Page 82 - Darwin's Dilemma: The Soul

Darwin’s Dilemma: The Soul

Who Observes the Visual Images in the Brain?
W h o O b s e r v e s t h e V i s u a l I m a g e s i n t h e B r a i n ?
After the light from an outside object falls onto the retina, sig-
nals are transmitted to up to 30 different visual centers in the brain
for processing. The light passing through the lens at the front of the
eye leaves an upside-down and two-dimentional image on the lay-
er of retinal cells at the back of the eye. Following various chemical
processes, the rod and cone cells there convert that image into elec-
trical impulses, which signals are transmitted by the optic nerve to
the vision center at the rear of the brain. The brain then assembles
these into meaningful three-dimensional images.
In the words of Craig Hamilton:
How that happens is an example of what is known as “the binding
problem” and is itself a mystery that no one has yet solved convinc-
ingly. For the moment, though, what is important to understand is

Light passing through the lens produces a reversed and upside-down image on
retina at the back of the eye. The rod and cone cells there convert that image into
electric currents, which are forwarded to the visual center at the rear of the brain. The
brain then converts the signal into meaningful, three-dimensional images.

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