Lethologica describes the annoying experience of having a word on the “tip of your tongue" that you are unable to fully grasp. When one is in a TOT state, certain features of the forgotten word are remembered, such as the first letter or where a syllable is stressed, along with an intense feeling that the word will return. People in this state report feelings of anguish, and some become obsessed with trying to remember the word at hand.
There are two explanations for why TOT happens: The direct access view states that TOT is triggered when a memory is not strong enough to remember the word, but just enough to evoke the experience. The inferential view argues that TOT is brought on when a person knows an element of the word, and attempts to piece together clues based on that knowledge. TOT is also more likely to occur when one is remembering something that is emotional. For example, trying to remember where a person met their partner would produce a higher rate of tip-of-the-tongue experiences than just asking for the name of a street.
TOT experiences are a universal phenomenon. In a study by B. L. Schwartz, 45 of 51 languages surveyed had a TOT idiom that referenced the tongue, mouth, or throat as a metaphor, including "on the tip/point/head of the tongue," "on the front of the tongue," “in the mouth and throat," and our personal favorite — “sparkling at the end of the tongue."
(via Psychonomic Bulletin & Review)
