Vision - Eye patching has been shown to stimulate the contralateral hemisphere.

Author

Eye patching has been shown to stimulate the contralateral hemisphere.

Dave R

2005-03-23, 5:39 pm

Eye patching or 'Eye dialogue' has been used in alternate health since
at least the 1980's to provoke supposedly different hemispheric
awareness and memory, to the point that some people reveal two rather
conflicting personalities.

Recent research is beginning to suggest how this might be possible.

http://brain.oupjournals.org/cgi/co...full/125/9/2023

"The results suggest that monocular viewing is associated with
preferential activation of attentional systems in the contralateral
hemisphere, and that the right hemisphere (at least in right eye
dominant subjects) is biased towards far space. Finally, the results
suggest that the poorly understood phenomenon of eye dominance may be
related to hemispheric specialization for visual attention."

andrew Judd

2005-03-24, 12:28 pm

dave_rogers4@hotmail.com (Dave R) wrote in message news:<30e9ff5c.0503221841.165fede0@posting.google.com>...
> Eye patching or 'Eye dialogue' has been used in alternate health since
> at least the 1980's to provoke supposedly different hemispheric
> awareness and memory, to the point that some people reveal two rather
> conflicting personalities.
>
> Recent research is beginning to suggest how this might be possible.
>
> http://brain.oupjournals.org/cgi/co...full/125/9/2023
>
> "The results suggest that monocular viewing is associated with
> preferential activation of attentional systems in the contralateral
> hemisphere, and that the right hemisphere (at least in right eye
> dominant subjects) is biased towards far space. Finally, the results
> suggest that the poorly understood phenomenon of eye dominance may be
> related to hemispheric specialization for visual attention."

Dave

This is an amazing article. Thanks!

If this is true then it could be possible that amblyopia is related to
the patching effect that a better seeing eye is always giving the
opposite hemisphere. So that over time it preferentially turns on one
hemisphere at the expense of the other. You would then think that
just such an opposite patching regime might help amblyopia but this is
thought to be only true in children. However it has been
suggested/claimed that a more aggressive intervention at the level of
the brain and learning can overcome amblyopia even in adults. What
is known is that if the good eye is lost in an adult the amblyopic eye
always makes some form of recovery. So its clear there is no hard
and fast rule for two eyed adults

Also astigmatism and strabismus seem possibly candidates for this kind
of interpretation. If what the eye sees, can stimulate prefentially
one half of the brain, then it follows that the perceptions of one
half of the brain can preferentially stimulate one eye. And therefore
conflict in perceptions could lead to subtle conflicts in the
movements of the eyes as suggested by Roberto Kaplan OD and others.

Are you aware of MRI studies on amblyopia strabismus astigmatism and
so forth?

This is a hugely complicated area. Whatever biases might be in
operation when patching is done its clear that these effects are only
biases and very subtle effects. For example no person ever sees the
difference between their two hemi fields in one eye - its completely
seamless - even if they have different colour vision in each separate
eye.

However Fred Schiffer MD a harvard psychiatrist has used eye patching
to reveal different perceptions and memories (admittedly using a more
complex hemi field patch) but I have found that an ordinary patch has
the same effect for some people in a startling manner as if two
personalities are revealed.

Sooner or later this kind of stuff is going to come together in a
bigger picture sense so that all the conflicting pieces of information
makes perfect sense!

Andrew

dave_rogers4@hotmail.com

2005-03-24, 12:28 pm

andrew Judd wrote:
>
> If this is true then it could be possible that amblyopia is related
to
> the patching effect that a better seeing eye is always giving the
> opposite hemisphere. So that over time it preferentially turns on
one
> hemisphere at the expense of the other.

Andrew

I find your hypothesis interesting but I cant see the evidence to
support it at this stage of the game.

MRI scans do show normal eye versus amblyonic/strabismic eye
differences but they appear equally on both sides of the brain.

http://bjo.bmjjournals.com/cgi/content/full/85/9/1052

It is true that there may be two forms of amblyopia, only one of which
developes prior to critical brain development in infancy, so its
possible, in at least come cases better vision might be possible in
adulthood via some method.

I am not sure its possible to say 'all amblyonic eyes get better' if
the normal eye is lost. Do you have a reference to support that?

However what you are suggesting is interesting and I would not rule
anything out in the light of what is now being learnt about the brain.

Dave