings." This identification 
of, or association of, experiential events with quantum brain 
events establishes a direct mathematically defined causal 
linkage between the experiential and physical aspects of 
Nature. It repairs the terrible damage inflicted on natural and 
moral philosophy by the followers of Descartes. (Descartes 
himself allowed these two aspects of nature to interact within 
brains, in accordance with intuition, common sense, and 
quantum theory, but the mechanical dynamical 
completeness of classical physical theory seemed to forbid 
any kind of interaction between these two so differently 
conceived kinds of reality. However, the freedom given to 
experimental agents by the quantum laws rehabilitates 
Descartes original position.)

This solution is perhaps a quantum version of the "identity 
theory" solution of the mind-brain problem in classical 
physics. However, here it arises from a natural synthesis of 
two incomplete theories that each separately require events 
that the synthesis amalgamates. The important difference, 
however, is that this psychophysical event is not just a 
passive automatic consequence of the micro-causal 
deterministic evolution specified by the Schroedinger 
equation, which is the quantum analog of the classical laws 
of motion. There is an element of freedom that lies beyond 
the compass of the known laws of nature. A second process 
is needed to complete the dynamics. This is the "twenty 
questions" procedure, which involves first a free choice of 
question posed by the actor/observer, and then a statistically 
governed answer delivered by nature. In von Neumann's 
step-by-step passage from the Copenhagen version of 
quantum theory to the final synthesis, the psychologically 
described actor/observer always retains the function of freely 
choosing which question to be put to nature, and this 
freedom persists in the limit. This freedom associated with 
the second process, which von Neumann calls Process I, 
must be retained in the limit because the questions must get 
posed for the dynamics to work, and the discrete questions 
cannot be naturally selected by the continuous dynamics. 
The question thus naturally arises: To what extent can this 
very limited freedom, granted to the human actors, to pose 
questions, be used to influence that person's mental 
process, and hence bodily behavior?


9. THE EFFICACY OF MENTAL EFFORT.

We feel innately that our thoughts themselves actually do 
things: that they influence our succeeding thoughts and 
actions; that our felt mental effort is actually causing our 
muscles to bulge as we strain to budge our trapped vehicle.
Classical physics tells us that this most deeply felt of all our 
convictions, and the basis of all our mental actions, is shear 
poppy-cock; a queer illusions that besets our addled mind. 
Brain does it all, we are told, and our thoughts and feeling 
are but some ineffectual supernumeraries, or nothing 
beyond the functional complex patterns of motion of tiny 
atomic particles.

But if common sense be any guide then our thoughts and 
feelings must be doing something that our classically 
conceived brains alone cannot do as well. For why else 
would nature produce, in addition to the motions of the 
particles, such realities as feelings and ideas. And how could 
these logically unnecessary and disjoint supernumeraries 
evolve if they themselves contribute nothing to our fitness.

Quantum theory provides a natural place for our thoughts, 
and an essential dynamical role for them to play. Our 
psychologically described essence does what our physically 
described brains alone cannot do: it selects the questions 
associated with the crucial collapse process. This latter 
process actualizes certain of the potentialities that inhere in 
the quantum state of the brain, and that are carried forward 
in time by the Schroedinger equation of motion. That 
physically described evolution creates multiple continua of 
potentialities but cannot actualize any one of them. 

The actualization procedure is a two-step operation. First a 
specific question must be selected. This choice must be 
rooted in the psychologically described aspect, because 
making a discrete choice of question, represented by a 
specific projection operator P, lies beyond the capacity of 
amorphous continuum of potentialities represented by the 
state vector V: it cannot discriminate one set of N 
perpendicular vectors from others differing only 
infinitesimally from the first set. Given the selected question, 
nature delivers her answer, which is both psychologically 
experienced and etched in the brain structure by the 
quantum collapse V?PV. This model of the mind-brain 
connection provides a contemporary-science-based 
alternative to the classical-physics-based model.

In this model the dynamical role of consciousness is 
extremely restricted: it can do nothing but influence the 
choices of questions associated with von Neumann's 
process I. That severe restriction is, in fact, what gives the 
theory its predictive and explanatory power.

But how can the mere selection of questions influence 
behavior? In classical physics it could not, since everything 
is predetermined, and while asking a question and getting an 
answer may illuminate the mind of the passive observer, it 
cannot actually influence what happens. But in quantum 
mechanics the situation is quite different. There is an 
important and well-studied effect in quantum theory that 
depends on the timings of the reduction events arising from 
the queries put to nature. It is called the Quantum Zeno 
Effect.

The effect is simple. If the same question is put to nature 
sufficiently rapidly and the initial answer is Yes, then any 
noise-induced diffusion, or force-induced motion, of the 
system away from the subspace where the answer is `Yes' 
will be suppressed: the system will tend to be confined to the 
part of the Hilbert space where the answer is `Yes'. The 
effect is sometimes called the ``watched pot'' effect: 
according to the old adage ``A watched pot never boils''; just 
looking at it keeps it from changing. Also, a state can be 
pulled along in some direction by posing a rapid sequence of 
questions that change sufficiently slowly over time. In short, 
according to the dynamical laws of quantum mechanics, the 
freedom to choose which questions are put to nature, and 
when they are asked, could allow mind to influence the 
behavior of the brain. However, the effect is extremely 
limited: it is merely the tendency to hold in place the focus of 
mental attention. The drift in attention that would normally 
arise from quantum uncertainties, noise, and even ordinary 
forces, is held in check by incessant probing.

A person is aware of almost none of the processing that is 
going on in his brain: unconscious brain action does almost 
everything. So it would be both physically unrealistic and 
theoretically unfeasible to give mind unbridled freedom: the 
questions posed by mind ought to be determined in large 
measure by the brain itself.

But then what freedom is given to mind? 

According to quantum theory, the freedom given to Nature 
herself is merely to provide Yes or No answers to questions 
posed by subsystems. It seems reasonable to restrict in a 
similar way the freedom given to human minds. 

It is easy to construct a simple dynamical model in which the 
brain does most of the work, and the mind, merely by means 
of choices of whether or not pose the question presented by 
the brain, influences the course of mental---hence also 
bodily---action. 

Consider the set of projection operators P that act only on 
the brain of some individual, and that correspond to possible 
mental events of that individual. Quantum theory assigns a 
probability to each such P at each instant of time t. Consider 
at each time t the P that has the greatest probability. It 
represents the ``best possible'' question to ask at that 
moment: it has accumulated the greatest statistical weight. 
Suppose that when the probability associated with this 
possible event reaches a maximum the associated question 
"shall the possible experience associated with P be 
actualized?" is put to nature. If nature returns the answer 
`Yes', then the transition V?PV occurs, along with the 
associated experience. The new dynamical postulate is that 
the "feel" of this event can activate an "effort" that can 
instigate a sequence of posings of this same question that is 
rapid on the time scale of the evolution of PV. The dynamical 
rules of quantum theory then ensure that the rapid-fire 
posings of this question will keep the brain in the subspace 
associated with the answer Yes. 

If a process like this operates then the course of brain and 
body events would be influenced by the effort produced by 
the "feel" of mental events.

The Quantum Zeno Effect will not freeze up the brain 
completely. It merely keeps the state of the brain in the 
subspace where attention is focussed on a particular idea. 

Does this theory of the connection between mind and brain 
explain anything?

Essentially this model 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 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.''
  
This description of the effect of mind on the 
course of mind-brain process is remarkably 
in line with what had been proposed independently 
from purely theoretical consideration of the 
quantum physics of this process. The connections 
specified 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 an evolving cosmos that consists of a 
physical reality that is constituted not of matter 
but of potentia for events to occur. And these 
events include, but are certainly not restricted to, 
collapses to reduced states that bring this physical
reality into accord with the increments of human 
knowledge that pragmatic quantum theory
is based upon.

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 influence activities in our brains. The 
behaviorist approach, which dominated psychological 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, was surely 
motivated in part by the fact that consciousness was 
excluded from any role in brain dynamics by the physics of 
the preceding century 

The failure of the behaviorist programs 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'' 
[32] 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 objective data. Two key concepts are 
the notions ``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 
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 mind-brain being described here 
there are two separate processes. First, there is the 
unconscious mechanical brain process governed by the 
Schroedinger equation. As discussed at length in my earlier 
book, Mind, Matter, and Quantum Mechanics, this brain 
processing involves dynamical units that are represented by 
complex patterns of neural activity (or, more generally, of 
brain activity) that are ``facilitated'' by use, and 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, coupled to feed-back 
loops that strengthen or weaken the activities of appropriate 
processing centers, seems to explain the essential features 
of the mechanical part of the dynamics. 

The function of the brain is to create and direct courses of 
action appropriate to the circumstances in which the 
organism finds itself. Accordingly, the brain ought to create a 
template for a possible plan of action. Detailed examination 
of the quantum uncertainties associated the motion in nerve 
terminals of incoming calcium ions from the ion channels to 
the triggering sites for the release of vesicles of 
neurotransmitter entail [MM&QM, p.152] that a host of 
different possibilities will emerge. This mechanical phase of 
the processing already involves some selectivity, because of 
the enhancing and inhibiting feedback loops. But the 
essential point is that the evolution of the brain according to 
the Schroedinger equation must generate not just one single 
template for action, but a host of alternative possibilities. 
Hence the action of the second process, von Neumann's 
Process I must come into play in order to select what 
actually happens from the continuum of alternative 
possibilities generated by the mechanical aspect of the full 
quantum dynamics. But Process I involves the element of 
freedom that feeds into the Quantum Zeno Effect.

This conception of brain dynamics seems to accommodate 
all of the perceptual aspects of the data described by 
Pashler. But it is the high-level processing, which is more 
closely linked to our active mentally controlled conscious 
thinking, that is of prime interest here. The data pertaining to 
this second process is the focus of part II of Pashler's book.

Mental intervention has, according to the quantum-physics-
based theory described here, several distinctive 
characteristics. It consists of a sequence of discrete events 
each of which consents to an integrated course of action 
presented by brain. The rapidity of these events can be 
increased with effort. Effort-induced speed-up of the rate of 
occurrence of these events can, by means of the quantum 
Zeno effect, keep attention focussed on a task. Between 100 
and 300 msec of consent seem to be needed to fix a plan of 
action. 

Effort can, by increasing the number of events per second, 
increase the mental input into brain activity. Each conscious 
event picks out from the multitude of quasi-classical 
possibilities that comprise the quantum brain the sub-
ensemble that is compatible with the conscious experience. 

The correspondence between the mental event and the 
associated physical event is this: the physical event reduces 
the prior physical ensemble of alternative possibilities to the 
sub-ensemble compatible with the mental event. This 
connection constitutes the core postulate of Copenhagen 
quantum theory: the physical event reduces the prior state of 
the system to the part of it that is compatible with the 
experience of the observer.

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 mind-brain quantum events that von 
Neumann quantum theory is built upon. 

Pashler [p. 279] describes four empirical signatures for this 
kind of bottleneck, and describes the experimental 
confirmation of each of them. Much of part II of Pashler's 
book is a massing of evidence that supports the existence of 
a central process of this general kind.

This bottleneck is not automatic within classical physics. A 
classical model could easily produce simultaneously two 
responses in different modalities, say vocal and manual, to 
two different stimuli arriving via two different modalities, say 
auditory and tactile. The two processes could proceed via 
dynamically independent routes. Pashler [p. 308] notes that 
the bottleneck is undiminished in split-brain patients 
performing two tasks that, at the level of input and output, 
seem to be confined to different hemispheres.

The queuing effect for the mind-controlled motor responses 
does not exclude interference between brain processes that 
are similar to each other, and hence that use common brain 
mechanisms. Pashler [p. 297] notes this distinction, and 
says ``the principles governing queuing seem indifferent to 
neural overlap of any sort studied so far.'' 

The important point here is that there is in principle, in the 
quantum model, an essential dynamical difference between, 
on the one hand, the unconscious processing carried out by 
the Schroedinger evolution, which generates via a local 
process an expanding collection of classically implementable 
possible courses of action, and, on the other hand, the 
process associated with the sequence of conscious events 
that constitutes a stream of consciousness. The former are 
not limited by the queuing effect, because all of the 
possibilities develop in parallel, whereas the latter do form 
elements of a single queue. The experiments cited by 
Pashler all appear to support this clear prediction of the 
quantum approach.

An interesting experiment mentioned by Pashler involves the 
simultaneous tasks of doing an IQ test and giving a foot 
response to a 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. [p. 299] This 
result supports the prediction of quantum theory that the 
bottleneck pertains both to `intelligent' behavior, which 
requires conscious processing, and to selection of motor 
response.

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 into the physical process, via quantum 
selection and reduction, bits of control information that reflect 
mental evaluation.

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 evaluation and a selection or 
focussing on a course of action, and that this resource can 
be divided between tasks.

Additional supporting evidence comes from the studies of 
the effect of the conscious process upon the storage of 
information in short-term memory. According to the physics-
based theory, the conscious process merely actualizes a 
course of action, which then develops automatically, with 
perhaps some occasional monitoring. Thus if one sets in 
place the activity of retaining in memory a certain sequence 
of stimuli, then this activity can persist undiminished while 
the central processor is engaged in another task. This is 
what the data indicate. 

Pashler remarks that ''These conclusions contradict the 
remarkably widespread assumption that short-term memory 
capacity can be equated with, or used as a measure of, 
central resources.''[p.341] In the theory outlined here short-
term memory is stored in patterns of brain activity, whereas 
consciousness is associated with the selection of a sub-
ensemble of quasi-classical states. This distinction seems to 
account for the large amount of detailed data that bears on 
this question of the connection of short-term-memory to 
consciousness. [p.337-341]

Deliberate storage in, or retrieval from, long-term memory 
requires focussed attention, and hence conscious effort. 
These processes should, according to the theory, use part of 
the limited processing capacity, and hence be detrimentally 
affected by a competing task that makes sufficient 
concurrent demands on the central resources. On the other 
hand, ``perceptual'' processing that involves conceptual 
categorization and identification without conscious 
awareness should not interfere with tasks that do consume 
central processing capacity. These expectations are what 
the evidence appears to confirm: ``the entirety of...front-end 
processing are modality specific and operate independent of 
the sort of single-channel central processing that limits 
retrieval and the control of action. This includes not only 
perceptual analysis but also storage in STM (short term 
memory) and whatever may feed back to change the 
allocation of perceptual attention itself.'' [p. 353]

Pashler describes a result dating 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: 
creating physical force by muscle contraction requires an 
effort that opposes the physical tendencies generated by the 
Schroedinger equation. 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.
 
Pashler speculates on the possibility of a neurophysiological 
explanation of the facts he describes, but notes that the 
parallel versus serial distinction between the two 
mechanisms leads, in the classical neurophysiological 
approach, to the questions of what makes these two 
mechanisms so different, and what the connection between 
them is. [p.354-6, 386-7]

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.'' 
Thus the fact that this bottleneck, and its basic properties, 
follow automatically from the same laws that explain the 
complex empirical evidence in the fields of classical and 
quantum physics means that the theory has significant 
explanatory power.

Of course, the fact that this theory seems to work so well 
does not mean that it is the only theory that can work. But in 
the past science has been well served by the endeavor of 
trying to understand various complex high-level processes in 
ways that all fit together coherently with basic physical 
theory. The brain is a physio-chemical structure that rests in 
principle on quantum processes, and the quantum principles 
lead in a completely natural way to a specified kind of 
dynamical linkage between the aspects of the mind-brain 
that are described in psychological and physical terms. All 
classically described features are accounted for in the 
quantum description, which however provides also a natural 
dynamical place for mind whereas classical physics does 
not.

There is, of course, no empirical evidence that favors the 
classical model over the quantum model described above. 
Quantum theory automatically accounts for all the successes 
of classical physical theory. So all simple physiological and 
anatomical features of the physical brain can, according to 
quantum theory, be treated classically. The quantum 
description becomes necessary only when treating subtle 
dynamical effects. The effect of mental effort to hold ideas in 
place longer than classical computations would predict 
would seem to be the most crucial dynamical difference 
between the classical and quantum models.

Brain science has suffered through a century of trying to 
force itself into a mold it did not fit, namely a now 
superceded physics that left a key player out. Ought it not 
now try just as hard to fit itself into the framework of the 
more correct science that explicitly brings in, rather than 
denying the existence of, the efficacious thoughts and 
feelings that are prima facie features of the structure it 
studies? And should not psycho-physics benefit from having 
a theoretical model that accords with all physics 
requirements, yet includes both the psychological and 
biological elements it studies, and specifies their ontological 
and dynamical relationship to each other. Should not 
psychology and psychiatry benefit from having a model of 
the human being as a psychologically described agent that 
interacts with the rest of nature through his body in specified 
ways, rather being forced to conceive the human being as a 
bundle of cells that behave in wholly mechanical ways that 
contradict the basic laws of nature. If basic physical theory 
was forced to adopt the realistic view of the human person 
as a psychologically described agent why should psychology 
not follow suit? Finally, ought not evolutionary biology benefit 
from allowing human person's to have efficacious minds that 
can contribute to their fitness, and thus naturally evolve in 
step with their physical carriers?