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 of the target word, such as the first letter, its syllabic stress, and words similar in sound, meaning, or both sound and meaning. Individuals report a feeling of being seized by the state, feeling something like mild anguish while searching for the word, and a sense of relief when the word is found. While many aspects of the tip-of-the-tongue state remain unclear, there are two major competing explanations for its occurrence: the direct-access view and the inferential view. Emotion and the strength of the emotional ties to what is trying to be remembered can also have an impact on the TOT phenomenon. The stronger the emotional ties, the longer it takes to retrieve the item from memory.

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.Yu, Hui, Wang, Kai, Zhong, Ping, Cheng, Huai-Dong, Lv, Xin-Yi, Yuan, Li-Li. Investigations of memory monitoring in individuals with subjective cognitive decline and amnestic mild cognitive impairment. Cognitive and Behavioral Neurology. 2020;33(3):201-207. doi:10.1097/WNN.0000000000000242.Irak M, Soylu C, Turan G, et al. 2019. Neurobiological basis of feeling ofknowing in episodic memory. Cogn Neurodyn. 13:239–256.doi:10.1007/s11571-019-09520-5 This test aims to measure a test subject's accuracy of memory monitoring during the "memory extraction stage".Seelye AM, Schmitter-Edgecombe M, Flores J. 2010. Episodic memory predictions in persons with amnestic and nonamnestic mild cognitive impairment. J Clin Exp Neuropsychol. 32:433–441. doi:10.1080/13803390903201751

An occasional tip-of-the-tongue state is normal for people of all ages; however, it becomes more frequent as people age. TOT can be referred as an actual medical condition, but only when it becomes frequent enough to interfere with learning or daily life. This disorder is called anomic aphasia when acquired by brain damage, usually from a head injury, stroke, or dementia.

The tip of the tongue phenomenon has implications for research in psycholinguistics, memory, and metacognition.

History

The term "tip of the tongue" is borrowed from colloquial usage, and possibly a calque from the French phrase avoir le mot sur le bout de la langue ("having the word on the tip of the tongue"). The tip of the tongue phenomenon was first described as a psychological phenomenon in the text The Principles of Psychology by William James (1890), although he did not label it as such.James, W. (1890). Principles of Psychology. Retrieved from http://psychclassics.yorku.ca/James/Principles/

Sigmund Freud also discussed unconscious psychological factors, such as unconscious thoughts and impulses that might cause forgetting familiar words.Freud, S. (1965). The Psychopathology of Everyday Life. New York: Norton.

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. Brown and McNeill wanted to determine whether the feeling of imminent retrieval experienced in the tip of the tongue state was based on actual retrieval ability or was just an illusion.Baddeley, A, Eysenck, M., & Anderson, M. (2009). Memory. New York: Psychology Pres Inc.

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. Three types of positive TOT states were identified by Brown and McNeill: The participant recognized the word read by the experimenter as the word he had been seeking. The participant correctly recalled the word before it was read by the experimenter. The subject recalled the word they were seeking before the target word was read by the experimenter, but the recalled word was not the intended target. If a participant indicated a tip of the tongue state, they were asked to provide any information about the target word they could recall. Brown and McNeill found that participants could identify the first letter of the target word, the number of syllables of the target word, words of similar sound, words of similar meaning, syllabic pattern, and the serial position of some letters in the target word better than would be expected by chance. Their findings demonstrated the legitimacy of the feeling of knowing experienced in a tip of the tongue state. This study was the foundation for subsequent research about tip of the tongue phenomenon.

Universality

Tip of the tongue experiences occur in both men and women, and is known to occur in young adulthood, middle age, and older adulthood. TOT experiences in childhood have not been studied. Education level is not thought to be a factor in the experience of TOT states.Tim Brennen, Anne Vikan & Ragnhild Dybdahl (2007) Are tip-of-the-tongue states universal? Evidence from the speakers of an unwritten language, Memory, 15:2, 167-176, DOI: 10.1080/09658210601164743 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. In a study by B. L. Schwartz (1999), 45 of the 51 languages surveyed have an idiom referring to the tip of the tongue phenomenon that references the tongue, mouth, or throat as a metaphor. The direct English translations of these idioms are "on the tongue", "on the tip/point/head of the tongue", "on the top of the tongue", "on the front of the tongue", "sparkling at the end of the tongue", and "in the mouth and throat". Notably, the languages studied that did not have an equivalent idiom for the tip of the tongue were American Sign Language, Amharic, Icelandic, Kalenjin, and Kiswahili. However, tip of the finger experiences are reported by signers.

Causes

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.

Direct-access view

The direct-access view posits that the state occurs when memory strength is not enough to recall an item, but is strong enough to trigger the state. That is, the rememberer has direct access to the target word's presence in memory, even though it cannot be immediately recalled. Theories of the causes of tip of the tongue phenomenon that adopt direct-access views include the blocking hypothesis, the incomplete-activation hypothesis, and the transmission-deficit model.

Blocking hypothesis

The blocking hypothesis states that retrieval cues elicit the retrieval of a word related to the target that then blocks the retrieval of the correct word and causes the tip of the tongue phenomenon to occur. In other words, TOTs occur when plausible but incorrect responses to a query come to mind quickly. The person recognizes that the related words are incorrect but cannot retrieve the correct word because it is inhibited. These related words are termed blockers because they block the ability to retrieve the correct word. This accounts for why TOTs predict memory performance. Once the inhibition of the correct word is removed or the blockers are forgotten, the TOT will be resolved. Evidence for this hypothesis is minimal as it is difficult to measure. Most research that takes on this approach give participants blockers and see if they produce TOT states. This method is controversial as it is unclear if the blockers given produce TOT states or act as retrieval cues.

The hypothesis that blockers act more like retrieval cues is mainly supported by the idea of phonological similarities between the target word and the blocker word. Phonological blockers are words that sound similar to the target word. According to Bown & Harley, "phonological neighbors (of blockers) usually act as support in lexical retrieval rather than as a hindrance". Quote on page 164 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. This suggests that blockers have no effect on the retrieval or the causes of tip of the tongue states.

Incomplete-activation hypothesis

The incomplete activation hypothesis states that TOTs occur when the target word in memory is not sufficiently activated to be recalled but rememberers can sense its presence nonetheless. The accessibility of the target word fluctuates due to factors that increase its activation level, such as cues. The target word's activation level may fluctuate to a level that is high enough for it to be retrieved and the TOT state to be resolved.

Transmission-deficit model

The transmission deficit model is based on a multi-component theory of memory representation that suggests that semantic and phonological information is stored in memory and retrieved separately. The transmission deficit model posits that TOTs occur when there is activation of the semantic component of the target word memory but this activation does not pass on to the phonological level of the memory of the target word. Thus, TOTs are caused by the deficit in transmission of activation from the semantic memory store to the phonological memory store.

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.

Inferential view

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. This is to say that the rememberer infers their knowledge of the target word, and the imminence of retrieval depends upon the information that they are able to access about the target word from their memory. These views disregard the presence of the target word in memory as having an effect on creating tip of the tongue states.

Cue-familiarity theory