It feels like the brain is slipping, losing its footing, tumbling through vacant nothingness. Having a word on the tip of one’s tongue is a unique kind of discomfort.
Scientists have been studying the phenomenon for over half a century. The scientific term for it is lethologica, from the Greek “lethe” (meaning “forgetfulness”) and “logos” (meaning “word”). Lethologica can occur in relation to names, words, locations, dates. What’s happening in the brain at this time?
Roger Brown and David McNeill, psychologists at Harvard University, conducted what is widely considered to be the first empirical research in this area, in the 1960s, and found that a key element of this state is the sense of partial recollection.
It’s not that you don’t know the word; it’s that you can’t remember it in its entirety. So, a guessing game begins in the brain. And one ends up saying things like: “It’s a funny-sounding word, but it’s not funny”; “It has a punch to it”; “I think it starts with an f and has three syllables?”
The problem, of course, is that the f turns out to be somewhere in the middle; the number of syllables is off. “Why do I always do this,” you might say in exasperation. Of course, it’s not just you.
The symptoms of lethologica are startlingly universal, down to the nature of the guesses and the escalating exasperation. Dig a little deeper and the really interesting questions emerge: Why does the brain do any of this? Why not just admit defeat and go, “No, I can’t remember”?
A recent study by psychologists at Colorado State University (published in the Journal of Experimental Psychology: General in September), offers some interesting clues.
For their study, the researchers conducted six experiments with batches of about 53 students each, from the university. The students were given 80 general knowledge questions, to be answered in one word each.
When the question or statement was unfamiliar and the answer was a simple “I don’t know”, there is typically no sense in the respondent’s mind that they might know the word.
It was when the question or statement was familiar, and the answer tucked away somewhere in the respondent’s brain, that lethologica struck.
As the correct response eluded it (as will happen, from time to time, with any complex memory system), the brain appeared to cast about, increasingly desperately. First letter; number of syllables; length of word; similar word.
Studies, over time, indicate that only about 36% of those who guess the first letter during a spell of lethologica get it right. About 60% of those who guess the number of syllables get this detail correct.
Why would this be? Why does the brain offer these clues at all? The Colorado report seeks to explain this by drawing a parallel between lethologica and another memory experience: déjà vu.
Now, how do we “know” anything? The human mind functions by creating associations. These associations create a sense of familiarity (“I know this”; “I’ve done this”), which satisfies a deep human need for sense-making.
But sense-making and connection-building are not a flawless process. One explanation for déjà vu is that it is the mind’s tendency for confabulation, gone awry. The sense of “I’ve been here” or “I’ve seen this” conjured in a context where that is simply not true. (Another explanation, of course, is that we live in a simulation and déjà vu is a glitch in the matrix.)
With lethologica, confabulation results in conjured cues. In a tizzy of attempted sense-making, the brain misfires on all cylinders.
As the tizzy dies down and the person moves on to other things, the brain keeps working on the problem in the background, as brains tend to do. And the answer is usually found, or the problem eventually “forgotten”.
In summary, then, lethologica isn’t really a word on the tip of the tongue. It’s a word lost, for the time being, in a haze. The brain doesn’t like “lost in a haze”. Its instinct for sense-making prefers almost any other answer. So it settles on some version of: “Hang on, you’ve been here before.” And you go, “I know it starts with an ‘f’…”
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