I am aware that there are a number of people out there who simply do not understand why I claim that the brain actually creates the images that you see in your head and that this suggests that whatever “out there” is it may not be what you perceive it as being.
I have argued that the brain can “fill in” areas of missing information to create a continuous visual field.
Would you like proof of this?
Okay, open the image below to see it at its full size. Shut your right eye, look at the small black dot on the right with your left eye and move towards your computer or phone screen. There will be a point where the hatched square will totally disappear.
This is simply because as you get closer to the image the hatched square falls on your blind spot. This is the place at the back of your retina where the optic nerve can be found. This has no light-sensitive cells so there is no visual field at that point. To give you an unbroken visual image of the external world the brain “fills in” the information from the data it already has regarding what you are looking it. It perceives a black line above and a black line below. Not usually expecting a grey hatch-box it simply fills in the blank area with what it thinks should be there …. hence the continual vertical line …..
So if it can fill in that bit, why can’t it fill your whole visual field with things it wants you to see?
It does this all the time. Just look at the scene around you. Close one eye. Your blindspot is still there but you don’t see it. But at all times a small part of your visual field is blank. You should see this … but you don’t Just like with the continual black line, your brain “fills in” the blank area from the visual information surrounding it.
This is why perception studies, particularly studies of vision, fascinate me so much ….
