Poster D80, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Investigating semantic and episodic representations for concepts
Wei-Chun Wang1, Simon W Davis1, Roberto Cabeza1; 1Duke University
Functional neuroimaging studies suggest that similar regions are activated during both semantic memory and episodic memory retrieval. The current study sought to extend these findings by investigating semantic memory and episodic memory representations of object concepts as measured by functional MRI. To this end, we scanned participants as they covertly named a series of object pictures. Following this incidental encoding task, they were then presented with a series of object names and instructed to covertly recall the object pictures that they previously saw. Using representational similarity analysis, we identified regions exhibiting greater encoding-retrieval similarity (ERS) to object information irrespective of retrieval success (i.e., semantic memory) and regions exhibiting greater ERS to memory success (i.e., episodic memory). Posterior cingulate/retrosplenial cortex and left parahippocampal cortex showed ERS between the initial object picture and subsequent object name presentations for both remembered and forgotten individual objects, suggesting that semantic memory representations are stored in these regions. On the other hand, left inferior frontal and fusiform gyri showed ERS between the initial object picture and subsequent object name presentations for hits but not misses, suggesting that episodic memory representations are stored in these regions. Additionally, left parahippocampal cortex and inferior frontal gyrus were more functionally connected for hits than misses, suggesting an interaction between these regions.
Topic Area: LONG-TERM MEMORY: Episodic