Neural correlates of verbal memory encoding during semantic and structural processing tasks

Eighteen participants were imaged using fMRI to explore whether brain regions predicting successful verbal memory encoding during semantic decisions would continue to predict encoding during structural (non-semantic) decisions. Consistent with prior studies, left inferior frontal and fusiform regions were more active during semantic than structural decisions, and activity was greater for remembered than forgotten words during semantic decisions. Critically, structural decisions yielded significantly greater activity for remembered than forgotten words in these regions providing evidence that a common frontal-temporal network supports verbal memory encoding irrespective of orienting task. Further analysis revealed activity associated with successful encoding in the right precentral gyrus, suggesting other regions may also play a role in verbal encoding during non-semantic processing.