[From Bill Powers (2008.05.02.1945 MDT)]
Speaking of neuropsychological voodoo, I’m reminded of a thought I often
get when I see the papers relating the detection of brain activity to
perceptions and behavior. The odd thing about these papers is the
implication that finding brain activities relating to experiences and
actions is very surprising. It’s as if the authors really have no
conception that EVERYTHING WE EXPERIENCE happens in the brain. What would
really be surprising would be to have a person experience something while
an observer with the right equipment to measure brain activity saw
nothing at all happening.
Tom Bourbon, who worked for a while in a lab where brain activities were
measured using MRI equipment, pointed out an interesting fact about the
so-called right-brain-left-brain differences. He said that those
differences are found by plotting only differences of brain
activity between the left and right side, and amount to about 5 percent
of the total activity. I’m not sure (maybe someone else on CSGnet knows),
but it strikes me that the pictures we see showing those colored blobs in
the brain must also be made by subtracting the background, so it looks as
if nothing is happening in the brain except where the blobs are. Could it
be that these are also fairly minor enhancements of activity, grossly
exaggerated by subtracting out a large amount of background
activity?
When you think about it, does it make sense that the entire brain could
be quiescent, doing nothing, with only a few cubic millimeters of it
being active? How would signals get to that area, or move from it to
another place, if nothing else in the brain were neurologically active?
EEGs don’t show a brain that is ever silent (except in a corpse). Every
electrode, whereever placed, shows ongoing signals in great profusion,
changing every second. It just makes no sense to me to think that only
small volumes of brain tissue are active at a given time. The only way
that could make sense would be if you believed that perceptions are
direct knowledge of the external world obtained without the use of the
brain. And that is certainly voodoo. I think someone is scamming himself,
or us.
Best,
Bill P.