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As observers we excel in decoding the emotional signals telling us that a social interaction is turning violent. The neural substrate and its modulation by personality traits remain ill understood. We performed an fMRI experiment in which participants watched videos displaying a violent conflict between two people. Observers' attention was directed to either the aggressor or the victim. Focusing on the aggressor (vs. focusing on the victim) activated the superior temporal sulcus (STS), extra-striate body area (EBA), occipital poles and centro-medial amygdala (CMA). Stronger instantaneous connectivity occurred between these and the EBA, insula, and the red nucleus. When focusing on the victim, basolateral amygdala (BLA) activation was related to trait empathy and showed increased connectivity with the insula and red nucleus. STS activation was associated with trait aggression and increased connectivity with the hypothalamus. The findings reveal that focusing on the aggressor of a violent conflict triggers more activation in categorical (EBA) and emotion (CMA, STS) areas. This is associated with increased instantaneous connectivity among emotion areas (CMA-insula) and between categorical and emotion (EBA-STS) areas. When the focus is on the victim, personality traits (aggression/empathy) modulate activity in emotion areas (respectively STS and postcentral gyrus/ BLA), along with connectivity in the emotional diencephalon (hypothalamus) and early visual areas (occipital pole). [ABSTRACT FROM AUTHOR]

In natural viewing conditions, different stimulus categories such as people, objects, and natural scenes carry relevant affective information that is usually processed simultaneously. But these different signals may not always have the same affective meaning. Using body-scene compound stimuli, we investigated how the brain processes fearful signals conveyed by either a body in the foreground or scenes in the background and the interaction between foreground body and background scene. The results showed that left and right extrastriate body areas (EBA) responded more to fearful than to neutral bodies. More interestingly, a threatening background scene compared to a neutral one showed increased activity in bilateral EBA and right-posterior parahippocampal place area (PPA) and decreased activity in right retrosplenial cortex (RSC) and left-anterior PPA. The emotional scene effect in EBA was only present when the foreground body was neutral and not when the body posture expressed fear (significant emotion-by-category interaction effect), consistent with behavioral ratings. The results provide evidence for emotional influence of the background scene on the processing of body expressions., (Copyright © 2012 Wiley Periodicals, Inc.)