Investigation on whether co-verbal gesture use can facilitate lexical retrieval in connected speech in normal speakers and speakers with aphasia

Abstract

The present study investigated whether co-verbal gesture use can facilitate lexical retrieval in connected speech in normal speakers and speakers with aphasia. Narrative samples of 58 normal speakers and 58 speakers with fluent aphasia were extracted from the Cantonese AphasiaBank. Based on the indicators of word-finding difficulty in connected speech adapted from previous research, and a gesture annotation system with independent coding of gesture forms and functions, all instances of word-finding difficulties were identified in all speech samples. Each instance of word-finding difficulty was associated with occurrence of any gestures, and, if there were, whether and in what form of gestures it was resolved. The present study found that co-verbal gesture use did not affect success rate of resolving word-finding difficulties. The Lexical Retrieval Hypothesis about the facilitative functions of iconic and metaphoric gestures in lexical retrieval was not confirmed in the current study. Among speakers with aphasia, the naming ability at single-word level and the overall language ability were found to be the two strongest indicators of success rate of resolving word-finding difficulties. Challenges in conducting research related to word-finding difficulties, and the clinical implications in gesture-based language intervention for speakers with aphasia are discussed.