Locked-In Syndrome and PVS

Locked-In Syndrome and PVS: Implications for Brain = Behavior

During our first few class sessions, I became very intrigued by the brain = behavior idea and the I-function. I kept searching for what I thought to be an easy way to approach these complicated issues. We discussed extensively the example of Christopher Reeve, as someone with an intact I-function, but who has lost a certain element of connectedness between total I-function control and his actual body. I became very interested in how the I-function and brain = behavior interrelate. I thought that looking into some information about the persistent vegetative state and the locked-in syndrome would yield a satisfying and definitive answer once and for all. Is a brain still a brain without the I-function? I found no definitive answer, but I was able to convince myself of the "less-wrongness" of the brain = behavior idea.

I first looked into the persistent vegetative state. Below I have reproduced a somewhat technical explanation of how PVS patients are believed not to have an I-function:

Three lines of evidence suggest that PVS patients are "noncognitive, nonsentient, and incapable of conscious experience [12]." First, motor and eye movement, and facial expressions in response to stimuli occur in stereotyped patterns rather than learned reactions. Second, positron emission tomography reveals cerebral glucose metabolism at a level far below those who are aware or in locked in states. PVS levels are comparable to those in deep general anesthesia and as such are totally unaware and insensate. Third, neuropathological examinations of PVS patients show "lesions so severe and diffuse [12]" that it would be almost impossible, giving our current understanding of neural an...

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...ior of persons with PVS or in a locked-in state. I know believe that even in patients who are vegetative or locked-in, brain does equal behavior regardless of I-function status.

References:

1)UPENN bioethics site

http://www.bioethics.upenn.edu/

2) independent patient resource site

http://www.geocities.com/HotSprings/Oasis/2919/

3) The Locked-In-Syndrome by Philippe Van Eeckhout.

http://alis-asso.fr/

4) medical summary of conditions and examinations, E. Valenstein & S. E. Nadeau.

http://www.medinfo.ufl.edu/year2/neuro/neuroexam/v221.html

5) Use of an Eye-Operated Eyegaze Communication System in Locked-In Syndrome, by: James E. Chapman, M.D.

http://www.eyegaze.com/doc/csun91.htm

6) Results and Reflections on the Boundaries of Consciousness, Niels Birbaumer.

http://www.psychol.uni%3Cbr%3E-giessen.de/abteil/klinisch/ascc/sils00/tuebing00.pdf