Wednesday, July 26, 2006

Parapsychology: The alien hand syndrome, Ardhnarishwar and the epileptic (dis)connection

There is a post by NeuroPhilosopher regarding Parapsychology (psi phenomena) and their plausible explanations. It is an excellent summary of some of the usual suspects and how they can be explained.

I am intrigued by the fact that almost all explanations (except possibly those involving Magical thinking) seem to be one-way or the other related to temporal lobe stimulation/epilepsy and differential processing of information by the two hemispheres.

To quote,

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All psi phenomena include a blurring of the distinction between perception
and imagination; many involve reports of a sensed presence and distortions in
the perception of time.

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Further,

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It is well documented that patients with temporal lobe epilepsy often report having paranormal or religious experiences. In fact, both kinds of experiences can be evoked experimentally by magnetic stimulation of the tempero-parietal region. These regions, which are involved in awareness of the 'self', trigger the experience of a sensed presence when stimulated.

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Interesting to note, that temporal region is implicated in time perception and most psi phenomena, as noted, involve distortions in time-perception.

Further on, in the blog-post, it is speculated that 'Automatic writing' may be attributable to phenomenon like Somatoparaphrenia, which involve attribution of paralyzed left hand (in case of right brain stroke) as belonging to spouse/doctor. Though the facilitated communication case, in which one alleges that the hand is not controlled by oneself, is qualitatively different from the paralyzed hand belonging to spouse/doctor, the two may share the same mechanism with the pathological case being a permanent manifestation vis-a-vis the temporary possession of hand during automatic writing. It is intriguing to note, that in the Hindu culture, spouse is believed to be the owner of the left side of one's body and even one of the gods is Ardhnarishwer : or half-male-half-female. Also, in Hindu rituals, the spouse (wife) normally sits
on left side during auspicious occasions.

If one refers to the basic developmental schema that I believe in and advocate: viz 5 + 3 = 8 stage development; then once the brain has differentiated into 2 halves (the right and left hemispheres ) then to enhance its cognitive maps it may allocate one hemisphere to see the cognitive map in one 'spin' direction; while allowing the other hemisphere to see the map from another 'spin' direction (possibly the 'spin' direction utilized by the spouse/partner.

We already know that left/right asymmetries do exist for many factors like abstract via-vis concrete etc. So if the right brain is associated with spouse (which seems logical as we can only perceive from spouse's viewpoint abstractly and not in the concrete details that are available to our-selves ...and thus the right brain would be the place from which to view the cognitive map in a black-box abstract view, while utilizing left hemisphere for concrete self perceptions), then a stroke in that region may cause the left brain which is used to process inputs from the right-as that from the spouse's viewpoint) to assume that the body regions governed by the right actually belong to the spouse. In the normal, no-stroke, condition, signal processing in right brain may nullify this effect.

Further on, it is speculated, that Ouja boards may be due to the alien hand syndrome (normally evident in people who have a partial disconnection of the anterior corpus callosum, the bundle of one hundred milliofiberses connecting the two hemispheres of the brain). In this case, maybe the mechanism implicated is the seventh stage of brain evolution, wherein group effects come
into prominence. To elaborate, when feedback between the 2 hemispheres is not proper, then in a group situation of an ouja board, it may appear to the left brain (that may be involved in self consciousness more heavily), that the left hand is actually controlled by the group and by not the person individually.

This may explain why ouja boards need a group situation and if this is true then left hand should be more heavily used in such procedure involving 'collective unconscious'.

Finally, it is argued that alien-hand-syndrome is also exhibited in split-brain patients (who have been subject to commissurotomies to protect them from life-threatening and incurable temporal lobe epilepsies.) Again, severing the feedback from the hemispheres to each other, can lead to effects related to the eighth stage of brain developmental tasks viz: transcedence and integrity. Here, the split-brain may not feel integrated and thus refuse ownership of some of the body parts it controls.

Roger Sperry and Gazzaniga experiments on the split-brain patients are very instructive. In one experiment with split brain patients, the left hand handles some object behind a screen ( and the sensory information required to recognize the object is available to the right brain) and they are shown some keywords to the right eye (and thus these words are available to the left brain) and when asked to choose a keyword, the patient would choose a keyword that was related to the object that was being handled by the left hand. For example, if the left hand was handling an injection, then the right eye (and the person as a whole would choose nurse for the list of keywords . (The actual experiment I just remembered was a bit reverse to that...in it an object related to keywords shown was picked up...but this distinction does not affect our discussion) . When the split-brain patients were asked to describe why they chose the particular keyword (or object), they would come up with all sort of valid narratives and confabulations and rationalizations.

These experiments demonstrate that we compose elaborate narratives to explain something (choices we have made) that has been the result of unconscious processing, but have resulted in conscious behavior. Thus, many psi phenomenon, that seem inexplicable today, may be due to us gathering some unconscious inference, but as the information or the method of acquiring that information, is not readily available to consciousness, we indulge in magical thinking. We are able to correlate things, but the science is not adequate enough (in terms of being in the purview of consciousness realm) and thus we cannot decisively draw a scientific causal relation.

Thus, while Neurphilosopher came to the conclusion that more light on psi phenomena will be thrown as we get to know more about consciousness, I believe our understanding of unconscious processes would also be very relevant here.

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1 comment:

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