RE: TECH: Cat eye video camera???

From: Ben Houston (ben@exocortex.org)
Date: Sat Mar 10 2001 - 22:10:42 MST


Hi "Zero Powers",

This was also done last year as well. I do not know which university you
are referring too but I believe that some researchers in the US did the
following:

First they immobilized the cats in an apparatus that fixed their gaze at a
very large wall projector. They removed the cerebral cortex of anesthetized
cats in order to expose the lateral geniculate nucleus of the thalamus. The
LGN of the thalamus is a quick stop over location between the retina and the
visual cortex - a low-level visual processing area if you will. They then
presenting calibration stimulus to the cat while recording the neural
activity in the LCN. From this procedure they were able to determine the
visual information conveyed by the LGN neural firing. It is important to
note that the calibration was basically determining the type of
center-surround class (on-off or off-on) and the involved colors (<-- I'm
not sure about this) as well as the respective receptive field (ie. size,
orientation). It is the ganglion cells in the retina that give rise to the
axons that innervate the LGN. I believe they used ellipsoids to represent
the receptive fields. After this calibration they were able to reconstruct
arbitrary visual stimulus from just the neural firing - thus you have
created a cat-mediated video camera.

In this old presentation of mine I have some reconstructions of scenes of
the original cat-video camera:
  http://www.exocortex.org/~ben/augment-draft.ppt

Cheers,
-ben houston
http://www.exocortex.org/~ben

-----Original Message-----
From: owner-extropians@extropy.org [mailto:owner-extropians@extropy.org]On
Behalf Of Zero Powers
Sent: Saturday, March 10, 2001 3:02 AM
To: extropians@extropy.com
Subject: TECH: Cat eye video camera???

I heard a short piece on the radio today about some researchers (in the
U.K.?) who had successfully attached wires to a cat's brain and by recording
the signals in its brain had recreated discernable images of what the cat
sees on video. I can't find anything about it on the net. Anybody here
know anything about this?

Thanks.

-Zero

Learn how your computer can earn you money while you sleep!
http://www.ProcessTree.com/?sponsor=38158
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com



This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:59:40 MDT