The cognitive connectome of men and women: a study on sex differences across three cohorts

Cognitive processes are essential for efficient daily functioning. Demographic factors such as age and education influence cognitive performance. However, the impact of sex on cognition is less understood and previous research has reported inconsistent findings. We investigated sex differences in cognitively unimpaired adults in three cohorts, using two complimentary approaches: a univariate approach to compare direct performance across cognitive domains and the multivariate approach of graph theory to compare global and nodal features as well as the modular organization of cognitive connectomes. We included 4,259 cognitively unimpaired participants (334 from the GENIC cohort, 3,703 from the National Alzheimer’s Coordinating Center [NACC], and 222 from the Alzheimer’s Disease Neuroimaging Initiative [ADNI]). Cognitive variables were corrected for age and education, and cognitive connectomes were constructed using Spearman correlation coefficients. Sex differences in cognitive performance were examined through ANCOVAs as well as global and nodal network measures. Univariate analyses showed significant sex differences in three out of five cognitive domains across cohorts, mainly of small effect sizes. Graph theory analyses revealed minimal sex differences in cognitive module organization and no significant differences on global network measures, except for a higher modularity observed in women compared to men in the NACC. In contrast, nodal analyses revealed sex differences in several network measures. Sex differences in cognition seem to be of small effect size and limited to specific cognitive domains or cognitive variables, while the overall organization and global features of cognitive connectomes were largely comparable between men and women. Future studies should clarify whether men and women may rely on slightly different cognitive strategies to approach cognitive tasks without overt differences in cognitive ability. This study explored whether men and women differ in their cognitive abilities. Previous research has suggested that women may perform slightly better on verbal tasks, while men may do better on some attention or visuospatial tasks. However, several studies have only reported small or no differences, and it remains unclear whether cognitive performance does differ between men and women or they basically use different strategies to perform cognitive tasks. To investigate this question, the researchers analyzed data from three international populations of cognitively healthy adults. Participants completed a range of cognitive tests. The research team used two types of analysis: traditional analyses that compare performances on each individual cognitive task, and a newer method called graph theory, which looks at how different cognitive skills are connected and work together as a network, known as the “cognitive connectome.” The results confirmed that, although men and women differed slightly on some specific cognitive tasks, these differences were generally small. Most importantly, the overall organization of the cognitive connectome was highly comparable in men and women. However, when the researchers looked more closely at individual parts of the connectome, they found some subtle differences. These differences suggest that men and women may rely on slightly different cognitive strategies when performing certain tasks, even though they reach a similar overall level of performance. These findings support the idea that men and women are more similar than different in their cognitive abilities.