question re: bandwidth/processing power of visual & cerebral cortices

[David M. Diodato]

I am interested in providing a little information on the human physiological
underpinnings which make it so much easier to extract information from an
image than from a table of data describing the image.  I recall reading
somewhere that the bandwidth of the visual cortex dwarfs that of the cerebral
cortex, and that this is the explanation.  I have read Yehouda Harpaz'
treatise on Human Cognition* and understand that 1) I don't know much about
human cognition, and 2) the processes of data acquisition and comprehension
are two different animals.

However simple-minded it may be, I seek an approximate answer to the
following question:

What are the bandwidths of the human visual and creebral cortices in, say,
Megabits/second?

I would be most appreciative of any references or answers to this question.
Thanks very much.

Sincerely,

Dave Diodato              diodato at geosc.psu.edu
Dept. of Geosciences
Penn State University

* http://www.mrc-cpe.cam.ac.uk/yh1/cognition.html