[From Bruce Abbott (961022.1250 EST)]
Hans Blom, 961022b --
(Bill Powers (961015.1415 MDT)
I was surprised, I remember that -- almost as surprised as I was
when I read that 25% of the nerve fibers in the optic nerve carry
_efferent_ signals.
Physiology says that the retina is part of the brain.
I wouldn't be surprised to find efferents to the retina itself (for, e.g.,
contrast control), but why the surprise? Wouldn't some (perhaps all) of
those efferents be involved in control of lens-shape (accommodation; control
of focus) and pupil diameter (control of brightness)?
Regards,
Bruce
[From Bill Powers (961023.0745 MDT)]
ยทยทยท
At 12:49 PM 10/22/96 -0500, you wrote:
[From Bruce Abbott (961022.1250 EST)]
Hans Blom, 961022b --
(Bill Powers (961015.1415 MDT)
I was surprised, I remember that -- almost as surprised as I was
when I read that 25% of the nerve fibers in the optic nerve carry
_efferent_ signals.
Physiology says that the retina is part of the brain.
I wouldn't be surprised to find efferents to the retina itself (for, e.g.,
contrast control), but why the surprise? Wouldn't some (perhaps all) of
those efferents be involved in control of lens-shape (accommodation; control
of focus) and pupil diameter (control of brightness)?
It's my impression that all ocular motor functions are driven by signals in
other pathways, outside the optic nerve. I think those efferents in the
optic nerve must be doing something to the retinal perceptual systems. What,
I can't imagine.
Best,
Bill P.