Preliminary evidence for two patterns of phonological similarity judgments of word-pairs by persons with Aphasia

Abstract

ABSTRACT Background Phonological similarity judgments of word-pairs have been shown to reflect the structure of a phonological network of word-forms, where words are connected to each other if they differ by one phoneme. Word-pairs that are closer together in the phonological network are more likely to be rated as sounding similar than word-pairs that are farther apart in the network. This behavioral pattern indicates sensitivity to the underlying structure of the phonological network. Aims This study is an extended replication of previous research that seeks to identify if persons with aphasia (PWA), who often have phonological processing impairments, are sensitive to the large-scale structure of the phonological network. Methods and Procedures Seven PWA completed the phonological similarity judgment task. They heard two words aurally and made a binary indication if the words “sound similar”. Words in each pair differed in phonological similarity, as defined by the distance between the words in the phonological network, with values from 1 to 5. We analyzed the proportion of similar responses for word-pairs at each phonological network distance. Post-hoc analyses of individual-level performance and comparison to control samples (10 younger adults and 10 older adults) were conducted after examining the primary research question results. Outcomes and Results There were two patterns of performance. Four PWA performed similarly in ratings across all phonological network distances as younger and older adult control participants, and in concordance with previous research. There was a negative, nonlinear trend in the proportion of similar judgments as distance increased. Three PWA, however, had a different pattern of performance, such that word-pairs with distances of 3, 4, and 5 had higher proportions of similar judgments compared to the other samples of participants. Conclusion The two patterns of performance may point to clinically useful information, after further research, about phonological representations and processing in aphasia that may inform precision rehabilitation.