Torture Exposure Modulates Cognitive Control and Attention Neural Network Connectivity During a Go/Nogo Task.

Abstract

Background: Torture trauma is characterised by intentional uncontrollable acts, but the long-term effects of torture exposure on cognitive control brain mechanisms are unknown.

Methods: A final sample of 33 torture survivors (TS) and 44 non-torture survivors (NTS), all with a refugee background, completed a Go/NoGo response inhibition task during fMRI scanning. Data-driven independent components analysis identified active networks across the task, and within Go, NoGo and error of commission trials. Groups were compared on within/between network connectivity, controlling for demographic and psychological symptom covariates. Secondary analyses investigated whether network connectivity moderated the associations between torture exposure and severity on fear (e.g. re-experiencing) and dysphoria (e.g. anhedonia) posttraumatic stress disorder (PTSD) symptoms.

Results: The TS group exhibited decreased connectivity (compared to NTS controls) within the posterior default mode network (specifically the left precuneus) and auditory-motor network (specifically right superior temporal gyrus STG), and reduced connectivity between the dorsomedial frontal network (dmFN) and dorsal attention network (dAN) across the Go/NoGo task. The TS group also showed comparatively more negative ventral attention network connectivity during NoGo (i.e. inhibition) trials. No behavioral effects were observed. Secondary analyses revealed that association between torture exposure and elevated PTSD dysphoria (not fear) symptoms was moderated by reduced connectivity in the right STG and between the dmFN-dAN.

Conclusions: Response inhibition, attention and motor networks appear less connected in torture survivors, which may be specifically linked to PTSD dysphoria symptom profiles. Findings suggest that targeting cognitive control processes may hold promise for alleviating post-traumatic symptoms amongst survivors of torture.