Similar patterns of cortical activity in females and males during item memory

Abstract

Anatomic and molecular sex differences exist in the brain, which suggests there may be functional differences. The present functional magnetic resonance imaging (fMRI) investigation aimed to identify the similarities and differences in brain activity between females and males during item memory. During encoding, abstract shapes were presented to the left or right of fixation. During retrieval, old and new shapes were presented at fixation and participants made "old-left", "old-right", or "new" judgments. Item memory was isolated by contrasting correct "old" responses to old items (with incorrect spatial memory responses; item memory hits) and "new" responses to old items (item memory misses). For both sexes, item memory produced activity in regions associated with visual long-term memory including the prefrontal cortex, parietal cortex, and visual processing regions. A sex by accuracy interaction analysis within each sub-region of activity produced largely null results, supporting common patterns of brain activity. However, there was sex-specific (male > female) activity within default network regions, which suggests males may have been less engaged in the task, and there was evidence for greater activity for females than males in language processing cortex. The present findings indicate that females and males employ similar patterns of brain activity during item memory.

Keywords: Item memory; Long-term memory; Recognition memory; Sex differences; fMRI.