"It's one of those, you know...those...um. Those things, uh--you know what I'm talking about, right?"
Sometimes the simplest words sit right there on the tip of your tongue, tantalizing you with how close--but not close enough--they feel to your consciousness. You can reach out to grab them, and either come away with that mini "Eureka!" moment of stumbling upon the word you were looking for--"Chaise lounge, that's it!"--or that maddening, why-can't-I-remember-this-basic-noun mixture of frustration and embarrassment. Ever wondered why that happens? The explanation seems obvious enough: We cram a lot of information into our heads. Who can blame the brain for blanking, every once in awhile?
But why can we often remember what the word sounds like, remember the "feel" of it, but stumble around for the correct arrangement of letters? io9 picked up on a recent study that offers one explanation of why words on the tips of our tongues can stay maddeningly out of reach. It's hardly the first study to take a look at the issue, but if offers a solid explanation--and it has a great title.
"Sparkling at the end of the tongue: The etiology of tip-of-the-tongue phenomenology" starts by laying out some previous research into the TOT experience, which it says is a universal phenomenon. A chunk of the paper even delves into why we use the tongue to explain our brains grasping for the right words--and that metaphor is definitely universal, as they found 45 out of 51 languages use a similar saying to explain the phenomenon.
The study presents several longstanding theories about TOTs, but calls one of the oldest into question. That theory focuses on the tip-of-tongue phenomenon as a "temporary breakdown in lexical retrieval," which essentially describes a mental breakdown in understanding and relating the "phonological, semantic, and lexical components" of a word.
Here's an interesting alternative theory presented by the paper: Mental blocking.
"The blocking hypothesis states that TOTs occur because rememberers retrieve target words related to the correct target but are recognized by the rememberers as being incorrect. According to the blocking hypothesis, TOTs occur because the rememberers recognize blockers as incorrect but cannot retrieve the correct but inhibited target. A. S. Brown wrote, 'the blocking perspective suggests that the TOT represents a memory search that has become sidetracked.' The incorrect intruders that sidetrack retrieval have been labeled as blockers, interlopers, and related words. The hypothesis suggests that variables that increase the retrieval of these blockers will both inhibit correct recall and promote TOTs. Like other direct-access models, the blocking hypothesis easily accounts for why TOTs accurately predict memory performance. Accuracy is ensured because TOTs are caused by activation of target memories. Because TOTs are caused by activation of the sought-for word, a change in retrieval conditions may remove the processes that are inhibiting retrieval. Retrieval may be inhibited by blockers, but the blockers are recognized as incorrect. Once the inhibition is removed by a change in retrieval cues or the forgetting of the blocker, TOTs will be resolved."
This is just one possible explanation, and the study offers several others that are worth checking out. It concludes that "Current data suggest a complexity of the nature of the TOT experience and the interaction between phenomenology and object-level cognition in general." Despite the tip-of-tongue phenomenon being utterly universal, we still don't know enough to say exactly why it happens.