Belinda Liddell, Jessica Cheung, Miriam Den, Pritha Das, Tim Outhred, Kim Felmingham, Gin Malhi, Angela Nickerson, Mirjana Askovic, Jorge Aroche, Mariano Coello and Richard Bryant Torture is characterized by being severe,... [ view full abstract ]
Belinda Liddell, Jessica Cheung, Miriam Den, Pritha Das, Tim Outhred, Kim Felmingham, Gin Malhi, Angela Nickerson, Mirjana Askovic, Jorge Aroche, Mariano Coello and Richard Bryant
Torture is characterized by being severe, uncontrollable and interpersonal, and may have specific and long-term effects on brain function. Other groups who have experienced traumas that share these qualities (e.g. domestic violence, childhood maltreatment) have modelled distinct changes in neural responses to trauma reminders or fear-based cues, including overall reduced fear responsivity, reflected in over-activation of medial prefrontal regions. Furthermore, neuroimaging studies of PTSD tend to focus on associations between brain activity and clinical symptoms, without accounting for the effect of current stress – an important consideration for resettled refugees. In this series of functional magnetic resonance imaging (fMRI) studies, we examined the neural correlates of fear processing disruptions in a sample of 80 trauma-exposed refugees, 30 who are survivors of torture. In two tasks, participants viewed fear face stimuli or, or were instructed to engage in emotional regulation (i.e. cognitive reappraisal) strategies vs naturally viewing threat-related images. The findings indicate that PTSD symptoms, torture experiences and current levels of settlement stress had different effects on fear processing pathways: torture exposure was associated with heightened engagement of prefrontal regions during fear face and negative scene processing, mirroring patterns of emotion over-modulation, whereas current stress was correlated with arousal centre of the brain. Torture survivors also demonstrated reduced cognitive reappraisal success, supported by both behavioural data and increased activation of amygdala, ventral striatum and insula. The findings indicate that torture exposure may have a significant and long-term effect on fear processing mechanisms in the brain. Clinical implications and
