The TOT-object paradigm: Towards a greater understanding of speech disfluencies during tip-of-the-tongue states in older adults

Existing literature on speech disfluencies in healthy aging often categorizes them as indicators of word-finding difficulties, yet disfluencies can arise from multiple sources. To isolate those specifically linked to word-form retrieval failure, this study used the Tip-of-the-Tongue (TOT) Object Paradigm, a controlled task designed to elicit TOT states under well-defined conditions. Twenty-seven younger (<25 years) and twenty-six older (60–72 years) adults learned and named newly created objects associated with pseudoword labels. TOTs were categorized as solved or unsolved following phonological cueing. Participants produced more disfluencies during TOTs than during fluent naming, particularly silent pauses, filled pauses, conduites d’approche, and phonological errors, confirming that these behaviours index word-form retrieval difficulty. However, disfluency patterns were comparable in solved and unsolved TOTs, suggesting that they reflect retrieval difficulty rather than retrieval success. Older adults produced significantly more disfluencies than younger adults in the no-TOT condition, pointing to possible age-related differences in metacognitive monitoring, whereby older speakers may experience retrieval difficulty without consciously reporting a TOT. Overall, the TOT-object paradigm provides a reproducible method to investigate the behavioural and metacognitive correlates of word-form retrieval and their modulation by age.