Brainz

I'm enjoying the very readable The Tale of the Duelling Neurosurgeons by Sam Kean, although I'm puzzled by the lack of duelling neurosurgeons. What keeps striking me, in Kean's tales of skull porridge gone wrong and what they tell us about how the brain works, is how specialised it is. It's easy to think of human intelligence as Intelligence, some sort of benchmark for all possible consciousness, and yet chunks of our brain are tuned to perceive the human face, and human hands. The most common "category deficit", where brain damage removes the ability to recognise just one type of thing, is an inability to recognize animals. OTOH perhaps all brains would evolve to detect something as basic and important as movement (apparently we can only see stationary objects by moving our eyes over them).

Also interesting: competing theories of synaethesia. The one I knew was that, as the brain is sculpted in childhood by the pruning of excess links, some of those links are accidentally left in place -- in my case, connecting letters, numbers, and music to colours. The other theory, which fits the effects of drugs like LSD, is that rather than being pruned out, the extra links are chemically inhibited; and that in a synaesthete's brain, those "underground channels" are not being inhibited.