Richard L. Gregory’s book, Eye and Brain, has been one of my favorite since coming across its first edition in high school in 1966. My father had very few books in his optometric library, but this was one of them. Here is Sir Richard still sharp into his 80s (he died at age 86 in 2010) introducing the motive for his writing Eye and Brain, and pay close attention to his splendid description of the discussion that goes on with oneself in the process of writing:
In the 2015 Princeton University Press Edition (p.53) Gregory writes:
“The retina has been described as an outgrowth of the brain. It is a specialized part of the surface of the brain which has budded out and become sensitive to light. It retains typical brain cells which are functionally between the receptors and the optic nerve (but situated in the front layers of the retina), and greatly modify the electrical activity from the receptors themselves. Some of the data processing for perception takes place in the eye, which is thus an integral part of the brain.”
That is worth emphasizing: Some of the data processing for perception takes place in the eye, which is thus an integral part of the brain, which has profound implications, particularly in binocular fusion, acquired brain injury, and degenerative processes such as AMD. This leads to a very special trivia question, the significance of which remains under-appreciated despite our best efforts to advance this knowledge:
Q. What structure represents the outermost part of the brain?
A. The retina.
So in Sir Richard’s memory, let’s once and for all dispense with the notion that the eye and the brain are separate entities that get together whilst having tea. Let us speak instead of the retina and the rest of the brain, as if we really believe that retina is brain tissue.
In Sir Richard’s honor, permit me to share with you a few more of my favorite clips from this Welcome Trust production.
Gregory on early influence in philosophy from Bertrand Russell:
Gregory on the influence of cognition in sight restoration:
Gregory on the Kanizsa Illusion:
Gregory on Bayesian Probability and Perception: