Tip of the tongue

Lexical phenomenon
the psychological phenomenon

Tip of the tongue (also known as TOT, or lethologica) is the phenomenon of failing to retrieve a word or term from memory, combined with partial recall and the feeling that retrieval is imminent. The phenomenon's name comes from the saying, "It's on the tip of my tongue." The tip of the tongue phenomenon reveals that lexical access occurs in stages. People experiencing the tip of the tongue phenomenon can often recall one or more features of the target word, such as the first letter, its syllabic stress, and words similar in sound, meaning, or both sound and meaning. TOT states should be distinguished from FOK (feeling of knowing) states. FOK, in contrast, is the feeling that one will be able to recognize⁠—from a list of items⁠—an item that is currently inaccessible. There are still currently opposing hypotheses in the psychological literature regarding the separability of the process underlying these concepts. However, there is some evidence that TOTs and FOKs draw on different parts of the brain. TOTs are associated with the anterior cingulate, right dorsolateral prefrontal cortex, and right inferior cortex while FOKs are not. FOKs can be assessed through memory monitoring testing in which a test subject is asked to "estimate the likelihood" of recognizing when "prompted with a cue" or information that they previously failed to remember. This test aims to measure a test subject's accuracy of memory monitoring during the "memory extraction stage". The tip of the tongue phenomenon has implications for research in psycholinguistics, memory, and metacognition. Sigmund Freud also discussed unconscious psychological factors, such as unconscious thoughts and impulses that might cause forgetting familiar words. The first empirical research on this phenomenon was undertaken by Harvard researchers Roger Brown and David McNeill and published in 1966 in the Journal of Verbal Learning and Verbal Behavior. In their study, Brown and McNeill read out definitions (and only the definitions) of rare words to the study participants, and asked them to name the object or concept being defined. When the target word was later read by the experimenter participants were instructed to report whether they experienced a tip of the tongue state. Monolinguals, bilinguals, and multilinguals all experience tip of the tongue states, although with varying frequencies (see §⁠Effects of bilingualism below). Many languages other than English have equivalent colloquial terms for the tip of the tongue experience, suggesting that it is a common experience across cultures.

The causes of TOTs are largely unknown but numerous explanations have been offered. These explanations mainly fall within the realms of two overarching viewpoints: the direct access view and the inferential view. In contrast, an alternative argument suggests that phonological blockers hinder the ability to retrieve the target word causing a tip of the tongue state. There is more support for the idea that blockers act as neither primers nor enhancers, but rather more like a side effect. In Metcalf & Kornell's research the incubation period helped participants to retrieve the word by the same amount for the original non blocked TOTs and the blocked TOTs. According to cognitive psychologists Deborah M. Burke, of Pomona College, and Donald G. MacKay, of the University of California, Los Angeles, this phenomenon occurs due primarily to three reasons, all based on weakened neural connection: the lack of frequent use of a word, the lack of recent use of a word, and aging.

The inferential view of TOTs claims that TOTs aren't completely inaccessible, but arise from clues about the target that the rememberer can piece together. and event related functional magnetic resonance imaging (fMRI).

Several areas of the brain show increased activation in a TOT state. The following is a list of the specific structures that show increased activation during a tip of the tongue state:

Anterior cingulate cortex (ACC) that in TOT state the activation of the parahippocampal gyrus is decreased. Not much is known about the exact function of these areas in the tip of the tongue phenomenon. The areas activated during TOT may vary depending on the nature of the target word. For example, if the target word is a person's name, the fusiform face area will likely show activation as the rememberer processes the person's face. Problems like this make it difficult to determine what areas are specifically implicated in TOT states, and which are a byproduct of other cognitive functions. However, some inferences can be made about the roles of these structures based on theories of their functions derived from other studies of these structures, unrelated to TOT. It is hypothesized that the anterior cingulate cortex and the right dorsolateral prefrontal cortex operate as a circuit to detect conflict, and may perform this role in detecting the conflict between the feeling of knowing the target word and the recall failure. The posterior medial parietal cortex, bilateral lateral parietal cortex, and the bilateral superior prefrontal cortex are involved in retrieval and evaluation, and therefore may play a role in the metacognitive processes involved in the tip of the tongue phenomenon such as the evaluation of one's own knowledge and the probability of retrieval. Bilinguals seem to report the same amount of TOTs as monolinguals for proper names but significantly more TOTs for other words. In a task of picture naming, bilingual speakers were slower than monolinguals, even when they could use their first and dominant language. This could possibly be the result of bilinguals using the words less often than monolingual speakers. Bilinguals also represent virtually twice as many words and additional cognitive mechanisms for activation and inactivation of languages. Such mechanisms introduce added processing burden that monolinguals do not face. In addition, even when a task seems monolingual, bilingual system is never functionally "off." Research has been conducted to investigate the effects of lorazepam on TOT states in response to general knowledge question. In a recall task, participants who received lorazepam showed the same number of total recall answers to participants who had not received lorazepam. Research has been performed involving phonological priming and TOTs in which participants took either 200 mg of caffeine or a placebo. Compared with young adults, older adults generally report having more TOT states, fewer alternate words, and less phonological information about the target word. The underpinnings of TOT with regard to age have focused on neurological brain differences. Current research using neuroimaging compared the brain patterns of younger and older individuals experiencing TOT states. It appears that both older and younger individuals employ a similar network of brain regions during TOT states such as the prefrontal cortex, left insula, and sensorimotor cortex. However, older individuals show differences in activity in some areas compared to younger individuals. This may indicate a continued search when the retrieval process fails and a TOT state is experienced. Despite the association of increased age with lower levels of episodic memory and more frequent TOT states, the two phenomena seem to be largely independent of one another. Research has been conducted to find out how these particular diseases affect TOTs in these individuals. In a study by Beeson, Holland, and Murray (1997), participants with Alzheimer's disease and three classic aphasic syndromes (Broca's, anomic, and conduction aphasia) were instructed to name famous people. Those with anomic aphasia showed to be superior to the other groups in their ability to name famous people that were presented.

Research on priming and practice use single word tests to assess for the presence of TOT states. The first letter of the target word or a similar sounding word is given in order to prime for the target word. Evidence that comes from the usefulness of priming and practice in reducing TOT states is that most information in TOT states is low frequency; that is, it has not been used or recalled for some time. Support for priming has been found in that when individuals are given the first letter of the word they are trying to recall, they are more likely to overcome their TOT state. Incorrect words come to mind involuntarily that share similar phonological features with the target word.

The speed and accuracy with which speakers retrieve a word is influenced by the age in life at which that word was first learned. Specifically, early acquired words tend to be named more quickly and accurately than late acquired words (age of acquisition effect). It has been observed that the probability of experiencing a TOT state depends on the age at which the word is acquired in life: more TOT states are obtained with late acquired than with early acquired words.