Hitting head, seeing stars

Diane Pritchatt diane at bnclib.demon.co.uk
Fri Oct 18 04:15:25 EST 1996


Some of our staff were doing some research into making a visual cortex
stimulator for the blind at one stage.  It was explained to me that the
'stars' or spots were caused by chemicals called phosphenes.  Perhaps
you could look into that further?
Diane

In article <544tfg$7fk at highway.leidenuniv.nl>, Jeroen Schaap <Schaap at rul
lf2.medfac.leidenuniv.nl> writes
>In article <v01540b00ae8b75cfde51@[192.197.250.46]>,
>   steven at MSHRI.ON.CA (Robert Steven) wrote:
>[snip]
>>I know that the neurons in the eye are capable of responding to a 
>physical
>>stimulus. If you poke your eye in the right place, for example, the 
>neurons are
>>stimulated and you will see a spot in your visual field. So I guess if 
>you
>>bang your head you could just be physically stimulating the neurons in 
>your
>>eyes. Or
>>maybe the neurons in the visual cortex are physically stimulated by a 
>hit to the
>>head resulting in the perception of spots or stars in the visual field.
>>
>>Could also involve blood flow. Transient restrictions in blood flow (to 
>the
>>brain? or retina?) will generate spots before your eyes.
>>
>>Sorry no references.
>>
>[snip]
>>-Rob Steven
>>
>>
>
>Another idea, Oliver Sack researched aurea's during migraine attacks. So 
>it is possible that with a head bang you temporarilly deprive your 
>visual cortex of input after which this areas go and generate 
>chaotic-like patterns. 
>
>I have no refs for Sacks; I've only seen some tv-interview (extensive) 
>on dutch television and I have the dutch text of these interviews. 'Een 
>schiterend ongeluk' from 'uitgeverij Contact'.
>
>Daniel Dennet has a certain point of view, that is 'vision-demons' just 
>go on with making 'pictures' and as a result you see stars; it's not 
>exactly what he is saying, but you may extract this from his story. 
>Sorry, it's a time ago I've read it. But the title is: 'Consiousness 
>explained'.
>
>Jeroen

-- 
Diane Pritchatt



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