Altered Cortico-Limbic Functional Connectivity During an Empathy Task in Subjects with Post-Traumatic Stress Disorder

Functional neuro-anatomy of social cognition in posttraumatic stress disorder: A systematic review

OBJECTIVE

Post-traumatic stress disorder (PTSD) is a common mental disorder following one or more traumatic events in which patients exhibit behavioural and emotional disturbances. Recent studies report alterations in social cognition with cerebral functioning modifications. While it is now established that brain function can be modified and severely altered following successive childhood traumas, less studies have focused on brain alterations in adults with normal social cognition development.

METHODS

We conducted a selective literature review by querying PubMed and Embase databases for titles of articles research on PTSD adults published from January 2000 to December 2021 focusing on adulthood traumatic events.

RESULTS

Majority of studies reported frontolimbic rupture, with limbic structures like amygdala missing top-down control of frontal regulation. These cerebral dysfunctions could be observed even without overt behavioural defects on social cognition tests.

CONCLUSION

These results can be analysed in light of intrinsic cerebral networks and we propose an attentional model of social threat information processing opening up perspective of social attentional rehabilitation in adjunction to usual care.

Functional Brain Connectivity During Narrative Processing Relates to Transportation and Story Influence

Engaging with narratives involves a complex array of cognitive and affective processes. These processes make stories persuasive in ways that standard arguments are not, though the underlying reasons for this remain unclear. Transportation theory proposes a potential explanation for this: narratives are processed in a way which makes individuals feel immersed in the world of a story, which in turn leads people to resonate emotionally with the events of the story. Recent fMRI studies have shown that the posterior medial cortex (PMC) and anterior insula (AI) play important roles in understanding the meaning of stories and experiencing the feelings they produce. In this study, we aimed to explore the AI’s and PMC’s role in narrative processing by measuring their functional connectivity with the rest of the brain during story listening, and how connectivity changes as a function of narrative transportation and the persuasiveness of the story. We analyzed data from 36 right-handed subjects who listened to two stories, obtained from podcasts, inside the fMRI scanner. After the scan, subjects were asked a series of questions, including a measure of how transported into the story they felt, how likely they would be to donate to causes related to the messages of the stories. We used searchlight multivariate pattern analysis (MVPA) to classify functional connectivity maps using seeds in both the AI and PMC and to compare these maps between participants who differed in transportation and prosocial intention. We found that connectivity to various regions successfully distinguished between high and low ratings on each of these behavioral measures with accuracies over 75%. However, only one pattern of connectivity was consistent across both stories: PMC-inferior frontal gyrus connectivity successfully distinguished high and low ratings of narrative transportation in both stories. All other findings were not consistent across stories. Instead, we found that patterns of connectivity may relate more to the specific content of the story rather than to a universal way in which narratives are processed.

Empathy and Coping in Allied Health Sciences: Gender Patterns

This study aimed to examine the patterns of associations between empathy and coping among undergraduate men and women studying at Allied Health Sciences. This cross-sectional study is part of a larger longitudinal study conducted in an Allied Health Sciences School. Participants were 183 undergraduate students from 12 training programs (e.g., Physiotherapy, Occupational Therapy, Speech Therapy). Their mean age was 20.79 years (SD = 2.64), and they were in their first, third, and fourth years of school. The instruments were the Brief-COPE and the Interpersonal Reactivity Index (IRI). Empathy correlated with coping strategies in both genders, though showing different patterns of association. First, distinct coping strategies were associated with the same empathy dimension (perspective taking) among women (positive reframing and self-blame) and among men (active coping). Second, the same three coping strategies appeared in both genders (seeking emotional or instrumental support and resorting to religion) but associated with different empathy dimensions (cognitive empathy among women and mostly emotional empathy among men). Third, among women (but not among men), two coping strategies (positive reframing and behavioral disengagement) were each simultaneously correlated with cognitive and emotional empathy in opposite directions. Fourth, emotional empathy correlated, only among women, with several coping strategies considered to be maladaptive (behavioral disengagement, denial and substance use). Among men, only one significant coping strategy was considered to be maladaptive (behavioral disengagement) and it was negatively correlated with cognitive empathy (perspective taking). Unlike in women, relationships between the empathic dimension of fantasy and coping strategies were non-significant among men. These distinct patterns of associations emerged despite significant differences in empathy by gender (fantasy, personal distress and empathic concern) and in coping strategies (instrumental support, emotional support, religion and venting). These results support the idea that the display of empathy might be associated with gender differences in the underlying empathy dimensions and in the coping strategies used to deal with stress in the undergraduate programs of Allied Health Sciences.

Increased functional segregation of brain network associated with symptomatology and sustained attention in chronic post-traumatic stress disorder

BACKGROUND

Traditional regional or voxel-based analyses only focus on specific brain regions or connectivity rather than the whole brain's functional organization. Using resting state functional magnetic resonance imaging (rs-fMRI), we aimed to explore the altered topological metrics, clinical symptoms and cognitive function in chronic post-traumatic stress disorder (PTSD) in order to identify the brain network mechanisms underlying these clinical and cognitive symptoms.

METHODS

Forty patients with unmedicated chronic PTSD and forty-two matched trauma-exposed healthy controls (TEHCs) underwent rs-fMRI, and the topological organization of the whole-brain network was calculated using graph theory. The Rapid Visual Information Processing (RVP) task and Wechsler Memory Scale-IV (WMS-IV) were used to evaluate the subjects' sustained attention and memory capacity. All clinical and cognitive measures and topological parameters of the PTSD patients and TEHCs were compared, and the relationships between altered network metrics and symptom severity were explored.

RESULTS

Compared with the TEHCs, the patients showed increases in the normalized clustering coefficient, small-worldness, normalized local efficiency and efficiency-based small-worldness. The left middle occipital gyrus showed increases in nodal global efficiency and nodal degree that were negatively correlated with the severity of PTSD symptoms. The altered connections in PTSD only involved the default mode network (DMN) and the occipital network.

LIMITATIONS

Comorbid conditions were included, and current cross-sectional study cannot conclude on causality.

CONCLUSIONS

Patients with chronic PTSD showed increased functional brain network segregation, mainly in the occipital cortex, which could be a protective or compensatory mechanism to alleviate clinical symptoms.

Relationship Between Theory of Mind, Emotion Recognition, and Social Synchrony in Adolescents With and Without Autism

Difficulty in social communication and interaction is a primary diagnostic feature of ASD. Research has found that adolescents with ASD display various impairments in social behavior such as theory of mind (ToM), emotion recognition, and social synchrony. However, not much is known about the relationships among these dimensions of social behavior. Adolescents with and without ASD participated in the study. ToM ability was measured by viewing social animations of geometric shapes, recognition of facial emotions was measured by viewing pictures of faces, and synchrony ability was measured with a spontaneously arising interpersonal movement task completed with a caregiver and an intentional interpersonal task. Attention and social responsiveness were measured using parent reports. We then examined the relationship between ToM, emotion recognition, clinical measures of attention and social responsiveness, and social synchronization that arises either spontaneously or intentionally. Results indicate that spontaneous synchrony was related to ToM and intentional synchrony was related to clinical measures of attention and social responsiveness. Facial emotion recognition was not related to either ToM or social synchrony. Our findings highlight the importance of biological motion perception and production and attention for more fully understanding the social behavior characteristic of ASD. The findings suggest that the processes underlying difficulties in spontaneous synchrony in ASD are different than the processes underlying difficulties in intentional synchronization.