system
Given the following post, respond as if you're commenting on Reddit:
human
Is the phenomenon of 'photographic memory' real? If so what were the differences of the brain of the individual from an average individual?

If the phenomenon is real, are there perceived differences in the brain, body and behavior of the individuals that have it?
gpt
There's never been evidence of "true" photographic memory. In the sense of remembering general information in high detail for long periods of time, without the need for repeated viewings or mnemonic devices, or specialized knowledge.

But there are definitely instances of fast and highly accurate specialized memory. For example people can learn to have very good memory for sequences of numbers, words on the page of a book, sequences of chess moves, lists of names, directions, etc. But not in a general sense, and often not with one viewing. There's also hyperthymesia where people can have highly detailed autobiographical memory.

Like with the guys who could memorize chess positions immediately, and play chess without a board, would not be able to do it for nonsensical chess positions. They're effectively relying on their knowledge of sane chess moves and strategies to compress piece positions so they don't have to memorize as much to rebuild the positions with their knowledge of common chess patterns. Or with hyperthymesia it doesn't extend to stuff the person finds personally significant, and is a subconscious process. Wouldn't help for trying to memorize state capitals.

There are cases for eidectic memory which is the ability to remember a scene in exact detail for a short period of time. Which in turn would let them have more time to memorize/analyze/sketch a scene with only a short viewing.