Friday, December 28, 2012

Von Neumann quantum theory is a formulation in which the entirephysical universe, including the bodies and brains of the conscioushuman participant/observers, is represented in the basic quantumstate, which is called the state of the universe. The state of asubsystem, such as a brain, is formed by averaging (tracing) thisbasic state over all variables other than those that describe the stateof that subsystem. The dynamics involves three processes

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4. The von Neumann/Stapp Approach
Von Neumann quantum theory is a formulation in which the entire
physical universe, including the bodies and brains of the conscious
human participant/observers, is represented in the basic quantum
state, which is called the state of the universe. The state of a
subsystem, such as a brain, is formed by averaging (tracing) this
basic state over all variables other than those that describe the state
of that subsystem. The dynamics involves three processes.
Process 1 is the choice on the part of the experimenter about how he
will act. This choice is sometimes called “The Heisenberg Choice,”
because Heisenberg emphasized strongly its crucial role in quantum
dynamics. At the pragmatic level it is a “free choice,” because it is
controlled, at least in practice, by the conscious intentions of the
experimenter/participant, and neither the Copenhagen nor von
Neumann formulations provide any description of the causal origins
of this choice, apart from the mental intentions of the human agent.
Each intentional action involves an effort that is intended to result in a
conceived experiential feedback, which can be an immediate
confirmation of the success of the action, or a delayed monitoring the
experiential consequences of the action.
Process 2 is the quantum analog of the equations of motion of
classical physics. As in classical physics, these equations of motion
are local (i.e., all interactions are between immediate neighbors) and
deterministic. They are obtained from the classical equations by a
certain quantization procedure, and are reduced to the classical
equations by taking the classical approximation of setting to zero the
value of Planck’s constant everywhere it appears. Evolution via the
quantum Process 2 normally has the effect of expanding the
microscopic uncertainties demanded by the Heisenberg uncertainty
principle into the macroscopic domain: the centers of large objects
tend to become diffused over large regions. The disparity between
this Process-2-generated theoretical indefiniteness and the
consciously experienced definiteness of the positions of visible
objects is resolved in quantum theory by invoking Processes 1 and 3.
Process 3 is sometimes call the “Dirac Choice.” Dirac called it a
“choice on the part of Nature.” It can be regarded as Nature’s answer
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to a question effectively posed by the Process 1 choice made by the
experimenter. This posed question might be: Will the Geiger counter
be observed to be in the intended position? Or, Will the Geiger
counter be observed to “fire” in accordance with the experiential
conditions that define a ‘Yes’ response? The application of quantum
theory demands the formulation/posing/choosing of a definite yes-or-
no question – or a set of such questions – in connection with each
potential experience for which a prediction is to be made.
Although Process 1 brings the conscious choices made by the
observer/participant into the dynamics in an essential way, there is a
tendency for this dependence upon the agent’s choice to be wiped
out by the subsequent averaging over the two possible answers,
‘Yes’ and ‘No,’ to any question posed by Process 1. However, Stapp
has pointed out that if willful effort can adequately control the rate at
which a sequence of similar Process 1 events occur then willful effort
can become highly causally efficacious: such a sequence of events, if
sufficiently rapid, can hold certain properties of the brain in a
subspace corresponding to a certain conscious intention. This
consciously controllable arresting of the state of attention can thus
hold in place, in the brain, a “template for intentional action,” and the
prolongation of the activation of this pattern of brain activity can tend
to produce the intended physical action of the body or brain, in
accordance with William James’s “ideo-motor” theory of action
(James, 1890: 522)
This “holding effect” of a rapid sequence of similar Process 1 events
is an automatic consequence of the von Neumann equations of
motion, and it has been extensively studied, both empirically and
theoretically, by quantum physicists under the title “The Quantum
Zeno Effect.”
This quantum account of the origin of the causal efficacy of conscious
will (effort) corresponds closely to the ideas of William James, as is
made evident by the following quotations:
``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
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mind.'' (James, 1890:564)
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.''
The important conclusion is that the apparent capacity of conscious
effort to influence physical actions, which seems so puzzling and
illusory within the framework of classical physical theory, flows
naturally from the equations of quantum theory.
The question arises: What causes this causally efficacious feeling of
effort or will?
The classical-physics-based response is to affirm the belief – or faith
– that the cause is completely describable in micro-local terms: in
terms of essentially mechanical contact interactions between tiny
physical elements. But this faith is not based on science! Science
tells us that the old micro-local classical ideas cannot be correct.
Consequently, there is no rational reason to insist, on the basis of
science, that the cause of the feeling of effort must be describable
microlocally. Idea-like qualities are certainly parts of reality, and there
is no evidence from science that they cannot be irreplaceable
components of the causal chains that connect our experiences to
each other. Contemporary basic physical theory explicitly introduces
into the dynamical equations the physical effects of our conscious
choices about how to act, and it is counterproductive, at least at the
level of practical science, to eliminate these pertinent, controllable,
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and knowable variables in favor of idealized theoretical concepts that
are known to be false, and involve parameters that are unknowable
not only in practice but also in principle.
This tripartite quantum dynamics involving Choice, Causation, and
Chance [Processes 1, 2, & 3, respectively] and the implementation of
Will (Volition) via the conscious control of the rapidity of Process 1
events, provides the foundation of a quantum approach to neuro-
psychology. But how well does this quantum approach work in actual
practice?
The Pashler Data
A great deal of experimental work over the past three decades in the
field of The Psychology of Attention is summarized in Harold
Pashler’s book of that title [Pashler, 1998].
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. [pp. 33, 263, 293, 317, 404.] He
argues that the former processes are carried out in parallel, but that
the latter processes, which seem to require effortful choosing,
operate in series, and have a capacity that can be enlarged by willful
effort, but is limited.
Pashler’s conclusion is based on the analysis of a huge array of
recent experiments. But the central finding is succinctly illustrated in 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,
if we take the sequence of Process I events associated with an agent
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to have a limited “capacity” in terms of events per second, then this
effect is an automatic consequence of quantum theory: creating a
physical force by muscle contraction requires a conscious effort that
prolongs the existence of the neural template for action that opposes
the Process-2-generated tendency of the brain to evolve toward a
more relaxed state. This prolongation is produced by the Quantum
Zeno Effect, and its effect 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.
This example is just one simple case. But it illustrates the general
principle: identification of Pashler’s limited central serial “capacity”
with the rate of occurrence of Process 1 events, assumed to be
increasable by willful effort, up to a limit, appears to explain the
general features of all of the many diverse empirical results cited by
Pashler in support of his thesis. ( Stapp, 2001)
This success of von Neumann’s psychophysical theory in accounting
for Pashler’s data does not mean that classical physics could not be
supplemented in an ad hoc way that would enable it to match that
performance. However, the von Neumann theory allows the data to
be explained directly in terms of the already existing explicitly
described tripartite process that constitutes the core of contemporary
basic physical theory, whereas an explanation based on classical
physics is not only predicated on the untenable idea that microlocal
causation can be extended to the realm of the motions of ions within
nerve terminals, but also rests on a theory that, although false, is
dynamically and logically complete without entailing the existence of
consciousness. In contrast, von Neumann’s equations, namely those
that specify the effects of Process 1 and 3, specify definite dynamical
connections between consciousness and brain activity, and they do
so in a theoretical framework that automatically entails all of the valid
predictions of classical physics. So what is the rationale, in neuro-
psychology, for rejecting the fundamental equations of contemporary
physics, which encompass consciousness, and all of the
phenomenally valid classical features, in an empirically satisfactory,
logically coherent, and practically useful way, in favor of classical
concepts that are known to be fundamentally false and that leave
consciousness out?
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The Libet Data
Probably the best way to understand the essence of the quantum
approach to consciousness is to see, in detail, how it applies to the
famous Libet experiments about willful action. (Libet, 2003)
The “problem” with the Libet data is that when an action is ‘willed’–
such as ‘willing’ a finger to rise– a readiness potential (RP) appears
before the experience of ‘willing’ appears. Libet explains this by
saying that the conscious choice to perform this action does not occur
until the state of readiness is in place: the conscious choice is simply
a choice either to “Veto” or “Consent To” a specified action, whose
physical ‘template for action’ is already in place, imbedded in the
structure of a particular pattern of neural activity. [This is slight
elaboration upon Libet’s explanation.]
In the exposition that follows I shall introduce some symbols and
equations. Non-physicists should regard each of these as just a
pictorial or symbolic representation of the corresponding idea that I
describe in words, together with the promise that this picture, in the
minds of physicists, encodes a definite mathematical procedure.
Quantum theory is based on Heisenberg’s discovery that the
empirical facts of physics (many of which are logically incompatible
with the basic precepts of classical physics) can be described by a
new theory, quantum theory, which can be constructed by replacing
the “numbers” in classical physics by “actions” (operators). [The
ordering of the numbers in a product does not matter, but the order in
which actions/operations are performed does matter.]
In vN/S theory the dynamics of a conscious brain depends critically
upon an essential correspondence between certain actions/operators
in the mathematical structure and associated human experiences.
Each such action is represented by a “projection operator” P, which
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satisfies PP=P. [The double action PP of a projection operator P has
the same effect as a single action P.] If the experience is labeled by
‘e’ then the associated projection operator is represented by P(e). In
von Neumann’s formulation of quantum theory this operator P(e) acts
upon the state of the brain of the observer/participant/agent and
specifies the neural correlate of the experience ‘e.’ The mappings
P(e) specify a mind-to-matter correspondence that plays a key role in
the dynamics of the brain of a conscious agent.
Any adequate theory of the connection between the stream of
consciousness and the brain processes of the conscious agent must
involve connections between conscious events and associated
patterns of brain/neural activity. These are the so-called “neural
correlates of consciousness,” the NCC’s. But technical differences
between classical theory and quantum theory render the dynamical
roles of the NCC’s very different in these two theories. In classical
theory the conscious events are either (perhaps “emergent”) causally
inert by-products of brain activity that have no influence on physical
processes. or they are certain properties of a person’s brain activity
that can be described in terms of the concepts of classical physics,
and that also appear in streams of consciousness as psychologically
describable experiences. In both cases, the person’s conscious
experiences play no essential causal role in the determination of his
actions, in the sense that the causal chain can be described in purely
physical terms. On the other hand, a person’s conscious choices
enter irreplaceably into the quantum dynamics as free input variables,
replacing the in-principle-unknowable classically conceived
parameters.
Here, in more detail, is how the theory works!
The (quantum) state S of a system is an action/operator, called “the
statistical operator” [or “the density matrix.”] It specifies the statistical
weight [probability] of every projection operator P associated with that
system. The formula for the statistical weight of P – the probability of
getting the answer ‘Yes’ to the question associated with P – in the
state S is:
<P> = Trace PSP/Trace S.
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[If A is an action/operator then Trace A is a number that is generated
by performing a certain kind of quantum averaging process on A.
Normally an operator “acts on” the operator that stands to its right.
But the rightmost operator in a chain can also act back around on the
left-most operator of that chain, like a snake biting its own tail. This
produces the “Trace” of that chain of operators, which might be a
single operator. The connection of the mathematical formulas to
measurable numbers is always given by this Trace operation.]
Quantum dynamics is built upon these operators P(e) and S, and on
two kinds of choices. The first kind of choice is made by the
experimenter/observer/participant. It is called “Process 1” by von
Neumann.
The other kind of choice was called by Dirac “a choice on the part of
nature.” I have called it “The Dirac Choice.” I also call it “Process 3” to
distinguish it from von Neumann’s Process 1 and Process 2. [Process
2 is the quantum analog of Newton’s classical equation’s of motion,
and is obtained by replacing classical numbers by corresponding
quantum operators.]
In classical physics there is just one dynamical process, namely the
classical approximation to the quantum Process 2. But orthodox
quantum theory has two additional processes, one involving a choice
made by a conscious participant/agent/observer about how he will
act, and one made by Nature about how she will respond to the
agent’s choice.
Contemporary orthodox quantum theory does not specify what the
agents’s choice will be. In atomic physics the agent’s choice is
treated as a free variable that is fixed by the aims of the
experimenter/participant. These aims are considered to lie outside
the realm of atomic physics. They are to be covered by neuro-
psychology, and are presumably determined by some combination of
the neurological-physical and psychological-experiential processes
that enter into quantum neurodynamics.
Figuring out exactly what this combination is, from a detailed analysis
of the psycho-neurological data, is the task of neuroscience,
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psychology, and physics, working together. Only the general overall
quantum dynamical framework was provided by von Neumann.
To get a preliminary general orientation, I have proposed a simple
model for the agent’s choice.
The state S(t) of the participant’s body-brain is defined by taking the
“partial trace (over all other degrees of freedom in the universe)” of
the state of the universe at time t (say, in the rest frame of the cosmic
background radiation, just to be specific.)
Then the projection operator P(t) is defined to be that operator in the
set {P(e)} that maximizes
Trace P(e)S(t)P(e)/Trace S(t).
This special P(t) is the P(e) that has at time t the greatest statistical
weight.
As a first guess, I propose that a Process 1 event associated with
P(T) occurs automatically at any time T=t such that <P(t)> = Trace
P(t)S(t)P(t)/Trace S(t) reaches a local (in time) maximum. This
Process 1 puts to Nature the question: Does the quantum jump of
S(T) to the state P(T)S(T)P(T) occur?
Notice that the timing and form of this event is determined jointly by
the physical side, from S(T), and by the psychological side from P(T).
But it is determined, nevertheless, by a mathematical law: it is not
coming from “out of the blue.” The Process 1 event changes S(T) to
S’(T) = P(T)S(T)P(T) + P’(T)S(T)P’(T), where P’ = (1-P).
Then Nature’s choice, Process 3, occurs. It is a “quantum jump.” The
State S’(T) is reduced to P(T)S(T)P(T) with probability Trace
P(T)S(T)P(t)/Trace S(T) or to P’(T)S(T)P’(T) with probability Trace
P’(T)S(T)P’(T)/Trace S(T). If the chosen state is P(T)S(T)P(T), then
the associated experience ‘e’ occurs: otherwise no experience occurs
in conjunction with this Process 3 event.
This “experience” occurs essentially automatically, if Nature’s
Process 3 answer is ‘Yes’. The occurrence of the experience is a
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consequence of these partly deterministic and partly statistically
deterministic equations. Consciousness enters only indirectly, by
virtue of the limitation on the set {P(e)} of all P(e)’s, which enters into
the definition of P(t).
Conscious Will comes in if the state actualized by the ‘Yes’ choice on
the part of Nature not only eliminates all components of the brain
state that fail to have the template for an action specified by P(T), but
also puts to the agent the question “shall I exert the effort needed to
ask again of nature, almost immediately, the question specified by
P(T)”. If the rapidity of these Process 1 events is sufficiently great
then this sequence of Process 1 events will activate the Quantum
Zeno Effect, which will tend to hold the state S(t) in the subspace
defined by this P(e), and this can, according to James’s ideo-motor
theory, produce the physical raising of the finger, which should lead
to the feedback experience ‘e’ of raising the finger.
This completes the more detailed description of the basic elements of
vN/S theory, which will now be applied to the Libet experiment.
The original commitment by the subject to, say, “raise my finger
within the next minute” will condition his brain to bring forth a
succession of potential RP’s, distributed over the next minute. When
the probability for any one of the potential RP’s in this sequence
peaks (reaches a local maximum) the associated Process 1 question
“shall I initiate the raising of my finger” is asked. Because the
commitment is spread over a minute the probability that Nature’s
answer will be ‘Yes’ will be very small for each individual RP in the
sequence. Hence most of the possible RP’s in the sequence will not
be actualized: they will be tossed out by the “No” answer on the part
of Nature. But for some one of these Process 1 events Nature will say
“Yes,” and the associated initiating experience ‘e’ will occur. If, in the
light of the feelings thus actualized, the agent “chooses to exert the
effort needed to raise the finger”, then a sufficiently rapid sequence of
Process 1 events will be actualized, and this will cause the finger to
rise.
The conscious choice to exert the needed effort that causes the
finger to rise occurs, therefore, after the beginning of the build-up of
the associated readiness potential, just as Libet says. This readiness
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potential is actualized by Nature’s first ‘Yes’ answer. None of the
“potential readiness potentials” associated with the ‘No’ answers to
the earlier Process 1 events will have been actualized. So the
physical situation actualized by the ‘Yes’ answer at some time T will
actualize a physical situation that includes a readiness potential that
has already begun its build up before time T, and peaked at time T.
But the mental decision to consent, not veto, comes after T, and only
if this consent is given will the Quantum Zeno Effect kick in and hold
persistently in place the “template of action” needed to consciously
raise the finger.
It might seem that this occurrence of the build up of the readiness
potential before the conscious choice that triggers the raising of the
finger might violate causality requirements. But the computations of
orthodox quantum theory show that this kind of precursor activity
cannot be controlled in such a way as to, say, send a specified
message backward in time. It is controlled in this case by Nature’s
choice to say ‘Yes’ at time T, not before. Given this ‘Yes” choice on
the part of Nature the (human) agent is given the choice to consent or
veto the rapid sequence that will cause the finger actually rise. This
human choice to consent or veto, on the basis of his feelings, is
treated in quantum theory as a free variable. But one must take into
account the fact that if the consent is given then Nature must choose,
with specified statistical weights, between the ‘Yes’ and ‘No’ answers
to each of the Process 1 questions in the ensuing rapid sequence.
The result is that the granting of the consent can directly and strongly
influence whether or not the finger will rise, but will have no effect, on
the average, on whether or not the precursor readiness potential
appears: the fact that that this RP appears was fixed already by the
‘Yes’ answer given at time T. Consequently, the occurrence of the RP
is not controlled by the subsequent “free choice of whether or not to
exert the needed effort, and there is no conflict with the stringent
causal requirements of the theory of relativity, which forbids sending
controlled messages except via physical transfers of momentum
energy. There can be no such transfer backward in time (or outside
the forward light cone) and hence no violation of the requirements of
the theory of relativity, even though the readiness potential appears
before the conscious choice that actually causes the finger to rise.
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The projection operators P(e) are necessarily nonlocal operators:
they grasp in a unified way an informational structure that can extend
over a large part of the body-brain of the participant. This brings into
the dynamics holistic features that are in principle beyond the reach
of systems that operate according to the local principles of classical
physics. These holistic features are in line with our perception and
conception of ourselves as creatures that can consciously grasp
complex informational structures as wholes, and can choose to act
efficaciously on the basis of those graspings.
Applications in Neuropsychology and Neuropsychiatry
This theory has been applied in both Neuropsychology and
Neuropsychiatry. In the former case (Oschner, 2002; Schwartz, 2003)
human subjects are first instructed how to alter their mental reactions
to emotionally-charged visual stimuli by adopting certain mental
strategies. Then their reactions to such stimuli are studied using fMRI
under differing choices of mental set. The brain scans reveal
profoundly different patterns of response to the stimuli according to
the strategy chosen by the subject. The key empirical input variables
here are the willful choices by the human subject about how he or
she will (mentally) act, and vN/S theory provides a physics-based
framework for analyzing the data in terms of these input parameters,
without being limited by the idea that basic science requires all
psychogenic causes to be explained purely by classically conceived
physiological causes. Indeed, quantum theory says that micro-local
expIanations of brain dynamics in terms of the concepts of classical
physics are impossible in principle, and suggests that willful choices
about how to act be treated as the pertinent causally efficacious
psychogenic input parameters, in line with the treatments of the Libet
and Pashler data.
In the psychiatric cases (Schwartz, 2002) the crucial communication
between therapist and patients was enhanced by instructing the
patients that quantum theory allows bona fide psychogenic influences
of freely chosen actions, and interpreting differences in brain scans of
patients as evidence of the therapeutic value of properly directed
willful conscious control of attention. Psychogenically based therapy
is given a foundation in basic physics. (Stapp, 1999)
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The key elements of the theory are the NCC’s, which are specified by
the projection operators P(e). But how is this mapping between the
two conceptually disparate regimes established. The answer is by
trial and error empirical testing of the correspondence between
quality of conscious effort and quality of experiential feedback. Every
healthy alert infant is incessantly engaged in mapping out the
correspondences between efforts and feedbacks, and he/she builds
up over the course of time a repertoire of correspondences between
the feel of the effort and the feel of the feedback. This is possible
because different effortful choices have, according to the quantum
equations, different physical consequences, which produce different
experiential consequences. This whole process of learning would
appear to depend crucially upon the actual causal efficacy of chosen
willful efforts.
The focus here has been on the theoretical foundations of pragmatic
scientific practice. However, vN/S theory lends itself to ontological
interpretation. The essential change from classical theory is that the
classical state of the universe represents a purported material realty,
whereas the von Neumann quantum state of the universe represents
a purported informational reality. This latter reality has certain matter-
like features: it can be represented in terms of micro-local entities
(local quantum fields) that usually evolve by direct interactions with
their neighbors. But the von Neumann quantum state represents the
collective knowledge of all agents, and it changes whenever the
knowledge of any agent changes. The state changes in three ways:
by the mechanical Process 2; by the injection via Process 1 choices
made by agents; and by the injection via Process 3 of choices made
by Nature. Taken at face value the quantum state of the von
Neumann universe acts like the giant playing board upon which a
game of “choices” is being played between agents and Nature. Quite
apart from the question of “truth,” this “game” conception of quantum
theory provides a good understanding of the practical workings of the
theory.
It should be mentioned that everything said in this section on the vNS
theory is completely compatible with there being very strong
interactions between the brain and its environment: the state S(t) of
the brain is what is know as the statistical operator (reduced density
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matrix) corresponding to the brain. It is formed by averaging (tracing)
over all non-brain degrees of freedom, and incorporates all of the
decoherence effects arising from interactions with the environment.
Von Neumann’s theory provides a general physics-based psycho-
physical framework. We now turn to efforts to tie it to the detailed
structure of the brain.
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Schwartz, J., Stapp, H. & Beauregard, M (2003). The volitional
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Stapp, H. (2001). Quiantum theory and he role of mind in nature.
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