Tuesday, March 17, 2009

Fugetaboutit - the perils of memory

Why do we forget, asks an article in today's Science Times by Natalie Angier with a fun look at a couple of questions about memory.
...there are plenty of...examples of memory's whimsy and bad taste - like why you may forget your spouse's birthday but will go to your deathbed remembering every word of the Gilligan's Island theme song...
Memory comes in different flavors. The mind preserves traces of facts, events, or sequences of tasks that we perform with our body differently. Each are encoded in a different way and different brain structures are involved in storing and retrieving them. One of the more generally accepted models of memory includes a structure called "working memory" which takes something that has entered our awareness - a phrase, say - and maintains it by mentally rehearsing it over and over under its trace becomes more solidified. Later on, and much of this is thought to happen while we sleep, the brain through a fascinating volley of patterned firings consolidates that information. It actually physically changes the properties of cells when you remember something. It is generally thought that the memory of your friend's face or that great meal in the Provence isn't stored whole in one drawer but that its elements are distributed and each time that they are accessed they are re-assembled. Today's article discusses the advantage that music confers in general upon words, by adding structure. It also does a good job on why many of us cannot remember jokes but the $64,000,000 questions - why we forget that birthday... There are several reasons why, although someone's birthday is symbolically important, it is so hard to remember - 1) it is a number or complex of words and numbers that has no particular meaning, i.e. December 3rd does not mean Charlie. It just happens to be Charlie's birthday, it could just as well be any other day. So the detail of that number is small and 2) it is arbitrary, and if we want to confer upon it the association of Charlie we would have to rehearse it but 3) we heard it only one time (unless Charlie is obsessed with our remembering it). Add to that the problem called interference - there are 364 other numbers it could be and some of those numbers are other people's birthdays - so somewhere in our mind a certain subset of those 364 numbers has had importance attached to them and those numbers could be shared exactly or could include December 13 or November 3rd. Well, you get my point. There are several other differences that Charlie's darn birthday has from the words for the Gilligan theme. The theme song is not only heard repeatedly and structured by being attached to a melody, but 5) it doesn't have to come up at any point in particular, we can just remember it when we want to. Charlie's birthday has to be held in mind and then brought to surface at a particular point in time - a particularly tricky type of memory. Like thinking in the morning - I have to pick up that sweater from the cleaners on the way home from work - and then forgetting by 5:45 pm for three days in a row. Finally there is the difference between remembering something because it is obligatory versus remembering something because it's fun. 6) The obligation to remember creates pressure and neither the encoding nor the retrieval of memory work particularly well under too much of it. So the more you pressure yourself about not forgetting that birthday, the more likely it is you may forget it. Kind of irritating - huh? But now you have 6 excuses.


Anonymous said...

I have photographic memory and am extremely keen on numbers and symbols; but my short-term memory has been weakening. I wonder if that is proportional to aging. Sometimes I couldn't remember what I had for lunch or what my iPod played last.

I found memory that provokes emotion most inexorable. I wish I can push a button and delete the painful memories pertaining to past relationships.

Ted said...

Matt - A photographic memory, one day before my midterm I envy you!