Bridging the self to the world: resting-state functional connectivity of the temporoparietal junction in post-traumatic stress disorder and its dissociative subtype

BACKGROUND: The temporoparietal junction (TPJ) is a cross-network hub involved in social cognition and attention, processes which are directly impacted by symptoms observed in clinical profiles of post-traumatic stress disorder (PTSD) and its dissociative subtype (PTSD + DS). METHODS: Using SPM12 and CONN, seed-based TPJ resting-state functional connectivity patterns were analyzed in individuals with PTSD (n = 81), PTSD + DS (n = 49), and healthy controls (n = 54) using four seeds [right anterior TPJ (raTPJ), left anterior TPJ (laTPJ), right posterior TPJ (rpTPJ), left posterior TPJ (lpTPJ)]. Post-hoc graph theoretical analyses were performed for raTPJ connectivity in PTSD + DS and healthy controls. RESULTS: As compared to healthy controls, PTSD + DS showed decreased raTPJ functional connectivity with critical anterior frontal lobe nodes involved in the ventral attention and social cognition networks (i.e., left ventrolateral and dorsomedial prefrontal cortices). PTSD showed decreased lpTPJ functional connectivity with the left superior parietal lobule as compared to healthy controls. When comparing PTSD to PTSD + DS, we observed increased bilateral TPJ functional connectivity with the cerebellum. Lastly, compared to healthy controls, both PTSD and PTSD + DS displayed decreased bilateral TPJ functional connectivity with the occipital lobe. Graph theoretical analyses revealed that PTSD + DS showed limited raTPJ involvement and instead more efficient neural communication between occipital lobe and frontal lobe structures as compared to healthy controls, suggesting a possible compensatory neural network in PTSD + DS. CONCLUSIONS: These findings reveal disruptions in TPJ neural circuitry in PTSD and PTSD + DS, which may carry cascading effects on intersecting neural networks involving the TPJ. Implications for psychotherapeutic treatments targeting disembodiment and social cognition are discussed.