Sex Differences in Aggressive Traits and Superior Temporal Cortical Responses to Monetary Loss

Background: Individuals vary in aggression traits. Here, we investigated how individual aggression is associated with altered reward and punishment processing in the brain and the neural bases of sex differences. Methods: Aggression was assessed by the Achenbach Adult Self-Report. We curated the Human Connectome Project dataset and modeled the BOLD signals to identify regional responses to reward and punishment blocks in the gambling task (n = 981, 473 men) as well as responses to the identification of negative emotional face in a target-matching task (n = 885, 436 men). Whole-brain statistical significance was assessed at the voxel-level p < 0.001 (uncorrected) with cluster-level family-wise error (FWE) correction at p < 0.05. For regional responses identified in men or women alone, we conducted slope tests to examine the sex differences in their relationships with individual aggression. Results: Whole-brain regression showed higher activation of the left superior temporal gyrus (STG) during gambling loss in men. We extracted the left STG response to reward versus baseline (STG-win β) and to loss versus baseline (STG-loss β), where β is the GLM contrast estimate. Left STG-loss β was significantly correlated with aggression score in men but not in women, and a slope test confirmed the sex difference (Z = 3.54, p < 0.001). STG-loss β but not STG-win β was significantly correlated with aggression score in men, and a slope test confirmed the specificity of this valence-related correlation (Z = 3.66, p < 0.001). Further, the correlations of STG-loss β and of STG response to negative emotional faces versus shapes with aggression score differed in men (Z = 2.70, p = 0.007). Conclusions: STG response to loss represents a neural correlate of aggression in men but not in women. The STG-loss response did not reflect a broader relationship between aggression and negative emotion.