Book Review

[Scott Chesnick]

I was reading a book review that made me think of Gravity's rainbow...

...how the brain produces consciousness.What studies of brain damage reveal 
is that consciousness has many facets. But it can be a dangerous appraoch 
because it rests on the assumption that each part of the brain that 
contributes to consciouness does so consistenly over time. Yet if 
consciousness is dynamic rather than static,if the conscious functions 
performed by certain body of neurons in the brain are transcient, then the 
functions lost when the brain receives a blow at a specific point in time 
could differ from those that could have been lost a moment earlier or later.
 In the past ,scientist (there we go trusting them again) have searched for 
discrete switches at the nueronal level-singular all or nothing events which 
when put together give scensibility. But how and where the translation from 
physical to mental takes place remains a mystery, not the least because 
those on/off neuronal mechanisms seem so imcompatable with the diffuse and 
indefinable property of consciousness.The underlying physical processes are 
no less complex
and difuse than consciousness itself. Consciusness is not located in one 
region of the brain, one neuron one molecule, and does not necessarily go 
hand in hand with stimulation of the sences. But each conscious experience 
is singular in time. Shades of subtlety in the activities of neurons: they 
can be biased to respond in cerain ways.. and in sence that their behavior 
is shaped by past experience, they even have a memory. The action 
potentials, the firing...of a cell in responce to stimulation, might be an 
all or nothig event, but the threshold at which a neuron produces an 
electrical signal can be lowered or raised incrementally.
   By the same token , consciousness is better viewed as a continuum than a
all or nothing phenomenon. It is a product of large interacting groups of 
neurons which form rapidly around a triggering stimulus like ripples on the 
surface of a pond. And the size of each ripple depends upon the the nueronal 
arousal of the at the at that particular moment in time. Arousal in turn is 
controlled by chemicals called amines (neuromodulators) that are produced at 
the more primitive centers of the brain. They ooze on up from the primeval 
to the cortex and determine the depth and level of the emerging consciousness...

"Journey to the Mind" S.A. Greenfield
Reviewed by L. Spimmey
A.Scott Chesnick
IN-VIVO NMR CENTER NHLBI|LCE
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