Evaluating the Contribution of Executive Functions to Language Tasks in Cognitively Demanding Contexts.

Purpose: The purpose of this study was to determine the degree to which the executive functions of attention switching and inhibition predicted performance on language subtests from the Temple Assessment of Language and (Verbal) Short-Term Memory in Aphasia (TALSA; N. Martin, Minkina, Kohen, &Kalinyak-Fliszar, 2018) across 3 interval conditions (no delay, 5-s delay, and 5-s filled delay), which was designed to add a memory and executive load to language tasks. Method: This study was a post hoc experimental design. Participants included 27 people with aphasia who were administered 5 subtests from the TALSA (Naming, Word Repetition, Nonword Repetition, Category Judgment, and Rhyming Judgment), which were selected to evaluate input and output levels of processing in the 3 interval conditions listed above. Three executive tasks were administered to evaluate inhibition (Simon and Flanker tasks) and attention switching (number-letter shifting). Results: Independent variables were proportion correct on each TALSA task in 3 separate time conditions, and predictor variables were efficiency on the Simon task and number-letter shifting task. Linear regression modeling was completed, which revealed that inhibition was a significant predictor of proportion correct for Word Repetition and Category Judgment in the 5-s filled interval condition. Conclusions: Our findings indicate that inhibition plays a role in completing tasks that require lexical and/or semantic processing in cognitively demanding conditions. Attention switching was not a significant predictor for any task. These results are an important step toward creating methods to evaluate executive skills in the context of language production.