There are all sorts of complex geometrical patterns, very symmetrical, some of them looking like the finest doily. … Patterns like this tend to appear in migraine, but they may also appear with fever. They also appear with various drugs. They may also be seen as one is falling asleep, and one can’t help comparing them with various forms of ornamental art and cave art, and wondering whether individuals or cultures have been inspired by some of these patterns which are built into the nervous system.

Oliver Sacks on how visual migraines may have inspired ancient pattern art. Sacks’s new book, Hallucinations, is out today, a follow-up to his fantastic 2010 The Mind’s Eye.

(via explore-blog)