Friday, August 11, 2017
How does this work?
Common observation: When I'm short on sleep, all sorts of immune mechanisms and damping mechanisms are weak. Negative feedback fails. Lots of people have noticed and described this in lots of ways. Cult leaders and military trainers use this fact intensively.
Looking specifically at the optical system. Normally the brain has a sort of spatial noise-canceling system that hides the flaws in the retina. When sleep is short the AVC doesn't counteract the flaws, and I see all the sunburns and laserburns accumulated through the years.
How does this noise-canceler work? It's clearly operating way up in the cortex, in an area where the retinal image is rebuilt.
Raw retinal image with burns: (The big slash at lower left happened about 4 years ago when I STUPIDLY looked at the bottom of an optical mouse while trying to clean it. Tip: DON'T DO THAT!)
Up in the rebuilding department, the brain forms a mask from the burned spots. It distinguishes them by a lack of change. Perhaps the mask is a sort of 2-dimensional capacitor, building up more neural charge where the signal is not averaged out by changes. (In other words, a semi-permanent template.)
And then fills in the mask with the details that belong there, acquired by moving the eyes around (saccade).
Finally the filled-in mask is superimposed on the raw image:
Undoubtedly the real mechanism is infinitely more complex, but this is at least one stylized model.
Up in the rebuilding department, the brain forms a mask from the burned spots. It distinguishes them by a lack of change. Perhaps the mask is a sort of 2-dimensional capacitor, building up more neural charge where the signal is not averaged out by changes. (In other words, a semi-permanent template.)
And then fills in the mask with the details that belong there, acquired by moving the eyes around (saccade).
Finally the filled-in mask is superimposed on the raw image:
Undoubtedly the real mechanism is infinitely more complex, but this is at least one stylized model.
Labels: Asked and sort of answered, Grand Blueprint
¶ 8:33 AM
