The expression and persistence of vivid and distressing intrusive memories, is a central feature of Post-Traumatic Stress Disorder (PTSD). It remains largely unknown why these traumatic memories persist in some individuals, and fade away in others. Current understanding of PTSD links this persistence to the disruption of memory functions involved in the formation and updating of the memory trace. During this talk, I will present an alternative (and complementary) hypothesis, rooted in the idea that the variation across individuals in the response to trauma may additionally depend on the disruption of the brain system that normally allows the control over memory, a central mechanism of active forgetting (Mary et al., 2020). This presentation will be articulated around the findings of a longitudinal neuroimaging study realized in a cohort of 120 individuals exposed to the 11/13 Paris terrorist attacks. This research program is centered on the Think/No-Think task developed to study the suppression of neutral and inoffensive intrusive memories paired with a reminder cue. I will then illustrate how the computational modelling of predictive processing associated with such intrusive memories may help to unravel the alterations of control mechanisms in PTSD that would otherwise remain hidden (Leone et al., 2022), and further discuss how such mechanisms may influence the persistence of the trauma and resilience processes.

Dr. Pierre Gagnepain (PhD, HDR)Research Associate at INSERM (CR1)

Pierre Gagnepain – Computational model of intrusion control to understand PTSD