I've got an article in the Boston Globe Ideas section on a phenomenon that's always fascinated me: the tip-of-the-tongue moment.
Late in 1988, a 41-year-old Italian hardware clerk arrived in his doctor's office with a bizarre complaint. Although he could recognize people, and remember all sorts of information about them, he had no idea what to call them. He'd lost the ability to remember any personal name, even the names of close friends and family members. He was forced to refer to his wife as "wife."
A few months before, the man, known as LS in the scientific literature, had been in a serious accident. He was thrown from his horse and the left side of his skull took the brunt of the impact. At first, it seemed as if the man had been lucky. A battery of routine tests had failed to detect any abnormalities. But now he appeared stuck with this peculiar form of amnesia, so that the names of people were perpetually on the tip of his tongue. It was agonizing.
The paradox, of course, is how we know what we don't know. If we've forgotten a person's name, then why are we so convinced that we remember it? What does it mean to know something without being able to access it?
- Log in to post comments
My initial thoughts would be that a situation like this would be either some sort complete disruption of a specific and isolated pathway. In that case, information that normally travels to several parts of the brain simultaneously (such as to other premotor and frontal cortex areas as well as to the motor cortex or cranial nerves for speech) might, in the case of tip-of-the-tongue situations, be going only to the premotor and higher reasoning areas without going to the corresponding "action" areas. Hence the person experiences the feeling of know that they should be saying something, but for some reason simply cannot.
Of course, that was just an initial thought, and during the course of writing it I realised there are all sorts of problems with it. For one, that model really wouldn't really give much explanation for why such a situation could happen to a healthy brain. Anyway, that is part of why I enjoy neuroscience... I can end up debating myself over some idle thought when I really ought to be doing work.
Oh dear, I should have proof-read more carefully... that opening sentence to my previous comment is terrible. I apologize to all who read it.
I don't know about specific mechanisms, but it certainly seems to imply that thinking of the brain as well-organized is probably a poor model. It's more like a really poorly organized set of data but with really, really fast search and linking systems. Being able to retrieve a name, an image of a face, and the sound of a voice from disparate storage locations and link them together with nearly 100% accuracy is nothing short of, well, um, what's that word again...?
Either way, good article!
I've seen similar effects happen to people I know with certain types of dyslexia (permanent) and migraineurs (temporary, induced in the pre-migraine aura phase).
this problem started plaguing me in the sixties(age)and has
worsened slightly in the early seventies.names are common
but facts(usually one word)are equally common. in most cases
the memory comes through in minutes to hours even though
i have moved on to another subject. it just pops up into my
consciousness.
Its interesting to think about it in relation to theories of knowledge and of memory. For example, if you take a network metaphor, then to remember the "name" of something your brain is being activated by knowledge about that thing, maybe sensory input as well. The network theory is limited here, because activation of particular neurons should lead to activation of the "name". Unless the knowledge has been prorammed into the brain in a certain direction...
Maybe it is something to do with sensory modality? We see, read, and hear the name of something a lot, but later can picture it, know where we saw it, who told us etc, but the connections from this information to saying the name haven't been established (or rehearsed?) in the brain?
It is a phenomenon that gets worse as one ages. It seems to have to do with remembering that you filed the information but not remembering which drawer. My aunt in her 80s in the dining room at her assisted living place has an additional problem that arises when she orders off the menu or could have the cook fix something that she likes. She was a career woman and didn't cook. My grandmother did the cooking; after she died, my aunt ate "TV dinners". Thus she doesn't know the names of dishes she likes and now it's too late to get those names on the file drawers when the cook does fix something she enjoys.
"The paradox, of course, is how we know what we don't know. If we've forgotten a person's name, then why are we so convinced that we remember it? What does it mean to know something without being able to access it?"
This reminds me of the agitation that comes when trying to make art. Many artists and writers talk about a sentence, effect, or idea being just out of reach--there but not there. The blank page (or worse, the page with imperfect sentences) is all the more frustrating because what you want to create seems at once both vividly present and discouragingly remote. That feeling of having something on the tip of the tongue is a permanent state with artistsperhaps it is a motivator?
Here's a related but different problem that apparently has to do with losing the cross-referencing between your file drawers or piles of papers as you age. I have a bottle of chlorox in the house and know that it disinfects and takes out stains in coffee mugs and clothes. I use it mostly for the latter task. But yesterday after the pump in our water well was replaced and the well itself was disinfected with chlorox, I was surprised to I find myself asking about the reminder card which said : "Do not cook, drink, or wash dark clothes with your well water for at least three days or until the chlorine smell is undetectable". "Why not wash dark clothes I asked?" When the repairman said, " because it will bleach your clothes", I thought "well, duh! I know that" but apparently couldn't get there from the disinfecting drawer.
This condition is called Dysnomia. This article was particularly interesting to me since this injury actually happened to me -- subdural hematoma and arachnoid hematoma and several fractures in my skull due to a blow to the left side of my head. My symptoms were not as bad as the guy they mentioned in this article, but this problem is still very frustrating. It was very bad for a few months after the accident. I gradually got better, but not perfect. The article also makes a good point about noting that it's not a problem with MEMORY, but a problem with RECALL.
I also often have better luck if I try to recall someone's full name. Mnemonic tricks for recalling names are almost useless in a social situation. If I bump into an acquaintance there is always that long, awkward pause... I recognize them instantly. I know who they are, but not their name. I compensate by never greeting people by name.
In reading this very interesting article in the Globe I made the connection between the way the brain stores "file fragmentations" strangely similar to the way a computer disk operates. Which poses the question of how we defragment our brains for faster recall of pertinent, related pieces.
thanks.