and another "As a neuroscientist, I can tell you this article is based on junk science. It?s very amateurish given that it?s from a neurosurgeon, but I suspect that?s the only reason it?s getting so much attention in the first place. So let me point out two very flawed assumptions in this article:
- that his neocortex could have been ?simply off.? The way it?s stated, it?s nonsense. If his neocortical neurons were ?stunned to complete inactivity,? then his neocortex would have died (which it didn?t, evidenced by this article). It?s a fundamental fact of neurobiology ? if neurons don?t fire, their axons retract, and then they die. This happens in a matter of hours. Moreover, deprive neurons of the ability to metabolize, and they die in a matter of minutes (think suffocation ?> brain damage in about 6 minutes).
What the author means to say is that his brain was suppressed to a very low level of metabolic activity (in an MR or PET scan, this looks like a dramatic decline in activity, but this isn?t something you can see in a CT scan showing the extent of meningitis, so that reference seems like a bizarre attempt to sound credible). Anyway, some might call that being ?shut off?, but make no mistake ? biologically, it?s not at all the case. Even doctors make this mistake, but a neurosurgeon should know better.
- that either consciousness resides in the neocortex, or it must be outside the body. Consciousness involves the whole brain (neocortex, subcortical nuclei, thalamus, midbrain structures, etc.), not just the neocortex, which the author mistakenly identifies as being the ?human? part of the brain (virtually all mammals have it; elephants have more than we do). Kids who grow up without a cortex have lived as long as twelve years old and experience a very rich consciousness.
Consciousness can be altered much more dramatically by lesioning SUBcortical structures than by lesioning the cortex. Deficits in consciousness caused by cortical lesions can be RESTORED by specific subcortical lesions (look up ?sprague effect?).
Lastly, we?ve known for nearly a decade now that many people in a persistent vegetative state DO show low levels of intrinsic brain activity, and specific activity in response to emotionally salient stimuli (hearing family tell stories, etc.)
Conclusion: This article is marshmallow fluff. His cortex wasn?t off, and it?s not the only thing that gives rise to consciousness anyway. So don?t accept amateurish claims like ?my cortex was turned off but i still felt stuff so god exists.? Consciousness is an undending puzzle, but this ain?t the magic piece!"
This guys is pretty much getting torn apart in the blogosphere amongst the neuroscience community