Date of Degree


Document Type


Degree Name



Speech-Language-Hearing Sciences


Loraine K. Obler

Committee Members

Elizabeth Galletta

Mira Goral

Subject Categories

Psycholinguistics and Neurolinguistics


tip-of-the-tongue, lexical retrieval, aging, psycholinguistics


One of the notable language difficulties experienced by healthy older adults is word retrieval failure, specifically the tip-of-the-tongue state (TOT). A TOT occurs when one has a strong sense of knowing the word, such that the semantic content is accessed, but the entirety of the word’s phonology is temporarily inaccessible. Such retrieval difficulty is attributable, at least in part, to characteristics of the target word. Psycholinguistic features may uniquely influence the semantic and/or phonological stages of word production. An additional factor known to influence TOT-likelihood is noun type: proper nouns elicit TOTs more often than do common nouns. The discrepancy between the likelihood of a TOT for the two noun types is hypothesized to be due to their differential representation in the mental lexicon. The difference hinges on the connection architecture at the semantic level (between semantic nodes and the lemma node) for common and proper nouns – the former characterized by convergent, many-to-one connections and the latter by one-to-one connections. The extent to which the representation of common and proper nouns accounts for retrieval difficulties as a consequence of psycholinguistic factors known to interact with the semantic level and phonological levels is poorly understood. Therefore, this dissertation examined the contribution of several psycholinguistic features to the likelihood of successful retrieval at the semantic and phonological stages in a set of common and proper nouns.

Fifty-two monolingual English-speaking, healthy older adults between the ages of 54 and 89 participated in a TOT-inducing, computerized word naming task. Participants named targets from a selected subset of the total stimulus set of 1,102 words (587 proper nouns and 515 common nouns). Each target was cued independently from a picture and definition; however, cue type was counterbalanced across participants such that no-one saw the same target in both cue modalities. Analyses focused on the influence of the psycholinguistic features (namely self-rated frequency and familiarity, Zipf frequency, MRC familiarity, word-length in phonemes, neighborhood density, and first-syllable frequency) on word-retrieval performance at both stages of retrieval using a two-step model of TOTs.

The results of the current research offer novel evidence for the independent influence of frequency and familiarity on the likelihood of retrieval success at the semantic and phonological levels of lexical processing. Specifically, frequency was found to benefit both stages of retrieval for proper names and the phonological stage alone for common nouns. This finding suggests a frequency-related advantage such that one-to-one connections are favored at the semantic and phonological levels. By contrast, familiarity benefited retrieval at both stages for both noun types, indicating that an effect of familiarity is agnostic to connection architecture at each level. The present study also offers new evidence for a cue-related retrieval advantage at the semantic level for common nouns (but not proper nouns) retrieved from picture cues. There was no effect of the other psycholinguistic features tested for either word type or stage of lexical processing. This research establishes the independent contribution of psycholinguistic features to TOT occurrence in common and proper nouns in relation to the overall architecture of the semantic and phonological systems.