What is going on in our brain when we forget something? I’m not talking about the times when we are too busy or distracted to remember something… I’m talking about when we forget a piece of information that normally we know, like say, the capitol of Belgium. It’s not like the information is gone, because later you can recall it without having to relearn the facts.
Anyone? Anyone?
You give too much credit to the state of the brain sciences. We don’t really know how memories are encoded yet let alone how they are forgotten. We can say that people with a huge concussion or Alzheimer’s are likely to forget certain types of things but the details still allude scientists.
I would extend the question to other kind of memories. Some years ago, I discovered a picture of myself, maybe 3 or 4 yo holding a duck toy I had completely forgotten about. When I saw the picture, not only I remembered having been fond of the duck, but more surprisingly, and very clearly, the taste of his rubber beak (that I probably was munching on as a kid).
That’s surprised me a lot and I wondered if every memory is stockpiled somewhere and to what extend. Would I remember the feeling of a blanket if I was watching a picture of myself as a little kid lying on it? Could I remember exactly the shape of some random tree I saw while crossing the street last week if presented with the correct trigger? Is there somewhere in my brain a completely accurate picture of this tree, down to the last leaf, waiting just in case I could/would want to retrieve this information?
And indeed what happens to all these memories until something awake them?
It might be that the memory you had was a false one, constructed on the spot. Maybe it contained a kernel of truth but the brain is very good at filling out a memory with seemingly realistic details made up on the fly.
Elizabeth Loftus has done a lot of work on false memory reconstruction and managed to get many people who went to Disneyland as a child to “remember” thier encounter with Bugs Bunny there in great detail. These people would be quite adamant that they really did see Bugs and could give a huge amount of facts to support their memories, until it was pointed out that Bugs Bunny is a Warner Brothers charecter and not a Disney one.
It’s pretty widely observed that smell/taste memories are the ones most associated with emotional recall (think of Proust and his tea-soaked cookie. The fragrance awakened a whole complex of visual and emotional recall.)
My old neuroanatomy professor explained this as related to the proximity of the olfactory nerves to both the temporal hippocampal and amygdaloid structures (without which memory is shot) and to the deep limbic system (sometimes called the reptilian or “smell brain”), which is prominently developed in animals that don’t have the cortical capacity for a lot of verbal input. It’s strongly linked to emotional reaction.
This would suggest that smell memories should be more resistant to falsification; Loftus et al. used words, a cortical function, to “rewrite” visual records, while olfactory function carries on its own recording and processing.
It made sense to me. I haven’t kept up with research in this area (too much to keep up with in my own specialty!) but we probably have a neuroanatomist or neuropsychologist who knows the current state of the art.
Anybody?
Oh, there’s another structure adjacent to the hippocampus and the amygdala has a name that means “hook” but I can’t think of the freakin’ name. 