Talk:A.I. by Gjeremy

Possible answers to your questions.

* Given that eidetic memory does exist, "Why don't we all have eiditic memory"?

We don't need it. The best theory for memory I've heard is that it's not meant as perfect record of the past. It's merely there to provide enough information about past events so that we can predict the future and make decisions based on these predictions. Some people possess whats coined as "photographic memory".

Those with photographic memory are either in two categories. Those that use memory techniques (eg linking lists to stories to help retreival, which is just a practiced skill), and those which don't have a input filter. We all have a filter that stops us focusing on everything, it filters out whats important and ignores what isn't. Most, if not all, of those people without the filter, are driven insane by the copious amounts of data and they can't handle it, essentially retreating from the world (This could be a possible link to illnesses such as autism).

* Why are our brains all in one place, and not distributed through the body?

It's an organ. Evolved out of a need for a central executive to make decisions. However most neurons, especially those concentrated in the spine, can perform complex computations independant of the brain. An example of this is autonomous reflex.

* Can DNA store memories, and if so, how much information can one cell hold? DNA doesn't hold memories, it holds blueprints needed when building and repairing a body. When a cell repairs itself, it refrences the dna. DNA is estimated to be about 1 gigabtye. A cell contains 6 billion base pairs. That's 6 billion gigs.

Memories aren't stored like data, instead - pathways are layed down between neurons, things are re-arranged. Each time you access a memory, you're actually reconstructing the memory from scratch, so the memory is different each time. Each time you make new memories, you're subtely altering the old ones. I'm sure you've had times in your life where you've sweared you remembered something a certain way, but you ended up being wrong. This is because the memory has been reconstructed, and if theres information missing, your brain fills it in with a best guess. So you see, dna could never store memories, dna storage is precise (like a computer), memories are messy and reliant on the brain. They're totally different storage mechanisms.

This does lead to an interesting question of genetic memory and instinct. Instinct is something encoded in the dna, like a base program. For example, birds that fly south during winter survive; evolutionarily this trait has become dominant through selection. It may look like memory, but its really just a instinctive behaviour, like seeking food and water. I don't think true genetic memory exists - you won't remember what your grandfather did on his 16th birthday.