How Does The Brain Percieve Gray Light

[ber55ber55]

I understand how we see black and white. It has to do with the on/off functions on the bi-polar retinal cells. But how do we see gray. This isnt really a homework question, but a thought question that was given to us my our professor.

 

I am assuming it has to do with the fact that the on bipolar is not ALWAYS on and the off and not ALWAYS off, so sometime there will be two off or two on. let me know if im correct or close, or totally off. Any help would be greatly appreciated. Thanks for the help in advance

 

Alex

[iNow]

Hi Alex,

 

I'm a little confused on your question. Are you aware that there are different types of receptors in the eye, the cones and the rods? The rods are "on/off" and are more located in the periphery of the eye (on the sides), and are more specific to detecting movement (shadows and light/dark shifts). The cones are what allow us to see color, and gray is just another combination of colors.

 

Here's a sight on seeing gray:

 

http://lib.stat.cmu.edu/scgn/v51/section1_6_0_1.html

 

 

I may have misinterpreted your question, but either way, here's a few nice little references to how the human perceives visual input. Enjoy.

 

http://serendip.brynmawr.edu/bb/neuro/neuro00/web1/Patel.html

http://www.cc.gatech.edu/classes/cs6751_97_winter/Topics/human-cap/senses.html

http://web.mit.edu/bcs/schillerlab/research/A-Vision/A3-1.html

 

 

 

 

 

[ber55ber55]

First...my mistake....i am talking strickly in the vertebrate eye.

 

In vertebrates...light does not excite....and in the dark..Glu is released....but not in light

 

I do understand that we see other colors as well, but how?

 

What are these on off cell actually doing?

 

Thank you for those website though, they are still extremely helpful in better understanding the concept of vision in general.

 

Im not sure how to explain my question. The professor also told us not to think so much about the light and color....but more about AP's and EPSP's and synapses and so forth, so that kinda threw me off.

 

Thank you for your help though