RESUMO
Background: Discourse analyses yield quantitative measures of functional communication in aphasia. However, they are historically underutilized in clinical settings. Confrontation naming assessments are used widely clinically and have been used to estimate discourse-level production. Such work shows that naming accuracy explains moderately high proportions of variance in measures of discourse, but proportions of variance remain unexplained. We propose that the inclusion of circumlocution productions into predictive models will account for a significant amount more of the variance. Circumlocution productions at the naming-level, while they may not contain the target word, are similar to the content that contributes to discourse informativeness and efficiency. Thus, additionally measuring circumlocution may improve our ability to estimate discourse performance and functional communication. Aim: This study aimed to test whether, after controlling for naming accuracy, the addition of a measure of circumlocution into predictive models of discourse-level informativeness and efficiency would account for a significant amount more of the variance in these discourse-level outcomes. Methods & Procedures: Naming and discourse data from 43 people with poststroke aphasia were analyzed. Naming data were collected using 120 pictured items and discourse data were collected using two picture description prompts. Data scoring and coding yielded measures of naming accuracy, incorrect response type, communicative informativeness, and efficiency. We used robust hierarchical regression to evaluate study predictions. Outcomes & Results: After controlling for naming accuracy, the inclusion of circumlocution into predictive models accounted for a significant amount more of the variance in both informativeness and efficiency. The subsequent inclusion of other response types, such as real word and nonword errors, did not account for a significant amount more of the variance in either outcome. Conclusions: In addition to naming accuracy, the production of circumlocution during naming assessments may correspond with measures of informativeness and efficiency at the discourse-level. Reducing the burden of estimating patients' functional communication will increase our ability to estimate functional communication using tools that are easy to administer and interpret.
RESUMO
Despite the many mistakes we make while speaking, people can effectively communicate because we monitor our speech errors. However, the cognitive abilities and brain structures that support speech error monitoring are unclear. There may be different abilities and brain regions that support monitoring phonological speech errors versus monitoring semantic speech errors. We investigated speech, language, and cognitive control abilities that relate to detecting phonological and semantic speech errors in 41 individuals with aphasia who underwent detailed cognitive testing. Then, we used support vector regression lesion symptom mapping to identify brain regions supporting detection of phonological versus semantic errors in a group of 76 individuals with aphasia. The results revealed that motor speech deficits as well as lesions to the ventral motor cortex were related to reduced detection of phonological errors relative to semantic errors. Detection of semantic errors selectively related to auditory word comprehension deficits. Across all error types, poor cognitive control related to reduced detection. We conclude that monitoring of phonological and semantic errors relies on distinct cognitive abilities and brain regions. Furthermore, we identified cognitive control as a shared cognitive basis for monitoring all types of speech errors. These findings refine and expand our understanding of the neurocognitive basis of speech error monitoring.
