Neurobiological Bases of Social Networks

Social network size, empathy, and white matter: A diffusion tensor imaging (DTI) study

Social networks are fundamental for social interactions, with the social brain hypothesis positing that the size of the neocortex evolved to meet social demands. However, the role of fractional anisotropy (FA) in white matter (WM) tracts relevant to mentalizing, empathy, and social networks remains unclear. In this study, we investigated the relationships between FA in brain regions associated with social cognition (superior longitudinal fasciculus (SLF), cingulum (CING), uncinate fasciculus, inferior fronto-occipital fasciculus), social network characteristics (diversity, size, complexity), and empathy (cognitive, affective). We employed diffusion tensor imaging, tract-based spatial statistics, and mediation analyses to examine these associations. Our findings revealed that increased social network size was positively correlated with FA in the left SLF. Further, our mediation analysis showed that lower FA in left CING was associated with increased social network size, mediated by cognitive empathy. In summary, our findings suggest that WM tracts involved in social cognition play distinct roles in social network size and empathy, potentially implicating affective brain regions. In conclusion, our findings offer new perspectives on the cognitive mechanisms involved in understanding others' mental states and experiencing empathy within supportive social networks, with potential implications for understanding individual differences in social behavior and mental health.

Validation of the Cognitive-Emotional Perspective Taking test in patients with neurodegeneration

BackgroundTheory of mind (ToM) is crucial for socioemotional interaction. ToM deficits may explain behavioral changes in dementia, especially Alzheimer's disease (AD) and frontotemporal dementia (FTD).ObjectiveThis study examined the psychometrics of a new ToM test in healthy adults, identified ToM differences in dementia syndromes, and assessed if ToM scores predict neuropsychiatric function and real-life behavior.MethodsThe UCSF Cognitive and Emotional Perspective Taking Test (CEPT) was evaluated in 195 healthy adults (age: 42.69 ± 16.20) and in a clinic cohort of 304 participants (age: 64.07 ± 9.2). Participants included healthy controls, AD, behavioral-variant frontotemporal dementia (bvFTD), semantic variant primary progressive aphasia (svPPA), non-fluent PPA (nfvPPA), and progressive supranuclear palsy (PSP) patients. CEPT's psychometrics were assessed, and ToM differences and predictions of neuropsychiatric symptoms were analyzed using regression models.ResultsIn controls, CEPT showed good validity and reliability. In patients, CEPT scores correlated with executive and emotional measures, but not language measures, showing good construct validity. Cognitive ToM was most impaired in AD and bvFTD, with less impairment in svPPA and PSP, and all patient groups showed impaired emotional ToM. ToM performance predicted real-life neuropsychiatric behavior, including anxiety, apathy, disinhibition, and aberrant motor behaviors.ConclusionsToM deficits appear early in dementia syndromes and predict neuropsychiatric behavior. Assessing ToM and social cognition with ecologically valid tasks may help identify altered social cognition in early neurodegeneration.

Neurotheology: Practical Applications with Regard to Integrative Psychiatry

PURPOSE OF REVIEW

Neurotheology is a nascent field of research and scholarship that seeks to understand the relationship between the brain and religious and spiritual phenomena. In the context of integrative psychiatry, neurotheology offers an intriguing intermediary between understanding how spirituality and religion affect brain function, and how this might be related to changes in mental health.

RECENT FINDINGS

A number of research studies over the years have observed that religious and spiritual beliefs, practices, and experiences can have a profound impact on a person's psyche. Many times, the effects are positive leading to lower depression, anxiety and distress. However, there are times that religion and spirituality can lead to negative beliefs and behaviors. Neurotheology seeks to understand both the positive and negative effects of religion and spirituality on mental health from a brain perspective. In addition, neurotheology offers important philosophical insights into the nature of the human mind and how we perceive the reality around us. This review evaluates these many topics as it considers how neurotheology can have practical applications with regard to integrative psychiatry.

Social network structure modulates neural activities underlying group norm processing: evidence from event-related potentials

Introduction

Social ties play a crucial role in determining the health and wellbeing of individuals. However, it remains unclear whether the capacity to process social information distinguishes well-connected individuals from their less-connected peers. This study explored how an individual's social network structure influences the dynamic processing of group norms, utilizing event-related potentials (ERPs).

Methods

The study involved 43 university students from the same class who participated in a social network study measuring metrics such as real-life social network size, in-degree, out-degree, and betweenness centrality. Subsequently, 27 students participated in an EEG study assessing their willingness to engage in various exercises after being exposed to peer feedback or in its absence.

Results

The results indicate that an individual's social network structure is significantly associated with the dynamic processing of group norms. Notably, well-connected individuals exhibited larger ERP amplitudes linked to feedback (e.g., N200, P300, and LPP), greater functional segregation within the brain network (e.g., local efficiency and clustering coefficient), and enhanced synchronization within frontal area and across different brain areas.

Discussion

These findings highlight that well-connected individuals possess enhanced sensitivity and efficiency in processing social information, pointing to potential areas for further research on the factors influencing social network evolution.

Increased functional connectivity between brain regions involved in social cognition, emotion and affective-value in psychedelic states induced by N,N-Dimethyltryptamine (DMT)

The modulation of social cognition is suggested as a possible mechanism contributing to the potential clinical efficacy of psychedelics in disorders involving socio-emotional and reward processing deficits. Resting-state functional Magnetic Resonance Imaging (rs-fMRI) can be used to detect changes in brain connectivity during psychedelic-induced states. Thus, this pharmacoimaging study investigates the effects of N,N-Dimethyltryptamine (DMT) on functional connectivity in brain areas relevant to social cognition, using a within-subject design in eleven healthy experienced users. The study included both an active and a control condition, conducted at different time points. The active condition involved DMT inhalation, while the control condition did not. Seed-based connectivity was measured for the two core regions involved in theory of mind and emotional processing, respectively, the posterior supramarginal gyrus and the amygdala. DMT increased supramarginal gyrus connectivity with the precuneus, posterior cingulate gyrus, amygdala, and orbitofrontal cortex. Additionally, increased connectivity emerged between the amygdala and orbitofrontal cortex. These results demonstrate that DMT modulates brain connectivity in socio-emotional and affective-value circuits, advancing our understanding of the neural mechanisms underlying the psychedelic experience and its potential therapeutic action.

Whole-brain gray matter maturation trajectories associated with autistic traits from adolescence to early adulthood

A growing number of evidence supports a continued distribution of autistic traits in the general population. However, brain maturation trajectories of autistic traits as well as the influence of sex on these trajectories remain largely unknown. We investigated the association of autistic traits in the general population, with longitudinal gray matter (GM) maturation trajectories during the critical period of adolescence. We assessed 709 community-based adolescents (54.7% women) at age 14 and 22. After testing the effect of sex, we used whole-brain voxel-based morphometry to measure longitudinal GM volumes changes associated with autistic traits measured by the Social Responsiveness Scale (SRS) total and sub-scores. In women, we observed that the SRS was associated with slower GM volume decrease globally and in the left parahippocampus and middle temporal gyrus. The social communication sub-score correlated with slower GM volume decrease in the left parahippocampal, superior temporal gyrus, and pallidum; and the social cognition sub-score correlated with slower GM volume decrease in the left middle temporal gyrus, the right ventromedial prefrontal and orbitofrontal cortex. No longitudinal association was found in men. Autistic traits in young women were found to be associated with specific brain trajectories in regions of the social brain and the reward circuit known to be involved in Autism Spectrum Disorder. These findings support both the hypothesis of an earlier GM maturation associated with autistic traits in adolescence and of protective mechanisms in women. They advocate for further studies on brain trajectories associated with autistic traits in women.

White and gray matter correlates of theory of mind in autism: a voxel-based morphometry study

Autism spectrum disorder (ASD) is characterized by difficulties in theory of mind (ToM) and social communication. Studying structural and functional correlates of ToM in the brain and how autistic and nonautistic groups differ in terms of these correlates can help with diagnosis and understanding the biological mechanisms of ASD. In this study, we investigated white matter volume (WMV) and gray matter volume (GMV) differences between matching autistic and nonautistic samples, and how these structural features relate to age and ToM skills, indexed by the Reading the Mind in the Eyes (RMIE) measure. The results showed widespread GMV and WMV differences between the two groups in regions crucial for social processes. The autistic group did not express the typically observed negative GMV and positive WMV correlations with age at the same level as the nonautistic group, pointing to abnormalities in developmental structural changes. In addition, we found differences between the two groups in how GMV relates to ToM, particularly in the left frontal regions, and how WMV relates to ToM, mostly in the cingulate and corpus callosum. Finally, GMV in the left insula, a region that is part of the salience network, was found to be crucial in distinguishing ToM performance between the two groups.

Social Media Use and Its Association with Mental Health and Internet Addiction among Portuguese Higher Education Students during COVID-19 Confinement

The use of social media was one of the most common way to keep in touch with friends and family during confinement. For higher education students, the fact that their universities were closed was a major change in their lives. The aim of this study is to relate the prevalence and type of social media with Internet addiction and mental health of university students in a district of Portugal during COVID-19 confinement. Mental health was studied by applying the reduced version of the Mental Health Inventory (MHI-5) and to measure the Internet use and dependence, the Internet Addiction Test (IAT) was used. The study (cross-sectional, descriptive, and correlational) used an online questionnaire, conducted on Google^® Forms and the link was sent to 4450 students, in the months of April to June 2020, during the confinement. A total of 329 valid questionnaires were obtained. We can conclude that regarding mental health, students in the 18-24 age group, single or divorced and who are not in a relationship, and with worse academic results, show worse levels of mental health. It is noteworthy that the students with the same characteristics also have the highest levels of addiction to internet.

Pair-bonding and social experience modulate new neurons survival in adult male and female prairie voles (Microtus ochrogaster)

Prairie voles are a socially monogamous species that, after cohabitation with mating, form enduring pair bonds. The plastic mechanisms involved in this social behavior are not well-understood. Neurogenesis in adult rodents is a plastic neural process induced in specific brain areas like the olfactory bulbs (OB) and dentate gyrus (DG) of the hippocampus. However, it is unknown how cell survival is modulated by social or sexual experience in prairie voles. This study aimed to evaluate if cohabitation with mating and/or social exposure to a vole of the opposite sex increased the survival of the new cells in the main and accessory OB and DG. To identify the new cells and evaluate their survival, voles were injected with the DNA synthesis marker 5-bromo-2'-deoxyuridine (BrdU) and were randomly distributed into one of the following groups: (A) Control (C), voles that did not receive any sexual stimulation and were placed alone during the behavioral test. (B) Social exposure (SE), voles were individually placed in a cage equally divided into two compartments by an acrylic screen with small holes. One male and one female were placed in opposite compartments. (C) Social cohabitation with mating (SCM), animals mated freely. Our findings demonstrated that SCM females had increases in the number of new cells (BrdU-positive cells) in the main olfactory bulb and new mature neurons (BrdU/NeuN-positive cells) in the glomerular layer (GlL). In contrast, these new cells decrease in males in the SE and SCM conditions. In the granular cell layer (GrL), SCM females had more new cells and neurons than the SE group. In the accessory olfactory bulb, in the anterior GlL, SCM decreased the number of new cells and neurons in females. On the other hand, in the DG, SCM and SE increase the number of new cells in the suprapyramidal blade in female voles. Males from SCM express more new cells and neurons in the infrapyramidal blade compared with SE group. Comparison between male and females showed that new cells/neurons survival was sex dependent. These results suggest that social interaction and sexual behavior modulate cell survival and influence the neuronal fate in a sex-dependent manner, in the OB and DG. This study will contribute to understand neural mechanisms of complex social and pair bond behaviors in the prairie voles; supporting adult neurogenesis as a plastic mechanism potentially involved in social monogamous strategy.

Detecting Suicide Ideation in the Era of Social Media: The Population Neuroscience Perspective

Social media platforms are increasingly used across many population groups not only to communicate and consume information, but also to express symptoms of psychological distress and suicidal thoughts. The detection of suicidal ideation (SI) can contribute to suicide prevention. Twitter data suggesting SI have been associated with negative emotions (e.g., shame, sadness) and a number of geographical and ecological variables (e.g., geographic location, environmental stress). Other important research contributions on SI come from studies in neuroscience. To date, very few research studies have been conducted that combine different disciplines (epidemiology, health geography, neurosciences, psychology, and social media big data science), to build innovative research directions on this topic. This article aims to offer a new interdisciplinary perspective, that is, a Population Neuroscience perspective on SI in order to highlight new ways in which multiple scientific fields interact to successfully investigate emotions and stress in social media to detect SI in the population. We argue that a Population Neuroscience perspective may help to better understand the mechanisms underpinning SI and to promote more effective strategies to prevent suicide timely and at scale.