Iconic Sound-Shape Correspondences in Aphasia

Purpose: To examine speech iconicity for shape in aphasia, we compared shape iconicity ratings from people with aphasia to those from neurologically intact individuals and evaluated how these ratings relate to phonological and semantic processing profiles in aphasia. Method: Twelve people with aphasia and twelve age- and gender-matched neurologically intact participants rated how rounded or pointed 50 auditory pseudowords sounded, using a 5 point scale. Ratings from participants with aphasia were compared to predicted shape iconicity ratings derived from reference ratings from prior work and to ratings from neurologically intact participants. For participants with aphasia, correlations between individual ratings and predicted ratings were related to measures of phonological and semantic processing. Results: Ratings from people with aphasia were significantly correlated with both the predicted ratings and the ratings from neurologically intact participants. Relative to ratings from neurologically intact people, ratings from people with aphasia had weaker correlations to predicted ratings. There were indications that greater language impairment was associated with greater disruption of iconicity ratings; in particular, deficits in phonological segmentation and semantic processing were associated with reduced sensitivity to shape iconicity. Conclusion: These findings suggest that sensitivity to shape iconicity is preserved to varying degrees in individuals with aphasia. Disruption of phonological and semantic processing appears to affect shape iconicity processing in aphasia.