Stronger functional network connectivity and social support buffer against negative affect during the COVID-19 outbreak and after the pandemic peak

Structural and functional neural patterns among sub-threshold bulimia nervosa: Abnormalities in dorsolateral prefrontal cortex and orbitofrontal cortex

BACKGROUND

Disordered eating behaviors are prevalent among youngsters and highly associated with dysfunction in neurocognitive systems. We aimed to identify the potential changes in individuals with bulimia symptoms (sub-BN) to generate insights to understand developmental pathophysiology of bulimia nervosa.

METHODS

We investigated group differences in terms of degree centrality (DC) and gray matter volume (GMV) among 145 undergraduates with bulimia symptoms and 140 matched control undergraduates, with the secondary analysis of the whole brain connectivity in these regions of interest showing differences in static functional connectivity (FC).

RESULTS

The sub-BN group exhibited abnormalities of the right dorsolateral prefrontal cortex and right orbitofrontal cortex in both GMV and DC, and displayed decreased FC between these regions and the precuneus. We also observed that sub-BN presented with reduced FC between the calcarine and superior temporal gyrus, middle temporal gyrus and inferior parietal gyrus. Additionally, brain-behavioral associations suggest a distinct relationship between these FCs and psychopathological symptoms in sub-BN group.

CONCLUSIONS

Our study demonstrated that individuals with bulimia symptoms present with aberrant neural patterns that mainly involved in cognitive control and reward processing, as well as attentional and self-referential processing, which could provide important insights into the pathology of BN.

Association Between Negative Affect and Perceived Mortality Threat During the COVID-19 Pandemic: The Role of Brain Activity and Connectivity

The prevalence of the novel coronavirus (COVID-19) has been considered a major threat to physical and mental health around the world, causing great pressure and mortality threat to most people. The current study aimed to investigate the neurological markers underlying the relationship between perceived mortality threat (PMT) and negative affect (NA). We examined whether the regional amplitude of low-frequency fluctuations (ALFF) and resting-state functional connectivity (RSFC) before the COVID-19 outbreak (October 2019 to December 2019, wave 1) were predictive for NA and PMT during the mid-term of the COVID-19 pandemic (February 22 to 28, 2020, wave 2) among 603 young adults (age range 17-22, 70.8% females). Results indicated that PMT was associated with spontaneous activity in several regions (e.g., inferior temporal gyrus, medial occipital gyrus, medial frontal gyrus, angular gyrus, and cerebellum) and their RSFC with the distributed regions of the default mode network and cognitive control network. Furthermore, longitudinal mediation models showed that ALFF in the cerebellum, medial occipital gyrus, medial frontal gyrus, and angular gyrus (wave 1) predicted PMT (wave 2) through NA (wave 2). These findings revealed functional neural markers of PMT and suggest candidate mechanisms for explaining the complex relationship between NA and mental/neural processing related to PMT in the circumstance of a major crisis.

Altered effective connectivity between reward and inhibitory control networks in people with binge eating episodes: A spectral dynamic causal modeling study

BACKGROUND

Converging evidence points to the crucial role of brain connectivity involved in aberrant behavioral control and reward reactivity in the onset and maintenance of binge eating. However, the directional interaction pattern between brain's reward and inhibitory control systems in people with binge eating episodes is largely unknown.

METHODS

Resting-state fMRI data were collected from 36 adults with binge eating episodes (age: 19.05 ± 0.90) and 36 well-matched controls (age: 18.88 ± 0.78). We applied spectral dynamic causal modeling approach to estimate effective connectivity of the executive control network (ECN) and reward network (RN) with 15 predefined regions of interest, and investigate the between-group differences in directional connectivity.

RESULTS

Compared with controls, the positive connections within the ECN were significantly strengthened in individuals with binge eating episodes, while the negative connections from the ECN to RN and from the RN to ECN were significantly weakened. In adults with binge eating episodes, the RN→ECN connectivity was positively related to binge frequency even controlling for age, sex, and body mass index.

CONCLUSION

This study represents an important first step in addressing the role of directional integration between reward and inhibitory control networks in binge eating, and provides novel evidence that the ability of people with binge eating episodes to maintain a balance between inhibitory control and reward reactivity is decreased, as reflected by diminished bidirectional negative effects of prefrontal-subcortical circuitry at rest.

Intolerance of Uncertainty and Cognition in Breast Cancer Survivors: The Mediating Role of Anxiety

Cancer-related cognitive impairment (CRCI) is one of the most prevalent symptoms that breast cancer survivors experience. While cancer treatments are established contributors to CRCI, inter-individual differences in CRCI are not well understood. Individual differences in sensitivity to uncertainty are potential contributors to CRCI; however, no prior studies have attempted to examine this link in the context of breast cancer. To address the gap, we used preliminary findings from an ongoing cross-sectional study. A total of 38 women with stage I-III breast cancer (1-4 years post-treatment) were included in this study. Intolerance of uncertainty (IU) was assessed using the Intolerance of Uncertainty Scale. Self-reported cognitive function was assessed with the Neuro-QoL questionnaire. Anxiety was assessed using the Patient-Reported Outcomes Measurement System Bank. From this study, we found that anxiety mediates the association between IU and cognitive function of survivors. In other words, among post-menopausal breast cancer survivors, those with higher IU showed higher anxiety and consequently had lower cognitive function. This finding suggests that assessing IU may help predict the risk of CRCI. This study expands the current knowledge that addresses the importance of IU as a factor associated with cognitive health.

Assessing functional connectivity differences and work-related fatigue in surviving COVID-negative patients

The Coronavirus Disease 2019 (COVID-19) has affected all aspects of life around the world. Neuroimaging evidence suggests the novel coronavirus can attack the central nervous system (CNS), causing cerebro-vascular abnormalities in the brain. This can lead to focal changes in cerebral blood flow and metabolic oxygen consumption rate in the brain. However, the extent and spatial locations of brain alterations in COVID-19 survivors are largely unknown. In this study, we have assessed brain functional connectivity (FC) using resting-state functional MRI (RS-fMRI) in 38 (25 males) COVID patients two weeks after hospital discharge, when PCR negative and 31 (24 males) healthy subjects. FC was estimated using independent component analysis (ICA) and dual regression. When compared to the healthy group, the COVID group demonstrated significantly enhanced FC in the basal ganglia and precuneus networks (family wise error (fwe) corrected, pfwe < 0.05), while, on the other hand, reduced FC in the language network (pfwe < 0.05). The COVID group also experienced higher fatigue levels during work, compared to the healthy group (p < 0.001). Moreover, within the precuneus network, we noticed a significant negative correlation between FC and fatigue scores across groups (Spearman's ρ = -0.47, p = 0.001, r2 = 0.22). Interestingly, this relationship was found to be significantly stronger among COVID survivors within the left parietal lobe, which is known to be structurally and functionally associated with fatigue in other neurological disorders.

Knowing what you feel: Inferior frontal gyrus-based structural and functional neural patterns underpinning adaptive body awareness

BACKGROUND

Heightened body awareness (BA) is conducive for increasing understanding of bodily state and improves individuals' health and well-being. Although there has been cumulative research concentrating on the self-perceived tendency to focus on negatively valenced interoceptive sensations, the specific structural and functional neural patterns underlying BA and their role in the relationship between BA and individual well-being remain unclear.

METHODS

Voxel-based morphometry and whole brain functional connectivity analyses were conducted to examine the structural and functional neural patterns, respectively, in 686 healthy subjects. BA and subjective well-being were assessed using questionnaires.

RESULTS

BA was inversely related to gray matter volume of the right inferior frontal gyrus, opercular part (IFGoperc). Higher BA was correlated with enhanced IFGoperc-precuneus and IFGoperc-anterior supramarginal gyrus connectivities, and with decreased IFGoperc-lateral occipital cortex and IFGoperc-medial frontal cortex connectivities. The inferior frontal gyrus, triangular part (in the fronto-parietal task control network) acted as the hub that linked the sensory/somatomotor network, the default mode network, and the dorsal and ventral attention network. The IFGoperc-precuneus connectivity moderated the association between BA and subjective well-being.

LIMITATIONS

We were unable to rank all the networks by their relative importance, because the absolute weighted value in each module was not calculated.

CONCLUSION

Our findings demonstrated that BA was reflected by specific neural patterns mainly involved in cognitive-affective control, attentional and self-referential processing, as well as multisensory integration, which could offer some references for current therapies (e.g., mindfulness, yoga training) that are dedicated to solving health problems and improving individual well-being.

Social Disconnectedness and Mental Health Problems During the COVID-19 Pandemic in China: A Moderated Mediation Model

Objectives: This study aimed to examine the mediating effect of perceived isolation and the moderating effect of COVID-19 related concerns in the relationship between social disconnectedness and mental health problems during the COVID-19 pandemic in China.

Methods: A cross-sectional online survey of 11,682 Chinese residents were conducted during the COVID-19 outbreak. Conditional process analysis was performed to test the mediating effect of perceived isolation and the moderating effect of COVID-19 related concerns.

Results: Social disconnectedness was positively related to mental health problems, and perceived isolation significantly mediated their relationship. COVID-19 related concerns exacerbated the direct link between social disconnectedness and mental health problems as well as the indirect link via perceived isolation.

Conclusion: Social disconnectedness was a key predictor of mental health problems during the COVID-19 outbreak. The direct and indirect effects of social disconnectedness on mental health problems were stronger for respondents who had more COVID-19 related concerns. Understanding the underlying mechanisms by which social disconnectedness is related to mental health problems has important practical implications for the prevention of mental health problems during the COVID-19 pandemic.

Changes in the Intranetwork and Internetwork Connectivity of the Default Mode Network and Olfactory Network in Patients with COVID-19 and Olfactory Dysfunction

Olfactory dysfunction (OD) is a common symptom in coronavirus disease 2019 (COVID-19) patients. Moreover, many neurological manifestations have been reported in these patients, suggesting central nervous system involvement. The default mode network (DMN) is closely associated with olfactory processing. In this study, we investigated the internetwork and intranetwork connectivity of the DMN and the olfactory network (ON) in 13 healthy controls and 22 patients presenting with COVID-19-related OD using independent component analysis and region of interest functional magnetic resonance imaging (fMRI) analysis. There was a significant correlation between the butanol threshold test (BTT) and the intranetwork connectivity in ON. Meanwhile, the COVID-19 patients with OD showed significantly higher intranetwork connectivity in the DMN, as well as higher internetwork connectivity between ON and DMN. However, no significant difference was found between groups in the intranetwork connectivity within ON. We postulate that higher intranetwork functional connectivities compensate for the deficits in olfactory processing and general well-being in COVID-19 patients. Nevertheless, the compensation process in the ON may not be obvious at this stage. Our results suggest that resting-state fMRI is a potentially valuable tool to evaluate neurosensory dysfunction in COVID-19 patients.

The cognitive basis of psychosocial impact in COVID-19 pandemic. Does it encircle the default mode network of the brain? A pragmatic proposal

Epigenetics, hypothalamic-pituitary axes, environmental and metabolic influences, and transgenerational plasticity govern social behavior. Cognitive research considers the brain's default mode network (DMN) as a central hub that integrates various cognitive and social processing domains responsible for emotion perception, empathy, theory of mind, and morality. Hence, DMN is regarded as the "social brain." Upsurge in social turmoil, social anxiety, panic, depression, post-traumatic stress, hoarding, herd behavior, substance and behavioral addictions, sexual abuse, and violence in the time of the COVID-19 pandemic are intricately related to personality traits resulting in disruptive social cognition and social behavior, conceptualized as the result of unsettling and disruption of the functional nexus of the DMN. Considering overt and conspicuous display of neuroticism during the current pandemic, its impact upon modulation of the DMN functional nexus and the DMN itself, and the potential to presage cognitive impairment in the future, the authors caution that an increase in the global burden of dementia may be one of the long-term ramifications of COVID-19. Social behavior, a functional derivative of the DMN, can strikingly affect the functional nexus of DMN and the DMN itself, in a centripetal way via the phenomenon called "Experience-Dependent Plasticity," with long-term consequences. In this review, we intend to 1) decipher the association between social cognition and social behavior with the DMN, in time of COVID-19; and to 2) discuss the prospective aftermath of disrupted social behavior during the pandemic on modulation/alteration of functional connectomes of DMN or the DMN itself in the time ahead.