[sazr (OP)]

The brain receives alot of visual information some of which is redundant visual information. I am imagining it like the brain receiving a 1000 pixel wide by 1000 tall image of a road. The brain has received 1,000,000 bits/pixels of information. I am assuming the brain doesn't need all that information in order to detect the road in the image and localise where in the image the road is. But correct me if I am wrong here.

So the brain must be culling information? Removing irrelevant information? Doing some other efficient processing to only look at N pixels not all 1 million right? Can you inform me on what sort of things its doing here to efficiently handle all 1 million bits of information?

[evan_au]

The retina does an incredible job of data reduction - the retina is an outpost of brain tissue, in the eye.

In daytime, we rely on about 7 million cone cells (per eye), each able to respond to about 25 changes per second, or around 350 Megabits per second.

Through about 7 layers of nerve cells, this is reduced to a very low data rate on the optic nerve - I have seen estimates between 0.1 Mbps and 10 Mbps per eye.

It does this by having layers of cells which detect edges, and movement in certain directions.

I have also heard that the types of visual effects that the retina is most sensitive is determined by the visual environment in which you grew up - I have heard of experiments where chickens were raised in environments that had only vertical lines and lacked horizontal lines!

See: https://en.wikipedia.org/wiki/Retina
https://www.eurekalert.org/pub_releases/2006-07/uops-prc072606.php

The brain as a whole is even more complex to analyse, as it has more layers of cells, with less definable functions - and less tied to the part of an image presented to it.

[RD]

[chris]

Lovely example of the changing street, @RD