Sex commonalities and differences in the relationship between resilient personality and the intrinsic connectivity of the salience and default mode networks

Sex differences in the relationship between brain gray matter volume and psychological resilience in late adolescence

Psychological resilience reflects an individual's ability to adapt and cope successfully in adverse environments and situations, making it a crucial trait in resisting stress-linked mental disorders and physical diseases. Although prior literature has consistently shown that males are more resilient than females, the sex-linked neuroanatomical correlates of psychological resilience are largely unknown. This study aims to explore the sex-specific relation between psychological resilience and brain gray matter volume (GMV) in adolescents via structural magnetic resonance imaging (s-MRI). A cohort of 231 healthy adolescents (121/110 females/males), aged 16 to 20 completed brain s-MRI scanning and Connor-Davidson Resilience Scale (CD-RISC) and other controlling behavioral tests. With s-MRI data, an optimized voxel-based morphometry method was used to estimate regional GMV, and a whole-brain condition-by-covariate interaction analysis was performed to identify the brain regions showing sex effects on the relation between psychological resilience and GMV. Male adolescents scored significantly higher than females on the CD-RISC. The association of psychological resilience with GMV differed between the two sex groups in the left ventrolateral prefrontal cortex extending to the adjacent anterior insula, with a positive correlation among males and a negative correlation among females. The sex-specific association between psychological resilience and GMV might be linked to sex differences in the hypothalamic-pituitary-adrenal axis and brain maturation during adolescence. This study may be novel in revealing the sex-linked neuroanatomical basis of psychological resilience, highlighting the need for a more thorough investigation of the role of sex in future studies of psychological resilience and stress-related illness.

Sex differences in development of functional connections in the face processing network

BACKGROUND AND PURPOSE

Understanding sex differences in typical development of the face processing network is important for elucidating disruptions during atypical development in sex-linked developmental disorders like autism spectrum disorder. Based on prior sex difference studies in other cognitive domains, this study examined whether females show increased integration of core and extended face regions with age for face viewing, while males would show increased segregation.

METHODS

This study used a cross-sectional design with typically developing children and adults (n = 133) and a functional MRI face localizer task. Psychophysiological interaction (PPI) analysis examined functional connectivity between canonical and extended face processing network regions with age, with greater segregation indexed by decreased core-extended region connectivity with age and greater integration indexed by increased core-extended region connectivity with age.

RESULTS

PPI analysis confirmed increased segregation for males-right fusiform face area (FFA) coupling to right inferior frontal gyrus (IFG) opercular when viewing faces and left amygdala when viewing objects decreased with age. Females showed increased integration with age (increased coupling of the right FFA to right IFG opercular region and right occipital face area [OFA] to right IFG orbital when viewing faces and objects, respectively) and increased segregation (decreased coupling with age of the right OFA with IFG opercular region when viewing faces).

CONCLUSIONS

Development of core and extended face processing network connectivity follows sexually dimorphic paths. These differential changes mostly occur across childhood and adolescence, with males experiencing segregation and females both segregation and integration changes in connectivity.

Neural correlates of perceived and relative resilience in male and female patients with irritable bowel syndrome

BACKGROUND

Patients with irritable bowel syndrome (IBS) show lower resilience than healthy controls (HCs), associated with greater symptom severity and worse quality of life. However, little is known about affected markers of resilience or the influence of sex. Furthermore, as resilience is complex, a comprehensive assessment, with multiple resilience measures, is needed. Therefore, we aimed to evaluate perceived and relative resilience and their neural correlates in men and women with IBS.

METHODS

In 402 individuals (232 IBS [73.3% women] and 170 HCs [61.2% women]), perceived resilience was assessed by the Connor-Davidson Resilience Scale (CDRISC) and Brief Resilience Scale (BRS); relative resilience was assessed by the standardized residual of the Short Form-12 mental component summary score predicted by the Adverse Childhood Experiences score. Non-rotated partial least squares analysis of region-to-region resting-state connectivity data was used to define resilience-related signatures in HCs. Disease and sex-related differences within these signatures were investigated.

KEY RESULTS

Scores on all resilience measures were lower in IBS than in HCs (p's < 0.05). In all three resilience-related signatures, patients with IBS showed reduced connectivity largely involving the central autonomic network (p's < 0.001). Men with IBS showed lower CDRISC scores than women with IBS, and greater reductions in CDRISC-related connectivity, associated with worse symptom severity (p < 0.05).

CONCLUSIONS AND INFERENCES

Individuals with IBS show reduced perceived and relative resilience, with reduced connectivity suggesting impaired homeostasis maintenance. Men with IBS may show additional impairment in specific aspects of resilience. Treatments aimed at improving resilience may benefit patients with IBS, especially men with IBS.

Conceptualizing psychological resilience through resting-state functional MRI in a mentally healthy population: a systematic review

Conceptualizations and operational definitions of psychological resilience vary across resilience neuroimaging studies. Data on the neural features of resilience among healthy individuals has been scarce. Furthermore, findings from resting-state functional magnetic resonance imaging (fMRI) studies were inconsistent across studies. This systematic review summarized resting-state fMRI findings in different modalities from various operationally defined resilience in a mentally healthy population. The PubMed and MEDLINE databases were searched. Articles that focused on resting-state fMRI in relation to resilience, and published before 2022, were targeted. Orbitofrontal cortex, anterior cingulate cortex, insula and amygdala, were reported the most from the 19 included studies. Regions in emotional network was reported the most from the included studies. The involvement of regions like amygdala and orbitofrontal cortex indicated the relationships between emotional processing and resilience. No common brain regions or neural pathways were identified across studies. The emotional network appears to be studied the most in association with resilience. Matching fMRI modalities and operational definitions of resilience across studies are essential for meta-analysis.

Psychological resilience mediates the protective role of default-mode network functional connectivity against COVID-19 vicarious traumatization

Vicarious traumatization (VT), a negative reaction to witnessing others' trauma, has been experienced by some people during the COVID-19 pandemic, and can lead to mental health problems. This study aimed to identify functional brain markers of COVID-specific VT and explore the psychological mechanism underlying the brain-VT link. One hundred healthy participants underwent resting-state functional magnetic resonance imaging before the pandemic (October 2019-January 2020) and completed VT measurement during the pandemic (February-April 2020). Whole-brain correlation analysis based on global functional connectivity density (FCD) mapping revealed that VT was negatively correlated with FCD in the right inferior temporal gyrus (ITG) (i.e., the lower FCD in ITG, the worse the VT), identified by mapping onto known large-scale networks as part of the default-mode network (DMN). Resting-state functional connectivity (RSFC) analysis using ITG as seed found that VT was predicted by lower functional connectivity between ITG and other DMN regions including left medial prefrontal cortex, left orbitofrontal cortex, right superior frontal gyrus, right inferior parietal lobule and bilateral precuneus (i.e., the lower the ITG-DMN connectivity, the worse the VT). Mediation analyses suggested that psychological resilience served as a mediator in these associations of ITG FCD and ITG-DMN RSFC with VT. Our results provide novel evidence on the brain basis of VT and emphasize psychological resilience as an important link from DMN functional connectivity to COVID-specific-VT. This may facilitate public health interventions by helping identify individuals at risk of stress- and trauma-related psychopathologies.

Brain system segregation and pain catastrophizing in chronic pain progression

Pain processing involves emotional and cognitive factors that can modify pain perception. Increasing evidence suggests that pain catastrophizing (PC) is implicated, through pain-related self-thoughts, in the maladaptive plastic changes related to the maintenance of chronic pain (CP). Functional magnetic resonance imaging (fMRI) studies have shown an association between CP and two main networks: default mode (DMN) and dorsoattentional (DAN). Brain system segregation degree (SyS), an fMRI framework used to quantify the extent to which functional networks are segregated from each other, is associated with cognitive abilities in both healthy individuals and neurological patients. We hypothesized that individuals suffering from CP would show worst health-related status compared to healthy individuals and that, within CP individuals, longitudinal changes in pain experience (pain intensity and affective interference), could be predicted by SyS and PC subdomains (rumination, magnification, and helplessness). To assess the longitudinal progression of CP, two pain surveys were taken before and after an in-person assessment (physical evaluation and fMRI). We first compared the sociodemographic, health-related, and SyS data in the whole sample (no pain and pain groups). Secondly, we ran linear regression and a moderation model only in the pain group, to see the predictive and moderator values of PC and SyS in pain progression. From our sample of 347 individuals (mean age = 53.84, 55.2% women), 133 responded to having CP, and 214 denied having CP. When comparing groups, results showed significant differences in health-related questionnaires, but no differences in SyS. Within the pain group, helplessness (β = 0.325; p = 0.003), higher DMN (β = 0.193; p = 0.037), and lower DAN segregation (β = 0.215; p = 0.014) were strongly associated with a worsening in pain experience over time. Moreover, helplessness moderated the association between DMN segregation and pain experience progression (p = 0.003). Our findings indicate that the efficient functioning of these networks and catastrophizing could be used as predictors of pain progression, bringing new light to the influence of the interplay between psychological aspects and brain networks. Consequently, approaches focusing on these factors could minimize the impact on daily life activities.

Identifying resting state differences salient for resilience to chronic pain based on machine learning multivariate pattern analysis

Studies have documented behavior differences between more versus less resilient adults with chronic pain (CP), but the presence and nature of underlying neurophysiological differences have received scant attention. In this study, we attempted to identify regions of interest (ROIs) in which resting state (Rs) brain activity discriminated more from less resilient CP subgroups based on multiple kernel learning (MKL). More and less resilient community-dwellers with chronic musculoskeletal pain (70 women, 39 men) engaged in structural and functional magnetic resonance imaging (MRI) scans, wherein MKL assessed Rs activity based on amplitude of low frequency fluctuations (ALFF), fractional amplitudes of low frequency fluctuations (fALFF), and regional homogeneity (ReHo) modalities to identify ROIs most salient for discriminating more versus less resilient subgroups. Compared to classification based on single modalities, multi-modal classification based on combined fALFF and ReHo features achieved a substantially higher classification accuracy rate (79%). Brain regions with the best discriminative power included those implicated in pain processing, reward, executive function, goal-directed action, emotion regulation and resilience to mood disorders though variation trends were not consistent between more and less resilient subgroups. Results revealed patterns of Rs activity that serve as possible biomarkers for resilience to chronic musculoskeletal pain.

Behavioral and neural correlates of social network size: The unique and common contributions of face recognition and extraversion

OBJECTIVES

Humans are inherently social creatures and can gain advantages from larger network size. Researches have shown that different cognitive and personality factors may result in individual differences of social network size (SNS). Here, we focused on whether face recognition ability and extraversion were related to SNS and the neural basis underlying the relations.

METHODS

Behaviorally, we adopted the face-inversion task, NEO personality inventory, and computerized SNS test to explore the relationships between face recognition, extraversion, and SNS. Neurally, we used resting state functional magnetic resonance imaging and fractional amplitude of low-frequency fluctuation (fALFF) analysis method to investigate the neural correlates of SNS and then revealed whether face recognition and extraversion were related to SNS relevant brain regions.

RESULTS

We found that individuals with better face recognition ability and more extraverted personality had larger size of social network. In addition, we found that SNS was positively associated with the fALFF in the ventromedial prefrontal cortex (vmPFC), right superior temporal sulcus, and precuneus. Interestingly, the fALFF in the vmPFC significantly correlated with face recognition ability.

CONCLUSIONS

Our study suggests that both face recognition and extraversion may be important correlates of SNS, and the underlying spontaneous neural substrates are partially dissociable.

Childhood abuse and borderline personality disorder features in Chinese undergraduates: the role of self-esteem and resilience

BACKGROUND

Although childhood abuse is considered to be related to borderline personality disorder (BPD), few studies have elaborated on the mediating role of self-esteem and resilience in it. Thus, the present study aimed to explore the potential mediating role of resilience and self-esteem between childhood abuse and BPD.

METHODS

This cross-sectional study was conducted with 4034 college students in Anhui Province, China. Participants were asked to complete Chinese versions of the following instruments: Childhood Trauma Questionnaire-Short Form (CTQ-SF), Mclean Screening Instrument for Borderline Personality Disorder (MSI-BPD), Connor-Davidson Resilience Scale (CD-RISC), and Rosenberg Self-Esteem Scale (RSES). Structural equation modeling (SEM) was used to test the mediation effects.

RESULTS

Resilience and self-esteem were found to be mediators of all three types of childhood abuse (emotional abuse, physical abuse and sexual abuse) when the types were examined separately; however, when all three types of childhood abuse were entered into the model simultaneously, neither the indirect effects nor direct effects of physical abuse or sexual abuse were found to be significant, only the association between emotional abuse and BPD features was partially mediated by resilience and self-esteem.

CONCLUSIONS

Self-esteem and resilience mediate the links between childhood abuse and BPD features, and emotional abuse is uniquely associated with BPD features.

Common neurobiological correlates of resilience and personality traits within the triple resting-state brain networks assessed by 7-Tesla ultra-high field MRI

Despite numerous studies investigating resilience and personality trials, a paucity of information regarding their neurobiological commonalities at the level of the large resting-state networks (rsNWs) remains. Here we address this topic using the advantages of ultra-high-field (UHF) 7T-MRI, characterized by higher signal-to-noise ratio and increased sensitivity. The association between resilience, personality traits and three fMRI measures (fractional amplitude of low-frequency fluctuations (fALFF), degree centrality (DC) and regional homogeneity (ReHo)) determined for three core rsNWs (default mode (DMN), salience (SN), and central executive network (CEN)) were examined in 32 healthy volunteers. The investigation revealed a significant role of SN in both resilience and personality traits and a tight association of the DMN with resilience. DC in CEN emerged as a significant moderator for the correlations of resilience with the personality traits of neuroticism and extraversion. Our results indicate that the common neurobiological basis of resilience and the Big Five personality traits may be reflected at the level of the core rsNWs.

Sex effects on cortical morphological networks in healthy young adults

Understanding sex-related differences across the human cerebral cortex is an important step in elucidating the basis of psychological, behavioural and clinical differences between the sexes. Prior structural neuroimaging studies primarily focused on regional sex differences using univariate analyses. Here we focus on sex differences in cortical morphological networks (CMNs) derived using multivariate modelling of regional cortical measures of volume and surface from high-quality structural MRI scans from healthy participants in the Human Connectome Project (HCP) (n = 1,063) and the Southwest University Longitudinal Imaging Multimodal (SLIM) study (n = 549). The functional relevance of the CMNs was inferred using the NeuroSynth decoding function. Sex differences were widespread but not uniform. In general, females had higher volume, thickness and cortical folding in networks that involve prefrontal (both ventral and dorsal regions including the anterior cingulate) and parietal regions while males had higher volume, thickness and cortical folding in networks that primarily include temporal and posterior cortical regions. CMN loading coefficients were used as input features to linear discriminant analyses that were performed separately in the HCP and SLIM; sex was predicted with a high degree of accuracy (81%-85%) across datasets. The availability of behavioral data in the HCP enabled us to show that male-biased surface-based CMNs were associated with externalizing behaviors. These results extend previous literature on regional sex-differences by identifying CMNs that can reliably predict sex, are relevant to the expression of psychopathology and provide the foundation for the future investigation of their functional significance in clinical populations.

Sex-linked neurofunctional basis of psychological resilience in late adolescence: a resting-state functional magnetic resonance imaging study

Psychological resilience refers to the ability to adapt effectively in the face of adversity, which is closely related to an individual's psychological and physical health and well-being. Although previous behavioural studies have shown sex differences in psychological resilience, little is known about the neural basis of sex differences in psychological resilience. Here, we measured amplitude of low-frequency fluctuations (ALFF) via resting-state functional magnetic resonance imaging to investigate the sex-linked neurofunctional basis of psychological resilience in 231 healthy adolescents. At the behavioural level, we replicated previous findings indicating that males are more resilient than females. At the neural level, we found sex differences in the relationship between psychological resilience and ALFF in the right orbitofrontal cortex (OFC). Specifically, males showed a positive correlation between psychological resilience and ALFF in the right OFC, while females showed a negative correlation in this region. The sex-specific association between psychological resilience and spontaneous brain activity might be dependent on differences in hormonal systems and brain development between male and female adolescents. Taken together, the results of our study might provide the first evidence of sex-specific neurofunctional substrates of psychological resilience in adolescents, emphasizing the vital role of sex effects in future psychological resilience-related studies.

Diverging roles of the anterior insula in trauma-exposed individuals vulnerable or resilient to posttraumatic stress disorder

Distinct brain alterations in response to traumatic events may render trauma-exposed individuals either resilient or vulnerable to posttraumatic stress disorder (PTSD). This study compared regional cerebral metabolic rate of glucose (rCMRglu) among trauma-exposed individuals with current PTSD (PTSD group, n = 61), those without current PTSD (Resilience/Recovery group, n = 26), and trauma-unexposed controls (Control group, n = 54). All participants underwent brain [¹⁸F]-fluorodeoxyglucose positron emission tomography (FDG-PET) scans. Voxel-wise group differences in rCMRglu among the three groups were evaluated. Associations between rCMRglu and both PTSD severity and resilience were examined. The rCMRglu in the right anterior insula and adjacent prefrontal and striatal areas was lower in the PTSD group, while higher in the Resilience/Recovery group, compared to the Control group. In addition, the lower glucose metabolism of these areas was associated with higher severity and less improvement in PTSD symptoms in the PTSD group, while the higher levels of rCMRglu were correlated with stronger resilience in the Resilience/Recovery group. This study suggests distinct roles of the anterior insula in response to trauma between the PTSD and Resilience/Recovery groups. Heightened rCMRglu in the anterior insular regions may reflect an underlying mechanism of resilience against traumatic stress, while reduced rCMRglu may indicate vulnerability to PTSD.

Distinct neural correlates of trait resilience within core neurocognitive networks in at-risk children and adolescents

Background

Most children who are exposed to threat-related adversity (e.g., violence, abuse, neglect) are resilient - that is, they show stable trajectories of healthy psychological development. Despite this, most research on neurodevelopmental changes following adversity has focused on the neural correlates of negative outcomes, such as psychopathology. The neural correlates of trait resilience in pediatric populations are unknown, and it is unclear whether they are distinct from those related to adversity exposure and the absence of negative outcomes (e.g., depressive symptomology).

Methods

This functional magnetic resonance imaging (fMRI) study reports on a diverse sample of 55 children and adolescents (ages 6-17 years) recruited from a range of stressful environments (e.g., lower income, threat-related adversity exposure). Participants completed a multi-echo multi-band resting-state fMRI scan and self-report measures of trait resilience and emotion-related symptomology (e.g., depressive symptoms). Resting-state data were submitted to an independent component analysis (ICA) to identify core neurocognitive networks (salience and emotion network [SEN], default mode network [DMN], central executive network [CEN]). We tested for links among trait resilience and dynamic (i.e., time-varying) as well as conventional static (i.e., averaged across the entire session) resting-state functional connectivity (rsFC) of core neurocognitive networks.

Results

Youth with higher trait resilience spent a lower fraction of time in a particular dynamic rsFC state, characterized by heightened rsFC between the anterior DMN and right CEN. Within this state, trait resilience was associated with lower rsFC of the SEN with the right CEN and anterior DMN. There were no associations among trait resilience and conventional static rsFC. Importantly, although more resilient youth reported lower depressive symptoms, the effects of resilience on rsFC were independent of depressive symptoms and adversity exposure.

Conclusions

The present study is the first to report on the neural correlates of trait resilience in youth, and offers initial insight into potential adaptive patterns of brain organization in the context of environmental stressors. Understanding the neural dynamics underlying positive adaptation to early adversity will aid in the development of interventions that focus on strengthening resilience rather than mitigating already-present psychological problems.

Reproducibility of R-fMRI metrics on the impact of different strategies for multiple comparison correction and sample sizes

Concerns regarding reproducibility of resting-state functional magnetic resonance imaging (R-fMRI) findings have been raised. Little is known about how to operationally define R-fMRI reproducibility and to what extent it is affected by multiple comparison correction strategies and sample size. We comprehensively assessed two aspects of reproducibility, test-retest reliability and replicability, on widely used R-fMRI metrics in both between-subject contrasts of sex differences and within-subject comparisons of eyes-open and eyes-closed (EOEC) conditions. We noted permutation test with Threshold-Free Cluster Enhancement (TFCE), a strict multiple comparison correction strategy, reached the best balance between family-wise error rate (under 5%) and test-retest reliability/replicability (e.g., 0.68 for test-retest reliability and 0.25 for replicability of amplitude of low-frequency fluctuations (ALFF) for between-subject sex differences, 0.49 for replicability of ALFF for within-subject EOEC differences). Although R-fMRI indices attained moderate reliabilities, they replicated poorly in distinct datasets (replicability < 0.3 for between-subject sex differences, < 0.5 for within-subject EOEC differences). By randomly drawing different sample sizes from a single site, we found reliability, sensitivity and positive predictive value (PPV) rose as sample size increased. Small sample sizes (e.g., < 80 [40 per group]) not only minimized power (sensitivity < 2%), but also decreased the likelihood that significant results reflect "true" effects (PPV < 0.26) in sex differences. Our findings have implications for how to select multiple comparison correction strategies and highlight the importance of sufficiently large sample sizes in R-fMRI studies to enhance reproducibility. Hum Brain Mapp 39:300-318, 2018. © 2017 Wiley Periodicals, Inc.

Concussion/mild traumatic brain injury-related chronic pain in males and females: A diagnostic modelling study

Pain is an unpleasant, complex, and perceived experience that places a significant burden on patients and clinicians. Its severity may be mediated by emotion, attitude, and environmental influences, and pain may be expressed differently in males and females. Traumatic brain injury (TBI) is frequently associated with chronic pain. This diagnostic modeling study examined sex differences in the construct of chronic pain in patients with delayed recovery from concussion/mild traumatic brain injury (mTBI).Data were collected from standardized questionnaires, neuroimaging records, and comprehensive clinical assessments. Bivariate associations were calculated using the Spearman correlation coefficient or analysis of variance. We established sex-specific stepwise multivariate linear regression models of factors associated with pain.Of the 94 participants diagnosed with mTBI (the mean age was 45.20 ± 9.94 years; 61.2% were males; the median time since injury was 197 days [interquartile range 139-416]), head/neck, and bodily pain were reported by 93% and 64%, respectively. No sex differences were identified in pain frequencies or severity. Pain was significantly associated with certain socio-demographic, injury-related, behavioral, and clinical variables. In the multivariable regression analysis, several determinants explained 60% of the pain variance in males and 46% in females.Pain is common in patients with delayed recovery from mTBI and is significantly associated with potentially modifiable clinical and nonclinical variables. Examining the multidimensional construct of pain in concussion/mTBI through a sex lens garners new directions for future longitudinal research on the pain mechanisms involved in postconcussion syndrome.