Heart and ____ or give and ____? An exploration of variables that influence binomial completion for individuals with and without aphasia

Purpose: The goal of this research was to institute an evidence base behind commonly used elicitation materials known as binomials (e.g., “day and night”) that are commonly used for persons with aphasia (PWAs). The study explored a number of linguistic variables that could influence successful binomial completion in nonaphasic adults and PWAs. Method: Thirty nonaphasic adults and 11 PWAs were asked to verbally complete 128 binomials; responses were scored by accuracy and reaction time. Binomials were coded according to the following independent variables: frequency of usage, phonological (e.g., alliteration, rhyme) and semantic (i.e., antonymy) relationships, grammatical category of the response, and number of plausible binomial completions. Results: Regression analyses demonstrated that, for both groups, greater accuracy was predicted by presence of antonymy and absence of a phonological relationship. Though reaction time models differed between groups, items that elicited a greater number of response options led to longer latencies across participants. Conclusion: Findings suggest that clinicians consider antonymy as well as the number of plausible responses for a given prompt when adapting the level of difficulty for their clients. Results also contribute to broader interdisciplinary research on how automatic language is processed in adults with and without neurogenic communication disorder.