Sex differences in the functional lateralization of emotion and decision making in the human brain

Abstract

Dating back to the case of Phineas Gage, decades of neuropsychological research have shown that the ventromedial prefrontal cortex (vmPFC) is crucial to both real-world social functioning and abstract decision making in the laboratory (see, e.g., Stuss et al., ; Bechara et al., 1994; Damasio et al., ). Previous research has shown that the relationship between the laterality of individuals' vmPFC lesions and neuropsychological performance is moderated by their sex, whereby there are more severe social, emotional, and decision-making impairments in men with right-side vmPFC lesions and in women with left-side vmPFC lesions (Tranel et al., 2005; Sutterer et al., 2015). We conducted a selective review of studies examining the effect of vmPFC lesions on emotion and decision making and found further evidence of sex-related differences in the lateralization of function not only in the vmPFC but also in other neurological structures associated with decision making and emotion. This Mini-Review suggests that both sex and laterality effects warrant more careful consideration in the scientific literature. © 2016 Wiley Periodicals, Inc.

Keywords: amygdala; cognitive function; emotion; functional lateralization; sex differences; vmPFC.

Figure 1

The Iowa Gambling Task. vmPFC = ventromedial prefrontal cortex. Patients with lesions in the vmPFC typically show a preference for cards from the disadvantageous deck throughout the task, leading to a net loss. Neurologically healthy participants typically learn to avoid the disadvantageous decks over the course of the task, eventually drawing exclusively from the advantageous cards for a net gain.

Figure 2

Combined lesion overlap of male and female patients in Tranel et al. (2005). The colors represent the number of overlapping lesions at each voxel. Men with right-sided lesions and women with left-sided lesions displayed moderate to severe impairments in social conduct, emotion, and decision-making. Women with right-sided lesions and men with left-sided lesions showed mild or no impairments in all three domains.

Figure 3

Summary of sex-related differences in effects of unilateral lesions (Gaznick et al., 2014; Sutterer et al., 2015; Tranel et al., 2005).