Back to Woodworth: role of interlopers in the tip-of-the-tongue phenomenon. When a person reports that a word is on the tip of his or her tongue, that person often recalls instead another word that is similar in sound to the target word. Two opposite roles have been suggested for these interlopers. An older view (Woodworth, 1929) holds that they are instrumental in the development of tip-of-the-tongue (TOT) states because they obstruct successful retrieval of intended targets. A more recent view (R. Brown & McNeill, 1966) holds, on the other hand, that interlopers tend to nullify TOT states by facilitating complete retrieval of the intended targets. A study is reported in which participants were explicitly presented with interloper words. The results provide two planks of support for Woodworth's hypothesis. First, more TOT states occurred when the interloper was similar in sound to the target than when it was not. Second, more TOT states occurred when the interloper was presented at the actual time of retrieval than when it was presented earlier. It appears that interlopers tend to induce TOT states by obstructing retrieval, rather than to nullify them by facilitating retrieval.

The tip-of-the-tongue phenomenon: do experimenter-presented interlopers have any effect? When a person is in a tip-of-the-tongue (TOT) state, they will sometimes recall a word that is similar in sound to the word they are attempting to retrieve. Woodworth (1929) argued that these interloper words both cause and sustain TOT states, whereas Brown and McNeill (1966) suggested that they are part of the process that leads to TOT resolution. Jones and Langford (1987) and Jones (1989) explicitly presented interloper words along with definitions of words that subjects were asked to recall. They reported that interlopers that were phonologically related to the target word increased the incidence of TOTs and concluded that this supported Woodworth's position. In three experiments, we adopted the interloper paradigm, but also included a control group who heard the definitions without interloper words. In Experiment 1, the definitions that Jones used with phonological interlopers created more TOTs even when no interlopers were presented. In Experiments 2a and 2b, we matched definitions for the number of TOTs they produced in the absence of interlopers.

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 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 phenom 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". In contrast, an alternative argument suggests that phonological blockers hinder the abilit 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 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". 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. Anterior cingulate cortex (ACC) Posterior cingulate cortex (PCC) Right dorsolateral prefrontal cortex (DLPFC) Right inferior prefrontal cortex (RIPC) Bilateral anterior frontal cortex Posterior medial parietal cortex Bilateral lateral parietal cortex Bilateral superior prefrontal cortex Supramarginal gyrus Superior temporal gyrus Supplementary motor area Left insular cortex It was also shown 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 anterior cingulate cortex is also implicated in emotion and may show activation because of the emotional response to the tip of the tongue state. 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.

The tip-of-the-tongue (TOT) phenomenon is characterized by a temporary inability to retrieve a word despite a strong sense of familiarity. While extensive research has linked phonological processing to TOT, the exact nature of this relationship remains debated. The "blocking hypothesis" suggests that the retrieval of target words is interfered with by phonological neighbors, whereas the "transmission deficit hypothesis" posits that TOT arises from insufficient phonological activation of the target words. This study revisited this issue by examining the relationship between the microstructural integrity of the phonological processing brain network and TOT, utilizing graph-theoretical analyses of neuroimaging data from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), which included diffusion tensor imaging (DTI) data from 576 participants aged 18-87. The results revealed that global efficiency and mean degree centrality of the phonological processing network positively predicted TOT rates. At the nodal level, the nodal efficiency of the bilateral posterior superior temporal gyrus and the clustering coefficient of the left premotor cortex positively predicted TOT rates, while the degree centrality of the left dorsal superior temporal gyrus (dSTG) and the clustering coefficient of the left posterior supramarginal gyrus (pSMG) negatively predicted TOT rates. Overall, these findings suggest that individuals with a more enriched network of phonological representations tend to experience more TOTs, supporting the blocking hypothesis. Additionally, this study highlights the roles of the left dSTG and pSMG in facilitating word retrieval, potentially reducing the occurrence of TOTs. 18 7 2025 7 2025 15 7 493797 977 14 4 2025 29 6 2025 14 7 2025 18 07 2025 28 07 2025 30 07 2025 © 2025 by the authors. 2025 https://creativecommons.org/licenses/by/4.0/ Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( https://creativecommons.org/licenses/by/4.0/ ). The tip-of-the-tongue (TOT) phenomenon is characterized by a temporary inability to retrieve a word despite a strong sense of familiarity. While extensive research has linked phonological processing to TOT, the exact nature of this relationship remains debated. Additionally, this study highlights the roles of the left dSTG and pSMG in facilitating word retrieval, potentially reducing the occurrence of TOTs. tip-of-the-tongue phenomenon phonological processing DTI brain connectivity graph theory Social Science Foundation of Zhejiang Province, PR China 21YJRC09-1YB This study was funded by the Social Science Foundation of Zhejiang Province, PR China (21YJRC09-1YB). pmc-status-qastatus 0 pmc-status-live yes pmc-status-embargo no pmc-status-released yes pmc-prop-open-access yes pmc-prop-olf no pmc-prop-manuscript no pmc-prop-legally-suppressed no pmc-prop-has-pdf yes pmc-prop-has-supplement no pmc-prop-pdf-only no pmc-prop-suppress-copyright no pmc-prop-is-real-version no pmc-prop-is-scanned-article no pmc-prop-preprint no pmc-prop-in-epmc yes pmc-license-ref CC BY 1. Introduction The tip-of-the-tongue (TOT) phenomenon is a frustrating state in which speakers feel highly familiar with a word but are temporarily unable to retrieve it ( Brown & McNeil, 1966 ). TOT states occur in people’s daily lives. The blocking hypothesis of TOT proposes that dense phonological neighbors can obstruct the retrieval of intended targets, resulting in TOTs. Early researchers ( Wenzl, 1932 ; Woodworth, 1929 ) observed that in everyday life, when stuck in a TOT state, individuals often produced “interlopers” (or “blocking words”) that sound similar to the target word. Therefore, researchers hypothesized that the interlopers might interfere with the retrieval of the target words, resulting in TOTs. Any factors that increase the activation levels of these competitors can lead to retrieval failures, as is the case with TOTs. This hypothesis is further supported by recent bilingual studies, which reported that bilinguals experienced more TOTs than monolinguals, probably due to extra phonological interference from other language systems ( Stasenko & Gollan, 2019 ). Additionally, word retrieval has been shown to be slowed by phonological neighbors in a blocked cyclic naming task ( Breining et al., 2016 ; Qu et al., 2021 ). The transmission deficit hypothesis (TDH) offers an alternative explanation for TOTs, arguing that retrieval failure occurs not because of interference from interlopers, but due to insufficient phonological activation of target words caused by weakened connections between the semantic nodes and the phonological nodes or connections within the phonological nodes ( Mackay & Burke, 1990 ; Burke et al., 1991 ; James & Burke, 2000 ). In all models, age emerged as a significant predictor of TOT rates ( t s > 8.331, p s < 0.001), while gender did not show significant effects ( t s < −0.034, p s > 0.001). As the global metrics represent the richness of the lexical phonological network, these positive correlations indicate that a more enriched phonological lexical network can impede word retrieval and lead to an increased occurrence of TOTs. 3.2. Nodal Properties To investigate the node-specific contributions to the tip-of-the-tongue (TOT) rate, we conducted stepwise regression analyses separately for each nodal metric, with age, gender, and all ROIs as predictors. See Table 3 and Figure 1 for results. The bilateral pSTG is responsible for storing phonological representations ( Nozari, 2022 ), while the left PMA is involved in syllabification during speech production ( Indefrey & Levelt, 2004 ). Higher nodal metrics of these two regions indicate greater efficiency in facilitating the co-activation of a large number of phonological representations and/or syllabified segments. This can lead to increased interference with target words and