局部表象产生中行为性别差异的神经基础

Neural Basis of Behavioral Sex Difference during Local Image Generation

行为研究发现女性具有更好的局部表象产生能力,但其神经基础尚不清楚。研究采用事件相关电位技术以及小世界网络分析方法,探索局部表象产生中性别差异的大脑信息加工基础。结果显示在局部表象产生中,女性行为反应较男性更快,表象产生诱发的P300-650平均波幅更小,且大脑功能网络的平均路径长度更短。深入分析发现,反应时与脑网络的平均路径长度之间成正相关。该结果意味着低耗高效的大脑信息加工模式是女性具有更好的局部表象能力的神经基础。

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.