Brain processing of visual sexual stimuli in human males

TLDR

The neural processing of visual sexual stimuli in humans remains poorly defined despite its sociobiological importance. The study aims to propose a model of the brain processes underlying human male sexual arousal. Using PET and Statistical Parametric Mapping, the authors measured regional cerebral blood flow in nine healthy males exposed to graded visual sexual stimuli and identified brain regions correlated with sexual arousal markers. The claustrum showed the strongest activation, with additional increases in paralimbic, striatal, and posterior hypothalamic regions, while several temporal areas exhibited decreased blood flow.

Abstract

Despite its critical sociobiological importance, the brain processing of visual sexual stimuli has not been characterized precisely in human beings. We used Positron Emission Tomography (PET) to investigate responses of regional cerebral blood flow (rCBF) in nine healthy males presented with visual sexual stimuli of graded intensity. Statistical Parametric Mapping was used to locate brain regions whose activation was associated with the presentation of the sexual stimuli and was correlated with markers of sexual arousal. The claustrum, a region whose function had been unclear, displayed one of the highest activations. Additionally, activations were recorded in paralimbic areas (anterior cingulate gyrus, orbito-frontal cortex), in the striatum (head of caudate nucleus, putamen), and in the posterior hypothalamus. By contrast, decreased rCBF was observed in several temporal areas. Based on these results, we propose a model of the brain processes mediating the cognitive, emotional, motivational, and autonomic components of human male sexual arousal.