Linked Sex Differences in Cognition and Functional Connectivity in Youth

TLDR

Sex differences in cognition are well documented, yet their neural origins remain largely unknown. The study examined whether sex differences in cognitive profiles are linked to patterns of resting‑state functional connectivity in 674 youths aged 9–22. Resting‑state fMRI revealed that males had higher between‑module connectivity while females had higher within‑module connectivity, and support‑vector‑machine classifiers predicted sex from connectivity with 71 % accuracy. Behaviorally, males outperformed females on motor and spatial tasks, whereas females were faster on emotion identification and nonverbal reasoning, and the degree of a participant’s cognitive “male” or “female” profile correlated with the masculinity or femininity of their connectivity pattern.

Abstract

Sex differences in human cognition are marked, but little is known regarding their neural origins. Here, in a sample of 674 human participants ages 9–22, we demonstrate that sex differences in cognitive profiles are related to multivariate patterns of resting-state functional connectivity MRI (rsfc-MRI). Males outperformed females on motor and spatial cognitive tasks; females were faster in tasks of emotion identification and nonverbal reasoning. Sex differences were also prominent in the rsfc-MRI data at multiple scales of analysis, with males displaying more between-module connectivity, while females demonstrated more within-module connectivity. Multivariate pattern analysis using support vector machines classified subject sex on the basis of their cognitive profile with 63% accuracy (P < 0.001), but was more accurate using functional connectivity data (71% accuracy; P < 0.001). Moreover, the degree to which a given participant's cognitive profile was "male" or "female" was significantly related to the masculinity or femininity of their pattern of brain connectivity (P = 2.3 × 10−7). This relationship was present even when considering males and female separately. Taken together, these results demonstrate for the first time that sex differences in patterns of cognition are in part represented on a neural level through divergent patterns of brain connectivity.