Abstract
Background. Neuroimaging studies have revealed that regions in the superior temporal sulcus (STS) show activity during biological motion perception (Grossman et al., 2000), detection of face identity or gaze direction (Hoffman and Haxby, 2000), and also during understanding concepts of social action (Martin and Weisberg, 2003). We aim to determine whether or not the human STS has a common area for all of these tasks. Method. Subjects participated in multiple localizer tasks designed to activate the human posterior STS. These tasks included 1) point-light biological motion versus motion-matched scrambled controls (e.g. Grossman and Blake, 2001), 2) social vignettes depicting geometric shapes engaged in social or mechanical actions (i.e. Martin and Weisberg, 2003), and 3) stationary faces versus pixel-scrambled faces. Using a GLM analysis, we first identified the posterior STS from each localizer for the individual subjects. We then conducted a whole brain conjunction analysis across all three tasks to determine the common regions that were common to all of them. Results. The conjunction analysis revealed bilateral regions common to all localizers in the STS, EBA/hMT+ (Extrastriate Body Area, and Medial Temporal area) and in the dorsolateral prefrontal cortex (DLPFC). Conjunction analysis for only the face and biological motion tasks revealed additional areas in the fusiform gyrus (e.g. fusiform face and body areas). Larger areas of DLPFC and unilateral areas near the sylvian fissure (Left Hemisphere) were found with the conjunction of ROIs between the biological motion and social mechanical tasks. The conjunction between face and social mechanical ROIs revealed additional areas in the fusiform gyrus. Conclusions. This study suggests that a common network of brain areas, including a specific portion of the posterior STS, is involved in processing socially relevant information across these three different tasks.