Neural bases of semantic-memory deficits for events

This study investigated the neural bases of event-related semantic-memory deficits among people with aphasia due to left-hemisphere (LH) stroke. A novel task using naturalistic photographic stimuli and patient-friendly procedures was used to test event-related semantic knowledge. In the task, participants decided whether depicted events were normal (represented in semantic memory) or were abnormal (not represented in semantic memory). Performance on this Event task was correlated with deficits in actionand object-concept processing and on standardized language measures, especially actionand verb-processing deficits. Logistic regression analyses examined lesion correlates of patient performance on the Event task. Surprisingly, increasing LH lesion size in action ROIs was associated with improved performance on the event-knowledge task. These findings suggest that action processing may play a special role in event-related semantic memory representations. Furthermore, they are consistent with recent claims that the right hemisphere may be especially important for activation of event-related knowledge.