no consciousness sans electrodes

while stanford researcher bill newsome has been talking about this for a while, he recently made public his desire to have electrodes implanted in his own brain. he wants to know the conscious experience of having (read: 'what it's like to have') one's visual decision-making affected by electrical stimulation to area MT, which is involved in motion discrimination.

this is a noble or a selfish act, depending on whom you talk to. but that issue aside, i disagree with his fundamental assertion:
"If we understand the system completely (from input to output) at a cellular level, but still do not know exactly what causes conscious mental phenomena, we will have failed."

sure, it sounds good, but there's an underlying assumption in his claim, namely, that the source of conscious mental phenomena is knowable by scientific means. let's unpack that.

1. "knowable" - whatever the causes of conscious mental phenomena, we can know them. determining what is knowable has a long history (try wikipedia's article on epistemology). many scientists and idealists believe that mental phenomena are identical to physical phenomena (we all know this as the "mind-body problem"). but there are good arguments against this, in my opinion. and, even if you don't buy my opinion, it's undeniably an unsolved issue: i'll give a shiny nickel to the first person who can demonstrate that we humans can, in principle, know all things about mental phenomena.

2. "by scientific means" - whatever the causes of mental phenomena, they can be addressed and answered by the tools of science. this amounts to scientism. simply because science has helped us to answer some questions about how the brain works, we cannot simply assume that it'll help us answer all of them. oh yeah, and all the remaining questions about the mind. don't get me wrong, i'm in neuroscience because i think it can help us answer tons of questions... just maybe not all of them.
note that it's unclear whether bill actually believes this. his interest in doing this experiment suggests that he think that the subjective experience of MT stimulation contains some data that are unmeasurable with traditional scientific tools. or he might just want someone to pay him to shock his own brain.

in the end, what will we learn from bill's experiment? well, to some extent, the experiment has already been done by penfield in the early 20th century and by many current neurosurgeons. today, recording electrodes are implanted in epileptics' brains to determine the initiation zones of focal seizures. but these can be modified to stimulate brains. additionally, neurosurgeons push on random brain parts while awake patients describe their subjective experiences. last, noninvasive, temporary brain lesions are possible with a technique called transcranial magnetic stimulation... so you can shock the right side of your brain and talk about the experience of losing all muscle control on your left side, as you try to pick yourself up off of the floor. two nickels to the sap who wants to do that experiment.

so what'll we learn? well, bill might learn something. but will it count as science? and if doesn't, will it bring us any closer to a fully physicalist understanding of the conscious brain.

in the meantime, it looks like he's still waiting for the right surgeon: "If the risk of serious postsurgical complications was one in one hundred, I wouldn't do it. If it was one in one thousand, I would seriously consider doing it. To my chagrin, most surgeons estimate the risk to be somewhere in between my benchmarks."