Valence, gender, and lateralization of functional brain anatomy in emotion: a meta-analysis of findings from neuroimaging.

We performed quantitative meta-analyses on 65 neuroimaging studies of emotion. In an earlier report (NeuroImage 16 (2002), 331). we examined the effects of induction method, specific emotions, and cognitive demand in emotional tasks. This paper focuses on the effects of emotional valence (positive vs negative and approach vs withdrawal) and gender on regional brain activations, with particular emphasis on hypotheses concerning lateralization of brain function in emotion. Overall, we found no support for the hypothesis of overall right-lateralization of emotional function, and limited support for valence-specific lateralization of emotional activity in frontal cortex. In addition, we found that males showed more lateralization of emotional activity, and females showed more brainstem activation in affective paradigms. The study provides evidence that lateralization of emotional activity is more complex and region-specific than predicted by previous theories of emotion and the brain.