memory

[molly]

Given that every cell in our body has a relatively short lifespan, and none of the cells are around today that were part of us as children, why then can I remember back 40 years?

[Janetex]

not every cell has a short lifespan and we do keep some cells all our lives, particularly some that we don't want, perhaps that is so with the brain or perhaps we just keep reorganising or memories.

[bluedolphin]

Yes some cells grow faster and that is the reason that chemotherapy works like it does. It attacks fast growing cells eg: your hair (thats why it falls out) and the cancer.

[j2buttonsw]

I would say all "normal" cells have a finite life and it is the cancerous ones (by definition) which don't know how to die. I guess if a memory was a neural network then so long as the constituent cells were replaced faithfully one would retain the memory.

[David H]

Various facts I've read on memory 1) Memory actually grows new nerve fibres in the brain 2) Once imprinted, no memory goes, it just gets hard to find 3) In an experiment on rats, they found whichever part of the brain was removed, they never forgot things they'd learnt, like escaping from mazes. This means memories are stored in the brain as a whole, and not just in one place. Therefore, it makes sense we never actually lose any memory. The best tool to remind is a similar word/object etc. seen, that then pops up the relevant memory for you. It works best for dreams you've had the previous night you think you've forgotten, but works the same way for all memories. Also, on friends reunited, many times I hear a memory I'd forgotten from school, and when I hear it I often recall it all, though some memories stay put.