Sex differences in the brain during long-term memory

Abstract

Sex differences exist in both brain anatomy and neurochemistry (Cahill, 2006). Many differences have been identified in brain regions associated with long-term memory including the dorsolateral prefrontal cortex, hippocampus, and visual processing regions (Andreano & Cahill, 2009). There is, however, a paucity of research investigating whether and how these differences translate into differences in functional activity. Part 1 investigated sex differences in the patterns of functional activity in the brain during spatial long-term memory, item memory, memory confidence, and false memory. In addition, a meta-analysis was conducted to identify whether there were consistent sex differences in the brain across different long-term memory types. Part 2 determined whether there were sex differences in the patterns of functional connectivity in the brain during spatial long-term memory. Specifically, differences in functional connectivity between the hippocampus and the rest of the brain in addition to the thalamus and the rest of the brain were investigated. Finally, Part 3 investigated whether the observed differences in the patterns of activity (identified in Chapter 1) had sufficient information to classify the sex of individual participants. The results of Part 3 argue against the popular notion that the average female brain and average male brain are not significantly different (Joel et al., 2015). More broadly, the studies presented in this dissertation argue against the widespread practice of collapsing across sex in cognitive neuroscience.