Affective and non-affective neural alterations across generations in survivors and perpetrators in a post-genocide context

Armed conflicts are associated with profound and long-lasting mental health consequences, including post-traumatic stress disorder (PTSD), which has been linked to alterations in neural processing in both affective and non-affective domains. While numerous studies have documented such alterations shortly after traumatic events, far less is known about their long-term persistence, their intergenerational transmission, and potential differences between victims and perpetrators of mass violence. Addressing these gaps, the present pre-registered study examined neural and psychological correlates of trauma among civilian survivors and civilian former perpetrators of the 1994 Genocide against the Tutsis in Rwanda, as well as one of their offspring. Participants completed questionnaires assessing traumatic exposure and PTSD symptomatology, alongside four electrophysiological tasks targeting affective (threat processing, emotion recognition) and non-affective (sensory gating, auditory oddball) processes. Thirty years after the genocide, survivors exhibited higher PTSD symptom severity than former perpetrators, particularly for re-experiencing, hyperarousal, and avoidance. In affective tasks, survivors showed enhanced neural responses to threat and emotional stimuli, with some alterations persisting into the next generation. These effects were less pronounced or absent in former perpetrators and their offspring. In contrast, non-affective tasks revealed robust sensory and oddball effects but no consistent associations with PTSD in either group. Overall, the findings suggest that long-term neural alterations following genocide are more prominent in affective processing and are especially evident among survivors, the primary targets of the violence. The study further highlights selective intergenerational transmission of trauma-related symptomatology and demonstrates the feasibility of conducting electrophysiological research in post-conflict, non-Western contexts.