Response strategies in aphasic sentence comprehension: An analysis of two cases

Abstract

Background: A consistent pattern of responding in a test of sentence comprehension has been interpreted both as a direct reflection of the aphasic patient's ability to understand specific sentence types, and as an indirect indication of the operation of systematic response strategies. Less attention has been directed at the questions of how residual comprehension abilities and response strategies might jointly influence response patterns, and of the potential modifiability of such strategies through intervention.Aims: This study illustrates how patients' response patterns reflect a complex interaction between residual syntactic knowledge and different response strategies. These strategies may change in response to simple task manipulations and in response to therapeutic feedback.Methods & Procedures: We report sentence comprehension data from two aphasic patients who produced dissimilar comprehension patterns for semantically reversible sentences tested in three experiments: sentence–picture verification (yes/no), sentence–picture matching (forced choice), and in response to systematic feedback (intervention).Outcomes & Results: Both patients' performance was shown to reflect response strategies with distinct potential for modification by changes in task demands and by therapeutic intervention. The strategies adopted appeared to reflect differences in retained knowledge about structural cues to sentence meaning; paradoxically, the more superficial strategy—reflecting no initial appreciation of sentence structure—was the more amenable to modification.Conclusions: Results highlight the importance of assessing comprehension with a number of different tasks, and of recognising patients' tendencies to rely on response strategies, when interpreting aphasic sentence comprehension. The clinical utility of identifying such response biases and comprehension strategies as a basis for intervention is discussed.