Posttraumatic stress disorder and the social brain: Affect‐related disruption of the default and mirror networks

Neuroimaging studies of mentalizing (i.e., theory of mind) consistently implicate the default mode network (DMN). Nevertheless, the social cognitive functions of individual DMN regions remain unclear, perhaps due to limited spatiotemporal resolution in neuroimaging. Here we use electrocorticography (ECoG) to directly record neuronal population activity while 16 human participants judge the psychological traits of themselves and others. Self- and other-mentalizing recruit near-identical cortical sites in a common spatiotemporal sequence. Activations begin in the visual cortex, followed by temporoparietal DMN regions, then finally in medial prefrontal regions. Moreover, regions with later activations exhibit stronger functional specificity for mentalizing, stronger associations with behavioral responses, and stronger self/other differentiation. Specifically, other-mentalizing evokes slower and longer activations than self-mentalizing across successive DMN regions, implying lengthier processing at higher levels of representation. Our results suggest a common neurocognitive pathway for self- and other-mentalizing that follows a complex spatiotemporal gradient of functional specialization across DMN and beyond.

Background: Poor social connection is a central feature of posttraumatic stress disorder (PTSD), but little is known about the neurocognitive processes associated with social difficulties in this population. We examined recruitment of the default network and behavioral responses during social working memory (SWM; i.e., maintaining and manipulating social information on a moment-to-moment basis) in relation to PTSD and social connection. Methods: Participants with PTSD (n = 31) and a trauma-exposed control group (n = 21) underwent functional magnetic resonance imaging while completing a task in which they reasoned about two or four people's relationships in working memory (social condition) and alphabetized two or four people's names in working memory (nonsocial condition). Participants also completed measures of social connection (e.g., loneliness, social network size).Results: Compared to trauma-exposed controls, individuals with PTSD reported smaller social networks (p = .032) and greater loneliness (p = .038). Individuals with PTSD showed a selective deficit in SWM accuracy (p = .029) and hyperactivation in the default network, particularly in the dorsomedial subsystem, on trials with four relationships to consider. Moreover, default network hyperactivation in the PTSD group (vs. trauma-exposed group) differentially related to social network size and loneliness (p's < .05). Participants with PTSD also showed less resting state functional connectivity within the dorsomedial subsystem than controls (p = .002), suggesting differences in the functional integrity of a subsystem key to SWM.Conclusions: SWM abnormalities in the default network may be a basic mechanism underlying poorer social connection in PTSD.

Mentalizing describes the human ability to comprehend one’s own and others’ mental states and is seen as one of the core competencies of psychotherapists. Current research has emphasized the importance of both early dyadic attachment as well as broader sociocultural environmental input on the development of mentalizing. This study investigates whether mentalizing skills, operationalized via reflective functioning (RF), might be influenced by training and working conditions. This study was a matched case-control comparison, cross-sectional study. RF was assessed in a total of 10 psychotherapy trainees working in private practice at the beginning (group A; n = 5) and end (group B; n = 5) of their psychotherapy training (training association: Gestalt Therapy, Institute of Integrative Gestalttherapy Vienna) and in a total of 40 health professionals (institution: General Hospital Vienna—Social Medical Center South, Vienna, Department of Psychiatry, acute psychiatric ward) at the beginning of (group C; n = 20) and without (group D; n = 20) mentalization based therapy training. The participants differed from each other regarding their training, but participants of the same institution were matched. RF scores were significantly higher in group A and B than in group C and D (A,C: p = 0.0065, Odds Ratio (OR): 0.0294; A,D: p = 0.0019, OR: 0.0132; B,C: p = 0.0065, OR: 0.0294, B,D: p = 0.0019, OR: 0.0132). RF scores were not significantly different among groups A and group B (A,B: p > 0.9999) or between groups C and D (C,D: p = 0.6050). The current study suggests that mentalizing skills might be rather slow to improve by training, but that they might be influenced by the context.