Sex Differences In Spatial Location Memory During Navigation

Spatial memory is an essential ability for living.Although the sex differences in spatial memory consistently emerge,the results are diverse,ranging from “significant differences' ' to ‘‘no differences' '.So far,there is no hypothesis that can give a reasonable explanation for these results.In this study,we sought to determine the underlying sex differences observed during spatial working memory,by examining neurofunctional differences in the distinct cortical regions that lay within the spatial memory network and its behavioral relevance to navigation.To do this,we used functional magnetic resonance imaging(f MRI)to measure neural responses whilst healthy young adults were engaged in spatial memory task with different memory loads.Our results illustrate consistent spatial memory networks between female and male groups,but also provide evidence for sex-specific networks whereby males utilize more frontal structures than females,and females activate a distributed network inclusive of more parietal regions.In addition,sex divergences in spatial memory appear when task difficulty increases.To further explore the sex-linked association between spatial memory and navigation,we correlated neural representations in the bilateral middle frontal gyrus(MFG),superior frontal gyrus(SFG),inferior parietal lobule(IPL)and superior parietal lobule(SPL)with their self-reported navigation ability.Behavioral results show that males were better at navigation than females.Importantly,we found that greater activity within the left inferior parietal lobe(l IPL)during the encoding phase possessed better navigational ability in the male group and the female group did not find this correlation.Overall,our study provides novel empirical evidence demonstrating sex differences in spatial memory during navigation,and demonstrate the role of task-difficulty expressed in terms of spatial memory involvement.