I think my personal view is different regarding how consciousness/perception and eye/brain arise. And I am aware that views are just views - a source of clinging. So, for now instead of focusing on about how something happens let us focus on what actually is happening now at this moment.Kim OHara wrote: The difference between (3) and (4) is that (3) is a function of the eye and its associated brain cells while (4) is a function of the brain, operating on (3). Without (4), we would see the two shades as being the same - just as a machine, or a naive viewer who didn't understand tiles and shadows, would see them.
What actually happening for me at this moment when I look at the image is: a darker square A and a lighter square B - that is actually undeniably happening - vividly shining perception in the light of consciousness - and the fact that that is happening is not an illusion.Kim OHara wrote: As you realise, we aren't normally aware of this extra step because it is automatic and one of the functions (and fun things) about illusions is to bring to consciousness the way our perceptions work.
Now the question may arise: isn't the square A and B are reflecting the same frequencies (& brightness etc.) of light? Yes, when you measure you will find that the frequencies (& brightness etc.) are the same.
If they have the same physical information aren't they of same color? No, the perception of color is not the same as physical information. The original question was: are squares A and B of the same shade of grey or different? The question was not whether the physical information behind the colors was the same or different.