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perception. However, mental imagery seems to be the efferent activation of some subset of the
brain's visual areas, subserving the same types of functions (what, where, color, spatial attention,
and so on) in imagery and in perception. As already mentioned (I.3.), impairments of specific
regions of the cortex specialized for vision do not only affect the perception, but also the
imagination, memory, and dreaming of colors, for example. If the mind is somewhat autonomous,
how could that be? A similar reply can be made with respect to memory. Declarative memory is
located in the neocortex, as it seems. If the mind can "read" informations from the neocortex and
"write" them into it in some sense, it is mysterious why lesions in deeper structures (hippocampus,
mammilary bodies, thalamic nuclei etc.) cause amnesia (cf. Vaas, 1994).
(3) Exocytosis depends on large proteins e.g. the formation of fusion pores (cf. Walch-Solimena,
Jahn and Sudhof, 1993, Weis and Scheller, 1998). It is unlikely that quantum effects can play a
significant role here i.e. trigger configuration changes on the level of macromolecules. Under the
known presynaptic conditions, Heisenberg's Uncertainty Principle ∆p × ∆x ≥ h works only for
masses in the range of hydrogen atoms and for time scales in the femtosecond regime. It is by no
means clear how such tiny quantum effects could trigger exocytosis i.e. could open the presynaptic
and vesicle membrane. Even worse, if they really could, it is a mystery why these acausal events
do not disrupt the neuronal activities and hence the organization of perception and behavior.
(4) There is a tension between mental causation and quantum physical indeterminism, i.e.,
acausality. Of course, Eccles needs the indeterministic and probabilistic nature of quantum effects
to avoid violation of conservation laws. (For the sake of argument, the indeterministic nature of the
quantum world might be taken for granted here despite some other views still under discussion.)
This loophole in the causal nexus of nature is necessary but not sufficient for interactionist dualism.
According to Eccles, the Self is able to change quantum probabilites (or select specific quantum
states) and trigger neuronal activities in a goal-directed way. So not only must he fill causal gaps in
nature with mindful interventions but he also needs some sort of nonphysical causal power - i.e., a
new ontological type of causality - to explain the occurrence and efficacy of (self-) consciousness.
But this implies a violation of the quantum mechanical probability distributions which is purely
statistical.
(5) Furthermore, there is the problem of physical laws of conservation despite Eccles' claims that
the mind does not violate the first law of thermodynamics. In the interactionistic picture, the mind
must exchange information with the brain, but the current state of physics either postulates a
transformation of matter or energy along with information processing or these events do not carry
information at all. But even if such intended quantum effects do occur and do not violate
conservation of energy because of Heisenberg's uncertainty principle ∆E × ∆t ≥ h (and would not
decrease global entropy!), cortex activities depend as a matter of fact on large amounts of energy
consumption, even during imagery and "pure" ideation, as PET and fMRI scans show. So why
should and how could tiny quantum effects trigger the highest brain functions without any energy at
all?
(6) Even if they could, how does an Ecclesian Self manage to control the myriads of transmitter-
releasing synaptic vesicles without totally disrupting or disorganizing perception, thinking and motor
commands? This is the well-known problem of Jordan's amplification hypothesis (Bunning 1935,
1943). (Inspired by quantum mechanics, Pascal Jordan (1934, 1938) has developed a similar
hypothesis to rescue free will earlier this century.) And Eccles must postulate amplification (and
explicitely does) because otherwise his hypothetical quantum effects would be ineffective.
(7) Next, in calculating the amplification effects very precisely to avoid catastrophic
disorganization and errors in perception and behavior, the Self must know more than even quantum
mechanics allows (because of Heisenberg's uncertainty principle). And it must be a little Laplacean
demon, computing infinitely fast, because the brain is a complex system showing strong nonlinear
(or chaotic) dynamics at many different levels which cannot be predicted in practice (Jirsa and
Vaas, 1995, Vaas, 1995a).
(8) Furthermore, to give a dualistic explanation of Libet's (1993) experimental findings of neural
delays, retrograde stimulus masking, and subjective referral backwards in time, Eccles needs to
postulate that the Self "plays tricks with time" (Popper and Eccles, 1977, p. 364, 475), i.e., changes
the temporal order! This violates causality and the direction of time. Rejecting his dualism and the
(materialist) assumption of a "Cartesian theatre" where all perceptions gather and become
conscious, one can explain these findings much better in terms of a "multiple draft" approach
(Dennett, 1991), assuming that perceptual discriminations are distributed across the brain in both
space and time (cf. I.2.).