Neural Basis of Behavioral Sex Difference during Local Image Generation

Previous behavioral studies reported that females performed faster than males in generating the local details of image. However, the neural basis of behavioral sex difference during local image generation is not clear. Generally, reaction time is considered as an index of speed of brain information processing. And the small-world topology of functional brain connectivity could provide high global and local efficiency of parallel information processing. Therefore, it was speculated that stronger small-world effect underlay females’ faster reaction time during local image generation. Total 28 people (14 males and 14 females) participated in the experiment and they were informed to observe a set of experimental pictures and then generate corresponding mental image to the global or local cue. The reaction time and event-related potential were recorded. The behavioral and electrophysiological data obtained in the experiment were analyzed by ANOVA and small-world measures, respectively. Results showed that females had the shorter reaction time, the smaller P300-650 amplitude and the shorter average path length of brain network in local image generation. Additionally, there was a positive correlation between the reaction time and the average path length. The present findings suggested that the lower cost and higher efficiency of brain information processing supported the better behavioral performance.