Brain and behavioral evidence for altered social learning mechanisms among women with assault-related posttraumatic stress disorder

Abstract

Current neurocircuitry models of PTSD focus on the neural mechanisms that mediate hypervigilance for threat and fear inhibition/extinction learning. Less focus has been directed towards explaining social deficits and heightened risk of revictimization observed among individuals with PTSD related to physical or sexual assault. The purpose of the present study was to foster more comprehensive theoretical models of PTSD by testing the hypothesis that assault-related PTSD is associated with behavioral impairments in a social trust and reciprocity task and corresponding alterations in the neural encoding of social learning mechanisms. Adult women with assault-related PTSD (n=25) and control women (n=15) completed a multi-trial trust game outside of the MRI scanner. A subset of these participants (15 with PTSD and 14 controls) also completed a social and non-social reinforcement learning task during 3T fMRI. Brain regions that encoded the computationally modeled parameters of value expectation, prediction error, and volatility (i.e., uncertainty) were defined and compared between groups. The PTSD group demonstrated slower learning rates during the trust game and social prediction errors had a lesser impact on subsequent investment decisions. PTSD was also associated with greater encoding of negative expected social outcomes in perigenual anterior cingulate cortex and bilateral middle frontal gyri, and greater encoding of social prediction errors in the left temporoparietal junction. These data suggest mechanisms of PTSD-related deficits in social functioning and heightened risk for re-victimization in assault victims; however, comorbidity in the PTSD group and the lack of a trauma-exposed control group temper conclusions about PTSD specifically.

Reduced local segregation of single‐subject gray matter networks in adult PTSD

“…Middle frontal gyrus is crucial for executive control, working memory and emotion processing that are disrupted in PTSD (Morey et al, 2009). A previous task-based fMRI study also showed that PTSD patients demonstrated disrupted responses to trauma stimuli in bilateral middle frontal cortex (Hou et al, 2007), and it has been speculated that heightened encoding of negative expected social value in middle frontal gyrus might contribute to hypervigilance and attentional biases for threat in PTSD patients (Cisler et al, 2015).…”

Trauma exposure and PTSD symptoms associate with violence in inner city civilians

“…Our data accompany several others that have found effects for trauma and PTSD on social function. For instance, women with PTSD have altered social learning that may predispose them to re-victimization (Cisler et al, 2015). Trauma survivors with PTSD exhibit lower empathic resonance (Nietlisbach, Maercker, Rossler, & Haker, 2010), and have deficits in mentalizing and emotion recognition (Plana, Lavoie, Battaglia, & Achim, 2014).…”

Diminished positive affect and traumatic stress: A biobehavioral review and commentary on trauma affective neuroscience

“…The authors also examined this same sample in a related paradigm that attempted to address the social deficit symptomatology observed to be characteristic of PTSD ( Cisler et al, 2015 ). Specifically, the authors utilized a behavioral Trust Game completed outside the scanner in which participants invested a chosen amount of money into another “player” on each trial (which was, unbeknownst to them, actually a computer), and could receive back a portion of the tripled investment dictated by the other player on each trial.…”

“…Initial efforts in PTSD to utilize theory-driven computational models to infer latent parameters of information processing involved in reward-based decision making have already surfaced ( Myers et al, 2013 ), including the integration of these models with imaging data to bridge behavioral and brain-based units of analysis ( Cisler et al, 2015 ; Ross et al, 2018 ). Such an approach holds tremendous value for advancing the field of biological psychiatry more generally ( Montague et al, 2012 ; Wang and Krystal, 2014 ) but also for PTSD and trauma affective neuroscience research more specifically for several reasons.…”