Image processing

[Zolar V]

When light travels through the eye and excites the rods and cones, which in turn excites certain nerves depending on the wavelength of the light, how is the image produced received by the brain? Are the messages taken from the optical nerve received by a singular processor in the brain? or is it broken up into many processes/areas?

[Externet]

Nobody has a clue on the mystery. Not even a remote guess on how it works. Perhaps in a couple of hundred years, perhaps.

[John Cuthber]

We are not quite as clueless as Externet thinks, there is some information on the matter. For example there is evidence that, somewhere in the brain, there are neurons that spot horizontal lines and others that recognise vertical ones.

[Mr Skeptic]

I think some pre-processing is done along the optic nerve as well. The study of optical illusions gives some clues as to the overall processing.

[Zolar V]

looks like i have a potential study awaiting me once i get out of the air force and onto better things. like college and research.. mmmmm research.. mmmmm

[CharonY]

There is quite a large part known about that. Actually the processing starts almost immediately after the sensory cells before it even reaches the brain (though technically eyes are part of the brain, of course). A classical textbook example is the contrast enhancement by having lateral inhibition. So whatever reaches the primary visiual cortex is already partially processed. In the visual cortex the areas responsible for the detection of special patterns (as John mentioned) are located. The way how neural conncections can account for the signal modulationis quite fascinating and there is a whole lot around in regular textbooks. I am also pretty sure that there are also pretty good ones for laymen around, if you are interested.

[ewmon]

I have read that different areas of the visual cortex process different visual information (color, shape, motion) and that the brain then combines this information to form our complete perception of vision.

[CharonY]

Yup indeed. Different areas in V1 have specialized to react to specific signals. Note that at this point every signal is transduced to action potential patterns. That is, the image the brain reconstructs is dependent on which brain areas got stimulated, rather than due to the nature of the signals themselves.

[Zolar V]

Relating that type of separation between processing stages of a given item, is it faster and could it be applied to computer processing?

[EdEarl]

by Jeff Hawkins sheds some light on the topic.