Black and white involves luminance pictures rather than chrominance pictures. Luminance only pictures do not get sent to the brains visual lobes for interpretation but instead to the part of the brain that unravels abstractions; a very rich mental experience compared to the mere naming of subject matter.
Thanks for this. I've just spent the past half an hour googling about it, and it's a fascinating area of study.
Luminance gives us our "perception of reality" instead of color. This is connected to the same area of the brain that allows some people who are blind from visual cortex brain damage rather than blind from eye damage to walk around without a cane, but also without bumping in to things. They can't "see" stuff, but they can tell it is present.
This was also the centers of perception that Picasso - genius or madman, you decide - exploited with the blue phase. Everything was the same color, like a cyanotype, but different luminance.
This is going to keep me busy for a while.