Date:    Tue, 6 Oct 1998 13:20:41 +0000
From:    Saul-Paul Sirag <sirag@POND.NET>
Subject: [q-mind] Libet data and causation -- Henry Stapp
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From: Henry Stapp <stapp@thsrv.lbl.gov>

Subject: Libet data and causation.
         Reply to Fred Alan Wolf, Libet and subjective timing
           (q-mind: 3 Oct 1998)

    [Wolf]
 I don't think it is easy to grasp why consciousness is not something
that can be explained by classical physics and that even quantum physics
is problematic.  I am now convinced, we need to go beyond ordinary
quantum physics.   I am in agreement with Penrose, Sarfatti, and others
on this.

    [Wolf]
 There are really two different Libet experiments (a) dealing with
intent and (b) dealing with passive awareness.  Neither is explainable
using simple neural network theory or classical physics or even
straightforward quantum physics.

[Stapp]
 Would you please review your (conclusive) proof of your above statement
pertaining to (a) and "staighforward quantum mechanics".

 There are at least three points that need to be dealt with carefully.

 (1) Critics have argued that the data is not conclusive pertaining
Libet's claimed displacement in the timings of the experience of the
intent and the (earlier) start of the neural activities that will
eventuate in the willed motor response.

 (2) Critics have pointed out that our mind plays tricks upon us, as
regards timings, and so that maybe the `experience of willing' actually
occurs sooner than it "seems" to occur: there may be some sort of delay
that serves survival needs by creating a useful illusion.

 (3) Even if we dismiss the arguments of critics mentioned above, and
grant that the timings are indeed as Libet claims, there is an
`apparent' retroactive effect that is built into orthodox quantum
theory, and that, as I argued in my book MM&QM, would nicely accommodate
Libet's claims, accepted at face value.

 Perhaps this "retroactive" effect WITHIN orthodox causal quantum theory
is important enough to warrants a review.

 By orthodox quantum theory I mean what Wigner meant: essentially what I
have been calling the pragmatic vN/W interpretation. [The entire
universe is represented by a quantum state S(t) that evolves in
accordance with the Schroedinger equation between jumps that occur at a
sequence of times

..., t_{n-1}, t_{n} ,t_{n+1},... [t_{n} is t subscript n etc.]

 Each jump is associated with an experiential increment in knowledge,
and with an associated "physical" event (P_e S P_e), where P_e acts on
the degrees of freedom associated with some brain. [Eventually, some
generalization must be made, as explained previously, but at present
this pragmatic approach will do]. Nevertheless, the transformation
S-->(P_e S P_e), acting on the entangled state S of the universe will,
*automatically within the quantum formalism*, act on the state of the
entire universe, and bring it into accord with the increment of
knowledge `e' that was associated preferentially with just one brain.

 That is how the von Neumann rigorous formulation of quantum theory
works. [Even though this formalism was originally placed in a
nonrelativistic context, it can be used in relativistic quantum field
theory, modulo  difficulties at Planck scale seemingly associated with a
breakdown of the idea of space-time at such tiny scales. If these
problems at very tiny  distances, and hence very large energies, are
ignored then one as a beautiful and consistent mathematical formalism
that accounts for all empirical data that is accounted for by either
classical or quantum theory.]

 I assume that the quantum rules hold exactly: if one relaxes this
condition then tremendous flexibility ensues; one can allow one's
imagination to run wild. But the proper way of science is first to see
whether the data can be accommodated within the most orthodox framework,
without allowing violations of the *predictions* of the theory, which is
something that "all" quantum physicists agree about, no matter which
ontological or interpretive framework they may favor.

 To discuss the "retrokinetic" effect that occurs within this orthodox
"forward-directed" causal theory it is useful to consider the
radioactive decay experimnent discussed by Einstein in the Schilpp
volume [ Albert Einstein: Philosopher-Scientist. Tudor, 1951, p. 668].
There is a radiactive isotope surrounded by a detector connected to a
pen that makes a mark on a moving scroll, with a blip indicating the
time of detection of the decay. The Schroedinger equation alone
generates the creation of a superposition of all possible blip
positions: the time of the decay is not defined. In the pragmatic vN/W
theory the collapse occurs when some (first) human observer sees (say on
October 4) the blip on the scroll at a location that is marked, e.g.,
"1:07 PM October 2, 1998".
 All subsequent human observations will be compatible with the decay
having occurred at that moment. [There may have been all sorts of
devices set up to measure various related phenomena.] In the theory, the
experience of the human observer [or eventually proto-observer] that
first observers any of the related phenomena will cause the state S of
the entire universe to collapse to a form compatible with that
experience, and all subsequent experiences will be concordant with that
first one.

 In the Libet case the "willing" experience occurs at some time t. This
collapses the state to one that is compatible with *that* experience
occurring at that time. That experience occurring at that time
corresponds to some brain state in which there was a precursor neural
activity. Suppose that neural activity was monitored by devices that are
read only later [than the "willing" experience] by various scientists.
Then those scientists will see meter readings that indicate that the
precursor neural activity started before the "willing" occurred. Yet the
theory is completely causal in the sense that the independent inputs are
experiential events, which occur in a sequence, with each of these
events causing a collapse that specifies a new state S that evolves into
the future and controls the probabilities for future experiential
events. There is no backward causation at the basic level. However, an
experience `e' at one time can easily and automatically cause a later
experience e~  to depend upon `e' via specifications that have
effectively fixed the state S in such a way as to  "lead to `e' ". This
gives an `apparent' backward-in-time effect, even the though the
causation is either instantaneous or forward.
 [The instantaneous interaction is best  understood in the Heisenberg
picture, in which the operators evolve deterministically throughout all
space-time, once and for all, and the quantum state evolves in "process
time", as I have explained in many places]

 Various attitudes can be adopted for how best to understand this
situation. One can speak of a backward in time causal influences. But
that can become confusing. By far the simplest option, conceptually, and
mathematically, is to recognize that one *does* have some sort of
nonlocal effect in quantum theory, and use this fact to justify the
causal vN/W pragmatic interpretation, where each experiential event `e'
does cause the tranformation S-->(P_e S P_e).

 Everything else then just follows from the basic formulas of quantum
theory without any ambiguities about back-ward causation, and advanced
potentials, and `handshakes'. That whole system of words  leads to
nothing more than what the direct unambiguous use of the vN/W
mathematical formulas give--- unless one wants to depart from the actual
predictions of quantum theory. But I believe that no such departure is
needed to explain the Libet data, accepted at face value, or the
Helmut-Schmidt-type data.

 Given the adequacy of this simple direct causal orthodox theory to
account for these data, and also for the bona fide-ness, in the specific
sense described in earlier postings, of our intuitive understanding of
`mental force' and `free will', there would appear to be little or no
motivation for scientific studies of the brain/mindsystem to frivolously
discard at this point, or mutilate, what the giants of twentieth science
have bequeathed to us.