From: Robert Owen (rowen@technologist.com)
Date: Sat Dec 18 1999 - 21:26:27 MST
We must thank our friend Eugene Leitl <eugene.leitl@lrz.uni-muenchen.de>
for this timely addendum to our study of "Qualia", especially with respect
to the perception of color. Eugene's reference has been abridged, and the
complete article is found at the URL below. [RMO]
~ RETINAL STUDIES HINT AT UNDISCOVERED BRAIN AREA ~
Scientists have long argued over whether evolution devised an
efficient method of delivering images to the brain, or if more
recently evolved aspects of sight, such as the ability to see red
and green, were simply jammed into the older system.
Since 60 percent of the human brain is devoted to processing
vision, the answer could teach us much about the evolution and
structure of our brain.
Every mammal can see blue and yellow -- the colors are carried
by the same pathway -- but primates such as ourselves are the
only mammals that can see red and green. Researchers have long
thought that this ability evolved through a set of cells in the retina
simply becoming more sensitive to red and green and passing that
information to the brain down the same nerves as other visual
information.
But David J. Calkins, Ph.D., assistant professor of Neuroscience in
the department of Ophthalmology and Center for Visual Science at
the University of Rochester suggests that when some cells evolved
sensitivity to red and green light, a whole new system of neurons --
including new areas of the brain -- had to evolve as well.
http://unisci.com/stories/19994/1216991.htm
=======================
Robert M. Owen
Director
The Orion Institute
57 W. Morgan Street
Brevard, NC 28712-3659 USA
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