Brain connectivity最新文献

Background: Brain development during the preschool period is complex and extensive and underlies ongoing behavioral and cognitive maturation. Increasing understanding of typical brain maturation during this time is critical to early identification of atypical development and could inform treatments and interventions. Previous studies have suggested mismatches between brain structural and functional development in later childhood and adolescence. The current study aimed to delineate the developmental matches and mismatches between brain measures from multiple magnetic resonance imaging modalities in young children. Methods: Brain volume, cortical thickness, fractional anisotropy, cerebral blood flow (CBF), amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo), and eigenvector centrality mapping (ECM) were included. Multi-modal neuroimages for 159 datasets from 67 typically developing preschoolers (2.0-7.6 years old) were collected and analyzed. Results: Functional measures (CBF, ECM, ReHo, ALFF) had similar developmental trajectories across regions, whereas development trajectories for brain volumes and cortical thickness were more heterogeneous. Furthermore, within individuals, brain volumes and cortical thickness were very good at predicting individual scans from prior longitudinal scans. Conclusions: These findings provide a more detailed characterization of the complex interplay of different types of brain development in the early years, laying the foundation for future studies on the impact of environmental factors and neurodevelopmental disorders on the development matches/mismatches patterns between brain areas and modalities.

Background: The brain's function changes during various activities, and numerous studies have explored this field. An intriguing and significant area of research is the brain's functioning during imagination and periods of inactivity. Objective: This study explores the differences in brain connectivity during music listening and imagination: by identifying distinct neural connectivity patterns and providing insights into the cognitive mechanisms underlying auditory imagination. Methods: Effective connectivity matrices were generated using generalized partial directed coherence (GPDC) and directed Directed Transfer Function (dDTF) methods applied to non-invasive electroencephalography data from these two conditions. Statistical tests were performed to illustrate the differences in brain connectivity, followed by the creation of brain graphs and the application of a non-parametric permutation test to demonstrate statistical significance. Data classification between listening to music and imagining it was performed using an Support Vector Machine (SVM) classifier with different feature vectors. Results: Combining features extracted from GPDC and dDTF achieved an accuracy of 71.3% while using GPDC and dDTF features individually yielded accuracies of 60% and 62.1%, respectively. Among all the graph's global features, only modularity and small-worldness showed statistically significant differences in dDTF and GPDC. Overall, findings reveal that information flows from the left hemisphere to the right hemisphere increases during music imagination compared with listening, highlighting distinct neural connectivity patterns associated with imaginative processes. Conclusion: The study provides novel insights into the distinct neural connectivity patterns during music listening and imagination, contributing to the broader understanding of cognitive processes associated with auditory imagination and perception.

Introduction: The concept of community structure, based on modularity, is widely used to address many systems-level queries. However, its algorithm, based on the maximization of the modularity index Q, suffers from degeneracy problem, which yields a set of different possible solutions. Methods: In this work, we explored the degeneracy effect of modularity principle on resting-state functional magnetic resonance imaging (rsfMRI) data, when it is used to parcellate the cingulate cortex using data from the Human Connectome Project. We proposed a new iterative approach to address this limitation. Results: Our results show that current modularity approaches furnish a variety of different solutions, when these algorithms are repeated, leading to different number of subdivisions for the cingulate cortex. Our new proposed method, however, overcomes this limitation and generates more stable solution for the final partition. Conclusion: With this new method, we were able to mitigate the degeneracy problem and offer a tool to use modularity in a more reliable manner, when applying it to rsfMRI data.

Introduction: Rumination in bipolar disorder (BD) is well documented. Recent neuroimaging studies highlight the role of the default mode network (DMN) in rumination, while few studies have evaluated the DMN activity in BD rumination, particularly the underlying neuroelectrophysiology. Methods: A total of 44 patients with depressed bipolar I disorder (BD-I) and 46 healthy controls underwent resting-state magnetoencephalography. Two core hubs of the DMN, the posterior cingulate cortex (PCC), and anterior medial prefrontal cortex, together with the dorsal medial prefrontal cortex (dmPFC) and the medial temporal lobe (MTL) subsystems, were identified as the regions of interest. The power envelope method was used to determine the alpha band's cross-subsystem functional connectivity (FC). After comparing the rumination and DMN FC between the groups, Spearman partial correlation analysis was performed to evaluate the relationship between aberrant FC and rumination in BD-I patients. Results: BD-I patients demonstrated more global rumination, including higher subcomponent scores of brooding and reflection. In addition, the alpha frequency FC of the PCC-dmPFC and dmPFC-MTL subsystems within the DMN was dramatically increased in the BD-I group. The former was strongly associated with reflection, whereas the latter was related to brooding. Conclusion: The findings suggest that the reflection and brooding components of rumination are selectively related to the alpha frequency FC of the PCC-dmPFC and dmPFC-MTL subsystems, respectively. These associations highlight the significance of DMN activities in rumination among BD-I patients and have implications for future rumination interventions.

Background: Functional magnetic resonance imaging (fMRI) has not previously been used to localize the swallowing functional area in repetitive transcranial magnetic stimulation (rTMS) treatment for poststroke dysphagia; Traditionally, the target area for rTMS is the hotspot, which is defined as the specific region of the brain identified as the optimal location for transcranial magnetic stimulation (TMS). This study aims to compare the network differences between the TMS hotspot and the saliva swallowing fMRI activation to determine the better rTMS treatment site and investigate changes in functional connectivity related to poststroke dysphagia using resting-state fMRI. Methods: Using an information-based approach, we conducted a single case study to explore neural functional connectivity in a patient with poststroke dysphagia before, immediately after rTMS, and 4 weeks after rTMS intervention. A total of 20 healthy participants underwent fMRI and TMS hotspot localization as a control group. Neural network alterations were assessed, and functional connections related to poststroke dysphagia were examined using resting-state fMRI. Results: Compared to the TMS-induced hotspots, the fMRI activation peaks were located significantly more posteriorly and exhibited stronger functional connectivity with bilateral postcentral gyri. Following rTMS treatment, this patient developed functional connection between the brainstem and the bilateral insula, caudate, anterior cingulate cortex, and cerebellum. Conclusion: The saliva swallowing fMRI activation peaks show more intense functional connectivity with bilateral postcentral gyri compared to the TMS hotspots. Activation peak-guided rTMS treatment improves swallowing function in poststroke dysphagia. This study proposes a novel and potentially more efficacious therapeutic target for rTMS, expanding its therapeutic options for treating poststroke dysphagia.

Background: Individuals with spider phobic (SP) fear show hypervigilance and amygdala hyperactivity toward fear-associated stimuli, which may promote the development of other anxiety disorders. The amygdala is a key region within the fear network, which is connected to the anxiety system, where the bed nucleus of the stria terminalis (BNST) plays a crucial role. However, the BNST's involvement in phobic fear is unknown. Therefore, this study investigated the association of phobic fear and anxiety on these regions' functional connectivity (FC) in SP compared to healthy controls (HC). Methods: 7T-functional MRI resting-state FC of 30 individuals with SP and 45 HC was assessed to detect network differences between these groups. The association of phobic fear severity, trait anxiety, and social anxiety on FC was explored using linear regressions combined with seed-to-voxel analyses with amygdala and BNST as primary seeds, corrected for age and sex. Results: In SP, phobic fear was associated with reduced FC between the left amygdala and the right supramarginal gyrus. In contrast, anxiety severity was related to increased FC between the right BNST and the left inferior frontal gyrus. Moreover, social anxiety was related to decreased FC between bilateral BNST and left precuneus. Conclusions: These findings show changes in FC in SP, connecting fear with altered activity in the BNST and amygdala. The results suggest that persistent anxiety in phobic fear is associated with abnormal brain function in these regions, potentially explaining susceptibility to anxiety disorders and processes involved in phobic fear, such as threat perception, avoidance, and salience.

Introduction: Recent addiction and obesity-related research suggests that episodic future thinking (EFT) can serve as a promising intervention to promote healthy decision-making. We used data from a pilot study to investigate the acute neural effects of EFT in alcohol use disorder (AUD). Because of the limitations of those data, we additionally used data from a previously published functional MRI (fMRI) study in which participants had not received any intervention for their AUD. Methods: In an out-of-scanner, guided interview, participants (n = 24; median age = 37.3 years; median AUDIT = 22.5) generated scenarios and cues about their future (EFT intervention, n = 15) or recent past (control episodic thinking [CET] control intervention, n = 9). Then, they performed both resting-state and task-based (delay discounting [DD]) fMRI. We used nodes from the default mode network and salience networks as well as the hippocampus to perform seed-based analyses of the resting-state data. The results then guided psychophysiological interaction analyses in the DD task. In addition, we used data from a larger, previously reported study as a "no intervention" group of AUD participants (n = 50; median age = 43.3; median Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) alcohol dependence score = 7) to reproduce and aid in interpreting our key findings. Results: EFT, but not CET, participants showed statistically improved DD rates-a behavioral marker for addiction. Resting-state analyses of the left hippocampus revealed connectivity differences in the frontal poles. The directionality of this difference suggested that EFT may reduce a hypo-connectivity relationship between these regions in AUD. We also found resting-state connectivity differences between the salience network and the right dorsolateral prefrontal cortex (R DLPFC), which then led us to discover R-to-L DLPFC psychophysiological interaction differences during DD. Moreover, the resting-state salience-to-DLPFC functional connectivity showed an inverse relationship to DD rate while hyperconnectivity between left and right DLPFC reflected slower reaction times during DD trials. Discussion: These findings suggest that previously noted benefits of EFT such as the improved DD replicated here might coincide with changes in neural connectivity patterns in AUD. The alterations in connectivity highlight potential mechanisms underlying the effectiveness of EFT in improving decision-making in AUD. Understanding these neural effects may contribute to the further development of targeted interventions for AUD and related disorders.

Introduction: While understanding other's action intention, mirror and mentalizing systems of human brain are successively activated in action perception and intention inference processes. Methods: To reveal the relationship between mirror and mentalizing systems during the two stages, this electroencephalogram study adopted the method of time-varying orthogonalized partial directed coherence (OPDC) to assess causal interaction between mirror and mentalizing networks during a "hand-cup interaction" action intention understanding task. Results: Task-related causal connectivity was found in gamma frequency band (30-45 Hz), primarily manifested as directed edges from sensorimotor to frontal areas in poststimulus 400-600 ms interval and directed links from frontal to parietal and temporal regions in 600-800 ms period. The analysis of event-related potential and source currents suggests that the change of inter-regional causality is related with functional transition of the brain from mirror matching to intention inference. The OPDC network modeling further finds that frontal area contains more inflow nodes in mirror network, whereas more outflow nodes in mentalizing network, with high betweenness centrality in temporally changing functional communities. Compared with intention-oriented actions, identification of unintelligible action intention particularly induces stronger OPDC from right superior frontal to inferior frontal gyrus and from sensorimotor to right frontotemporal regions during mentalizing inference process. Conclusion: These findings collectively suggest that, in the time ordering of information transfer within the directed networks, frontal area plays an important role of bridging hub between mirror and mentalizing systems, from maintaining and supervising perceptual information for mirror matching to controlling the mentalizing process for decoding other's action intention.

Introduction: The influence of the cerebellum in poststroke aphasia recovery is poorly understood. Despite the right cerebellum being identified as a critical region involved in both language and cognitive functions, little is known about functional connections between the cerebellum and bilateral cortical hemispheres following stroke. This study investigated the relationship between chronic poststroke naming deficits and cerebello-cerebral resting-state functional connectivity (FC). Methods: Twenty-five cognitively normal participants and 42 participants with chronic poststroke aphasia underwent resting-state functional magnetic resonance imaging. Participants with aphasia also underwent language assessment. We conducted regions of interest (ROI)-to-ROI analyses to investigate the FC between the right cerebellar Crus I/II (seed ROI; Cereb1r/Cereb2r) and bilateral cortical language regions and compared these results to cognitively normal controls. Single-subject connectivity parameters were extracted and used as independent variables in a stepwise multiple linear regression model associating Boston Naming Test (BNT) score with FC measures. Results: FC analyses demonstrated correlations between the right cerebellar Crus I/II and both left and right cortical regions for both cognitively normal controls and stroke participants. Additionally, aphasia severity and lesion load had an effect on the cerebello-cerebral network connectivity in participants with aphasia. In a stepwise multiple linear regression, controlling for aphasia severity, time poststroke and lesion load, FC between the right Cereb2-left Cereb1 (standardized beta [std B]= -0.255, p < 0.004), right Cereb2-right anterior MTG (std B = 0.259, p < 0.004), and the right Cereb2-left anterior STG (std B = -0.208, p < 0.018) were significant predictors of BNT score. The overall model fit was R² = 0.786 (p = 0.001). Conclusion: Functional connections between the right cerebellum and residual bilateral cerebral hemisphere regions may play a role in predicting naming ability in poststroke aphasia.