Short-term memory and the integration of syntactic and semantic information in sentence processing: Evidence from a case of right-hemisphere language dominance

Purpose: We present the clinical case of AB, a right-handed individual who experienced a stroke affecting the right temporo-parietal cortex, resulting in phonological short-term memory (pSTM) impairment. Functional MRI revealed right-hemispheric language lateralization. We tested AB’s abilities to integrate syntactic and semantic information during sentence processing and how this is affected by pSTM deficits. Method: We administered an extensive battery of tasks to assess the integrity of AB’s pSTM and syntactic-semantic processing capacities, and compared his performance to a group of matched six controlsResult: AB showed difficulty comprehending syntactically complex sentences in a sentence-to-picture matching task and in a follow-up plausibility judgment task in which syntactic complexity, thematic role order, and sentence plausibility were manipulated. AB exhibited impairment in processing syntactically complex sentences with non-canonical patient-agent order, while performing relatively well on syntactically complex sentences with canonical agent-patient order. Sentence plausibility had no significant effect on comprehension accuracy. Conclusion: Our findings suggest that syntactic-semantic integration and phonological storage mechanisms can find support from right hemisphere structures and that syntactic and thematic complexity engage pSTM. The implications of these findings for clinical interventions targeting short-term memory are also discussed