Blind Man Sees with Third Eye.
www.npr.org
The case involves a middle-aged male physician living in Switzerland, who is known only by the initials "TN." A few years ago, TN had two
strokes, one on either side of his brain. The strokes severely damaged the part of the brain primarily responsible for vision, known as the occipital
cortex
(visit the link for the full news article)
Here is a bunch of science talk that seems like greek to me, concerning this subject but Not having to do with this specific experiment but studies in
Cybernetics.
Experience with moving visual stimuli drives the early development of cortical direction selectivity
Ye Li1,4, Stephen D. Van Hooser1,4, Mark Mazurek1, Leonard E. White1,2 & David Fitzpatrick1,3
Department of Neurobiology, Duke University School of Medicine,
Department of Community and Family Medicine, Doctor of Physical Therapy Division, Duke University School of Medicine,
Duke Institute for Brain Sciences, Duke University, Durham, North Carolina 27710, USA.
These authors contributed equally to this work.
Correspondence to: David Fitzpatrick1,3 Correspondence and requests for materials should be addressed to D.F. (Email:
[email protected]).
Top of pageThe onset of vision occurs when neural circuits in the visual cortex are immature, lacking both the full complement of connections1, 2 and
the response selectivity that defines functional maturity3, 4. Direction-selective responses are particularly vulnerable to the effects of early
visual deprivation, but it remains unclear how stimulus-driven neural activity guides the emergence of cortical direction selectivity. Here we report
observations from a motion training protocol that allowed us to monitor the impact of experience on the development of direction-selective responses
in visually naive ferrets. Using intrinsic signal imaging techniques, we found that training with a single axis of motion induced the rapid emergence
of direction columns that were confined to cortical regions preferentially activated by the training stimulus. Using two-photon calcium imaging
techniques, we found that single neurons in visually naive animals exhibited weak directional biases and lacked the strong local coherence in the
spatial organization of direction preference that was evident in mature animals. Training with a moving stimulus, but not with a flashed stimulus,
strengthened the direction-selective responses of individual neurons and preferentially reversed the direction biases of neurons that deviated from
their neighbours. Both effects contributed to an increase in local coherence. We conclude that early experience with moving visual stimuli drives the
rapid emergence of direction-selective responses in the visual cortex
[edit on 24-12-2008 by Bruiex]
[edit on 24-12-2008 by Bruiex]