Long-term affective and non-affective brain alterations across three generations following the genocide in Cambodia

The literature has largely indicated that trauma can lead to post-traumatic stress disorder (PTSD) and alterations in brain functioning. However, to what extent these alterations remain present decades after the traumatic event, and how the next generations may also suffer from them, remains unclear, especially in a non-Western culture. Uniquely, the present project focused on survivors of the Cambodian genocide and the subsequent two generations to determine whether brain alterations are observable approximately five decades after the traumatic event and in subsequent generations from the same society. Using portable electroencephalography (EEG), we used four experimental tasks—two targeting non-affective processing (i.e., sensory gating, oddball) and two targeting affective processing (i.e., emotion recognition, threat processing). Results indicated that although the rate of PTSD symptoms was similar across generations, the affective reaction to threat for the LPP and FMθ was primarily observed or intensified in the directly affected generation (i.e., G0), regardless of the presence of PTSD. We also observed that G0 exhibited reduced attenuation over standard tones in the oddball task for the N100 and a reduced sensory gating effect on the auditory P200. The present study underscores that affective and non-affective alterations might still be present decades after a trauma, but are not necessarily observable in subsequent generations. Our results also support a dissociation between reported PTSD symptoms and neural alterations.