Personality traits predict brain activation and connectivity when witnessing a violent conflict

Abstract

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).

Endogenous testosterone is associated with lower amygdala reactivity to angry faces and reduced aggressive behavior in healthy young women

“…We did find associations however between bilateral STG reactivity to angry faces and aggression on a between-participant basis. STG activity has previously been shown to increase when focusing one’s attention on the aggressor relative to the victim of a violent conflict66, and when appraising unfair proposals as negative67. These findings, in addition to its general involvement in mentalizing62 and threat detection50, suggest that persons with higher reactivity to anger in STG might be more likely to interpret the opponent’s intentions as hostile and hence respond aggressively.…”

Amygdala atrophy affects emotion-related activity in face-responsive regions in frontotemporal degeneration

“…It has been reported that FTD patients with the largest atrophy in this network, exhibit the most prominent lack of attention for social cues . Furthermore, activation of the BLA during perception of social emotional expressions is modulated by trait empathy (Van den Stock, Hortensius, et al, 2015), a key deficit in bvFTD.…”

“…In particular, it is hypothesized that amygdalar responses to facial emotion perception influence activation in face-responsive regions like the pSTS and FFA. In addition, there is evidence that the M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 4 modulatory influence on occipito-temporal areas originates primarily in the basolateral section of the amygdala (Bickart, Hollenbeck, Barrett, & Dickerson, 2012;Van den Stock, Hortensius, Sinke, Goebel, & de Gelder, 2015).…”

Affective and cooperative social interactions modulate effective connectivity within and between the mirror and mentalizing systems

“…We predicted that a common engagement of the mirror and mentalizing systems alongside pSTS underpins the processing of both interaction types (Centelles et al, ; Georgescu et al, ; Iacoboni et al, ; Van den Stock et al, ), while increasing levels of cooperativity and affectivity should reflect in heightened activity of, respectively, mirror and mentalizing areas processing shared behavioral intentions versus shared mental states (Canessa et al, ). We expected such a functional distinction to emerge from effective connectivity within a strongly interconnected network with pSTS as driving input, in which increasing cooperativity and affectivity promote, respectively, the visuomotor processing of motor intentions and the attribution of mental states by key‐nodes of the mirror (vPMC and SPL) and mentalizing (vmPFC) systems.…”