Local variation in brain temperature explains gender-specificity of working memory performance

Abstract

Exploring gender differences in cognitive abilities offers vital insights into human brain functioning. Our study utilized advanced techniques like magnetic resonance thermometry, standard working memory n-back tasks, and functional MRI to investigate if gender-based variations in brain temperature correlate with distinct neuronal responses and working memory capabilities. Interestingly, our findings revealed no gender disparity in working memory performance. However, we observed a significant decrease in average brain temperature in males during working memory tasks, a phenomenon not seen in females. Although changes in female brain temperature were not statistically significant, we found an inverse relationship between the absolute temperature change (ATC) and cognitive performance, alongside a correlation with blood oxygen level dependent (BOLD) neuronal responses. This suggests that in females, ATC is a crucial determinant for the link between cognitive performance and BOLD responses, a linkage not evident in males. Our results also suggest that females compensate for their brains heightened temperature sensitivity by activating additional neuronal networks to support working memory. This study not only underscores the complexity of gender differences in cognitive processing but also opens new avenues for understanding how temperature fluctuations influence brain functionality. SignificanceSex/gender differences in cognition are of high scientific and social interest. Yet, those differences (if any) remain elusive. Here we used magnetic resonance thermometry and functional MRI to examine, whether gender differences in working memory performance (WMP) are determined by subtle, yet detectable between-sex differences in local brain temperature fluctuations mediated by blood oxygen level-dependent (BOLD) neuronal responses. We found that WMP did not differ between genders. Yet, a females WMP was more sensitive to brain temperature variation compared to males. Furthermore, the negative impact of temperature on female cognitive functions was compensated by higher BOLD activity in other task-specific brain areas. This compensation may account for equivocal results of studies on the between-sex differences in cognitive performance.