Functional changes of default mode network and structural alterations of gray matter in patients with irritable bowel syndrome: a meta-analysis of whole-brain studies.

Background: Irritable bowel syndrome (IBS) is a brain-gut disorder with high global prevalence, resulting from abnormalities in brain connectivity of the default mode network and aberrant changes in gray matter (GM). However, the findings of previous studies about IBS were divergent. Therefore, we conducted a meta-analysis to identify common functional and structural alterations in IBS patients. Methods: Altogether, we identified 12 studies involving 194 IBS patients and 230 healthy controls (HCs) from six databases using whole-brain resting state functional connectivity (rs-FC) and voxel-based morphometry. Anisotropic effect-size signed differential mapping (AES-SDM) was used to identify abnormal functional and structural changes as well as the overlap brain regions between dysconnectivity and GM alterations. Results: Findings indicated that, compared with HCs, IBS patients showed abnormal rs-FC in left inferior parietal gyrus, left lingual gyrus, right angular gyrus, right precuneus, right amygdala, right median cingulate cortex, and left hippocampus. Altered GM was detected in the fusiform gyrus, left triangular inferior frontal gyrus (IFG), right superior marginal gyrus, left anterior cingulate gyrus, left rectus, left orbital IFG, right triangular IFG, right putamen, left superior parietal gyrus and right precuneus. Besides, multimodal meta-analysis identified left middle frontal gyrus, left orbital IFG, and right putamen as the overlapped regions. Conclusion: Our results confirm that IBS patients have abnormal alterations in rs-FC and GM, and reveal brain regions with both functional and structural alterations. These results may contribute to understanding the underlying pathophysiology of IBS. Systematic review registration: https://www.crd.york.ac.uk/prospero, identifier CRD42022351342.

"I-just-wanna-get-by" hurts teachers and their work: Linking preschool teacher identity to work withdrawals in an emerging economy.

Motivation deficit in low- and middle-income countries (LMICs) has implications for teacher well-being and education outcomes. This study, utilizing the job demand resource (JD-R) theory, explores the role of teacher identity as a motivational resource that antecedes emotional labor strategies - deep acting and surface acting. We further examined the relationship between emotional labor strategies and teacher work withdrawals - presenteeism and lateness, and the intervening role of teacher emotional exhaustion. We tested our theoretical model using 574 preschool teachers in Ghana. We found that teacher identity relates positively to deep acting but negatively to surface acting. And that deep acting relates to work withdrawals negatively whilst surface acting is associated with them positively. Deep acting diminishes work withdrawals because of its capacity to prevent emotional exhaustion, but the mediation role of emotional exhaustion in surface acting and work withdrawal links was non-significant. Our study presents preliminary evidence from an emerging economy on the central role of teacher identity (motivation component) in emotion management in an attempt to reduce emotional strain, thereby lessening negative work behaviors.

The effect of seed location on functional connectivity: evidence from an image-based meta-analysis.

Introduction: Default mode network (DMN) is the most involved network in the study of brain development and brain diseases. Resting-state functional connectivity (rsFC) is the most used method to study DMN, but different studies are inconsistent in the selection of seed. To evaluate the effect of different seed selection on rsFC, we conducted an image-based meta-analysis (IBMA). Methods: We identified 59 coordinates of seed regions of interest (ROIs) within the default mode network (DMN) from 11 studies (retrieved from Web of Science and Pubmed) to calculate the functional connectivity; then, the uncorrected t maps were obtained from the statistical analyses. The IBMA was performed with the t maps. Results: We demonstrate that the overlap of meta-analytic maps across different seeds' ROIs within DMN is relatively low, which cautions us to be cautious with seeds' selection. Discussion: Future studies using the seed-based functional connectivity method should take the reproducibility of different seeds into account. The choice of seed may significantly affect the connectivity results.

Resting-state abnormalities in functional connectivity of the default mode network in migraine: A meta-analysis.

Migraine-a disabling neurological disorder, imposes a tremendous burden on societies. To reduce the economic and health toll of the disease, insight into its pathophysiological mechanism is key to improving treatment and prevention. Resting-state functional magnetic resonance imaging (rs-fMRI) studies suggest abnormal functional connectivity (FC) within the default mode network (DMN) in migraine patients. This implies that DMN connectivity change may represent a biomarker for migraine. However, the FC abnormalities appear inconsistent which hinders our understanding of the potential neuropathology. Therefore, we performed a meta-analysis of the FC within the DMN in migraine patients in the resting state to identify the common FC abnormalities. With efficient search and selection strategies, nine studies (published before July, 2022) were retrieved, containing 204 migraine patients and 199 healthy subjects. We meta-analyzed the data using the Anisotropic Effect Size version of Signed Differential Mapping (AES-SDM) method. Compared with healthy subjects, migraine patients showed increased connectivity in the right calcarine gyrus, left inferior occipital gyrus, left postcentral gyrus, right cerebellum, right parahippocampal gyrus, and right posterior cingulate gyrus, while decreased connectivity in the right postcentral gyrus, left superior frontal gyrus, right superior occipital gyrus, right orbital inferior frontal gyrus, left middle occipital gyrus, left middle frontal gyrus and left inferior frontal gyrus. These results provide a new perspective for the study of the pathophysiology of migraine and facilitate a more targeted treatment of migraine in the future.

Regional abnormalities of spontaneous brain activity in migraine: A coordinate-based meta-analysis.

Many resting-state functional magnetic resonance imaging (rs-fMRI) studies have explored abnormal regional spontaneous brain activity in migraine. However, these results are inconsistent. To identify the consistent regions with abnormal neural activity, we meta-analyzed these studies. We gathered whole-brain rs-fMRI studies measuring differences in the amplitude of low-frequency fluctuations (ALFF), fractional ALFF (fALFF), or regional homogeneity (ReHo) methods. Then, we performed a voxel-wise meta-analysis to identify consistent abnormal neural activity in migraine by anisotropic effect size seed-based d mapping (AES-SDM). To confirm the AES-SDM meta-analysis results, we conducted two meta-analyses: activation likelihood estimation (ALE) and multi-level kernel density analysis (MKDA). We found that migraine showed increased regional neural activities in the bilateral postcentral gyrus (PoCG), left hippocampus (HIP.L), right pons, left superior frontal gyrus (SFG.L), triangular part of right inferior frontal gyrus (IFGtriang.R), right middle frontal gyrus (MFG.R), and left precentral gyrus (PreCG.L) and decreased regional intrinsic brain activities were exhibited in the right angular gyrus (ANG.R), left superior occipital gyrus (SOG.L), right lingual gyrus (LING.R). Moreover, the meta-analysis of ALE further validated the abnormal neural activities in the PoCG, right pons, ANG.R, and HIP. Meta-regression demonstrated that headache intensity was positively associated with the abnormal activities in the HIP.L, ANG.R, and LING.R. These findings suggest that migraine is associated with abnormal spontaneous brain activities of some pain-related regions, which may contribute to a deeper understanding of the neural mechanism of migraine.

Early childhood educators' emotional labor and burnout in an emerging economy: The mediating roles of affective states.

The costs and benefits of preschool teachers' emotional labor on the quality of education manifest in how emotional labor relates to well-being. Building on the theoretical foundation of conservation of resources theory (COR), this study explores the influence of emotional labor on burnout and the intervening roles of affective states (i.e., positive and negative affect). Our hypotheses were tested using cross-sectional data from 574 preschool teachers in Ghana. The results suggest that surface acting induces emotional exhaustion whilst diminishing personal accomplishment, but deep acting reduces depersonalization. Further, negative affect mediated surface acting and dimensions of burnout relationships. Also, positive affect mediated surface acting and deep acting, and personal accomplishment links. Theoretical and practical implications as well as directions for further research have been discussed.

COVID-19 Pandemic and International Students' Mental Health in China: Age, Gender, Chronic Health Condition and Having Infected Relative as Risk Factors.

International students in China were among the first group of individuals to be affected by the COVID-19 pandemic. However, the pandemic's impact on their mental health is underexplored. This study-utilizing web-based survey data (N = 381), presents preliminary reports using ANOVA and MIMIC analytic approaches. Following the clinical demarcation of the 21-item version of the Depression Anxiety Stress Scales (DASS-21), we found 24.6%, 38.3%, and 43.6% of the students to suffer mild to extreme stress, anxiety, and depression, respectively. Female students reported significantly higher levels of stress and depression than males. Older students' reports of stress were more substantial than younger students. Students who reported having a relative infected with the virus (vs. those without) experienced significantly higher anxiety and stress. Those who reported having pre-existing chronic health condition(s) (vs. those without) also reported significantly higher stress, anxiety, and depression levels. Moreover, students with an exercise routine (vs. those without) experienced significantly lower levels of stress, anxiety, and depression. Last, our MIMIC model results indicate that foreign students' age, gender, chronic health status, and having a relative infected with the virus constitute significant risk factors explaining variations in foreign students' experience of psychological distress. Implications for international students' management have been thoroughly discussed.

A Cross-Temporal Meta-Analysis of Changes in Left-Behind Children's Mental Health in China.

A considerable body of research using the Mental Health Test (MHT) has explored the psychological repercussions of the physical separation of children from one or both parents as they pursue better economic prospects in cities. Generally, these studies compare the mental health status (MHS) between left-behind children (LBC) and non-left-behind children (NLBC). That notwithstanding, little is known about the real policy impact of these studies on the ground over the years. Using a relevant search strategy and selection criteria, we identified qualified studies (N = 102: 2004 to 2019). Cross-temporal meta-analysis (CTMA) was performed on these studies for dynamic trends. Our results demonstrate: (1) a slight but significant change in MHS of both LBC and NLBC, with LBC being significantly worse off over time; (2) a significant deterioration in MHS of LBC over time, particularly among left-behind boys (LBBs); (3) a stable and significant decline in MHS of left-behind junior high and elementary school students, respectively; and (4) a more substantial degradation in MHS of LBC with both parents absent compared with LBC with a parent present. The findings reveal that the efforts of, and collaboration among, researchers, policy experts and politicians are producing results. Nevertheless, more targeted research is needed to unearth the underlying issues that generate the differences among subpopulations of LBC to better inform pragmatic interventions for collective psychological wellness of LBC.

Alterations of regional spontaneous brain activities in anxiety disorders: A meta-analysis.

BACKGROUND: Recent resting-state functional magnetic resonance imaging studies have provided strong evidence of abnormal regional spontaneous brain activities among anxiety-disordered patients. However, the evidence has been divergent and inconclusive. Therefore, it is necessary to perform a meta-analysis identifying a common pattern of altered regional spontaneous brain activity for anxiety disorders. METHOD: Corresponding research of anxiety disorders, namely, whole-brain rs-fMRI studies that measured differences in regional homogeneity, amplitude of low-frequency fluctuations, or fractional amplitude of low-frequency fluctuations, were analyzed in this study. Overall, seven studies with 235 anxiety-disordered patients and 241 healthy controls were ultimately included in the meta-analysis. The meta-analysis was processed by seed-based d mapping. RESULTS: Compared with healthy controls, patients with anxiety disorders showed significantly decreased regional spontaneous brain activities in the right putamen, the right orbital inferior frontal gyrus, and the right temporal pole. No increases in regional spontaneous brain activities were detected in patients relative to the controls. LIMITATION: Limited number of available studies, only Asian samples, and insufficient information of sample characteristics. CONCLUSION: The present study suggests that anxiety disorders are associated with aberrant regional brain activity in areas connected with emotion processing, which extends our understanding of anxiety disorders' pathophysiology.

Amplitude of Low-Frequency Fluctuation in Multiple Frequency Bands in Tension-Type Headache Patients: A Resting-State Functional Magnetic Resonance Imaging Study.

Purpose: Tension-type headache (TTH), the most prevalent primary headache disorder, imposes an enormous burden on the people of the world. The quest to ease suffering from this neurological disorder has sustained research interest. The present study aimed at evaluating the amplitude of low-frequency oscillations (LFOs) of the brain in multiple frequency bands in patients with TTH. Methods: To address this question, 63 participants were enrolled in the study, including 32 TTH patients and 31 healthy controls (HCs). For all the participants, amplitude of low-frequency fluctuation (ALFF) was measured in six frequency bands (conventional frequency bands, 0.01-0.08 Hz; slow-2, 0.198-0.25 Hz; slow-3, 0.073-0.198 Hz; slow-4, 0.027-0.073 Hz; slow-5, 0.01-0.027 Hz; and slow-6, 0-0.01 Hz), and the differences between TTH patients and HCs were examined. To explore the relationship between the altered ALFF brain regions in the six frequency bands and the Visual Analog Scale (VAS) score in the TTH patients, Pearson's correlation analysis was performed. Results: In all the six frequency bands, a decreased ALFF value was detected, and regions showing reduced ALFF values were mostly located in the middle frontal gyrus and superior gyrus. A frequency-dependent alternating characterization of intrinsic brain activity was found in the left caudate nucleus in the slow-2 band of 0.198-0.25 Hz and in the right inferior frontal orbital gyrus in the slow-5 band of 0.01-0.027 Hz. For the correlation results, both the left anterior cingulate and paracingulate gyri and right superior parietal gyrus showed a positive correlation with the VAS score in the slow-4 frequency band of 0.027-0.073 Hz. Conclusion: The ALFF alterations in the brain regions of TTH patients are involved in pain processing. The altered LFOs in the multiple regions may help promote the understanding of the pathophysiology of TTH. These observations could also allow the future treatment of TTH to be more directional and targeted and could promote the development of TTH treatment.