Quantitative analysis of lexical psycholinguistic properties in aphasia discourse production.

Purpose: This study aims to investigate lexical psycholinguistic properties (i.e. age of acquisition, concreteness, imageability, and familiarity) in English spoken discourse by persons with aphasia. It is hypothesised that persons with aphasia are more likely to use words with lower age of acquisition and higher concreteness, imageability and familiarity compared to the control group of neurologically intact adults, reflecting their lexical retrieval difficulties.

Method: Language samples of picture descriptions, story narratives, and procedural discourse were extracted from AphasiaBank. Words in the samples were cross-referenced with lexical items in large-scale psycholinguistic norms.

Result: Persons with aphasia tend to use words with lower age of acquisition in the story narrative task and higher familiarity in both the story narrative and procedural description task compared to the control group, demonstrating difficulties in retrieving later-acquired, and less familiar lexical items. Story narratives were particularly effective in distinguishing the two groups in terms of lexical psycholinguistic properties.

Conclusion: Distinctive patterns of lexical psycholinguistic properties were found in persons with aphasia discourse production compared with the control groups. These findings hold significant clinical implications for speech-language pathologists, as they underscore the value of integrating psycholinguistic measures into assessment protocols to enhance diagnosis accuracy and inform targeted therapeutic interventions.