On Wednesday, February 26, 2014 11:17:31 AM UTC-5, David Nyman wrote: > > On 26 February 2014 12:58, Craig Weinberg <[email protected]<javascript:> > > wrote: > >> >> "The alien hand syndrome, as originally defined, was used to describe >>> cases involving anterior corpus callosal lesions producing involuntary >>> movement and a concomitant inability to distinguish the affected hand from >>> an examiner's hand when these were placed in the patient's unaffected hand. >>> In recent years, acceptable usage of the term has broadened considerably, >>> and has been defined as involuntary movement occurring in the context of >>> feelings of estrangement from or personification of the affected limb or >>> its movements. Three varieties of alien hand syndrome have been reported, >>> involving lesions of the corpus callosum alone, the corpus callosum plus >>> dominant medial frontal cortex, and posterior cortical/subcortical areas. A >>> patient with posterior alien hand syndrome of vascular aetiology is >>> reported and the findings are discussed in the light of a conceptualisation >>> of posterior alien hand syndrome as a disorder which may be less associated >>> with specific focal neuropathology than are its callosal and >>> callosal-frontal counterparts." - >>> http://jnnp.bmj.com/content/68/1/83.full >> >> >> This kind of alienation from the function of a limb would seem to >> contradict functionalism. >> > > ? AFAICS it wouldn't even *seem* to contradict functionalism. > > >> If functionalism identifies consciousness with function, then it would >> seem problematic that a functioning limb could be seen as estranged from >> the personal awareness, is it is really no different from a zombie in which >> the substitution level is set at the body level. There is no damage to the >> arm, no difference between one arm and another, and yet, its is felt to be >> outside of one's control and its sensations are felt not to be your >> sensations. >> > > I think it is generally understood that the relevant disruption to > function is that of brain tissue, not that of the limb; hence the > references in the passage to lesions in the corpus callosum and other areas > of the *brain*. If the function of brain tissue is disrupted, then it would > be consistent to expect some concomitant disruption of consciousness, per > functionalism. >
Of course, but how is the particular disruption - that the hand appears to function normally as far as outside observers are concerned, yet there is some extra ingredient from that function which is now missing that makes it seem 'alien'. > > >> This would be precisely the kind of estrangement that I would expect to >> encounter during a gradual replacement of the brain with any inorganic >> substitute. >> > > It's clear that's what you would expect, but to infer this much, purely on > the basis of the passage you quoted, is grasping at straws. Actually it's > not even that - it's a completely unsupported inference. > You're paying attention to a part of the example that isn't relevant. If we did not know about the brain, and we sought a substitution level which only emulated the activity of the body, then something like alien hand syndrome would not be detectable from the outside (as long as the emulation chose to keep their knowledge of their condition to themselves). > > >> At the level at which food becomes non-food, so too would the brain >> become non-brain, and any animation of the nervous system would fail to be >> incorporated into personal awareness. The living brain could still learn to >> use the prosthetic, and ultimately imbue it with its own articulation and >> familiarity to a surprising extent, but it is a one way street and the >> prosthetic has no capacity to find the personal awareness and merge with it. >> > > I don't see how starting from an unsupported inference helps your case. In > fact, if you are proposing this as an example of the strength of your > position in general, it can only serve to weaken it. > Right, you don't see it. The underlying thesis of functionalism and mind-brain identity theory is that the proprietary sense of self is nothing other than function itself. To me, what AHS does is call that into question as it potentially implicates self-familiarity as a superfluous feeling which has no function. The assumption from the functionalist side has been that if we identify the correct level of substitution, we can reproduce human consciousness on any substrate, but here we see that at least the physiological (rather than neurological) level of substitution, it is possible to have a disidentification without a change in function. AHS, while not proof of neurological zombies is, like blindsight, proof of the possibility of non-functional qualia. In other words, why, in a functionalist/materialist world would we need a breakable program to keep telling us that our hand is not Alien? When you start by assuming that I'm always wrong, then it becomes very easy to justify that with ad hoc straw man accusations. Craig > David > > >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Everything List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected]<javascript:> >> . >> Visit this group at http://groups.google.com/group/everything-list. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
