Brain Topography最新文献

Exercise dependence is a behavioral disorder characterized by an obsessive and uncontrolled compulsion to exercise, which ultimately leads to detrimental outcomes for both physical health (e.g., injury, exhaustion) and mental state (e.g., anxiety, impaired social functioning). To investigate whether exercise-dependent individuals show altered brain network properties and if these properties relate to specific addictive behavioral tendencies. Resting-state EEG signals were collected from two groups of adult participants: individuals with a high risk of exercise dependence and those with a low risk, as classified using the Chinese version of the Exercise Dependence Scale (EDS). Source analysis and brain network graph-theory analysis were applied to examine key global and local network measures. The results show that group differences were observed in local graph measures (nodal degree of the right ventral prefrontal cortex and left temporal pole), which survived FDR correction, as well as in global graph measures (global clustering coefficient and small-worldness), which did not reach FDR-corrected significance but showed moderate effect sizes. Furthermore, the nodal degree of the left temporal pole, global clustering coefficient, and small-worldness were independently associated with the total score of the Chinese version of the EDS and correlated significantly with scores on specific sub-scales. The findings suggest that high EDS individuals demonstrate altered brain functional networks that are significantly associated with their specific addictive behavioral tendencies.

This randomized controlled trial investigated the effects of motor imagery training (MIT) monitored by functional near-infrared spectroscopy (fNIRS) on upper limb motor function and cortical activation in stroke patients. Seventy participants were allocated to either an MI group, which received conventional rehabilitation therapy (CRT) supplemented with visual and kinesthetic-based MIT, or a control group (CON group), which received CRT alone. The CRT intervention consisted of 30-min sessions administered four times per day over a 4-week period. The MI group underwent an additional daily 25-min session of MIT, whereas the CON group watched neutral nature documentaries (landscapes and animals) for an equivalent duration. Functional outcomes were assessed using the Fugl-Meyer Assessment for Upper Extremity (FMA-UE) and the modified Barthel Index (MBI). Additionally, fNIRS was used to monitor changes in oxyhemoglobin (HbO₂) levels in the motor cortex before and after the intervention in the MI group. Sixty-three participants completed the study (MI group: n = 32, CON group: n = 31). Both groups showed significant improvements in FMA-UE and MBI scores after the intervention (P < 0.05). The MI group demonstrated significantly greater improvement in MBI compared with the CON group (P < 0.05), although between-group differences in FMA-UE were not significant (P > 0.05). fNIRS revealed increased cortical activation in the MI group, specifically showing enhanced activation intensity in the supplementary motor area (channel 3) and sensorimotor cortex (channels 18, 19, 21) (P < 0.05). These findings suggest that functional improvements may be mediated through neural plasticity changes. The combined application of MIT and CRT appears to enhance motor cortex activation and promote functional recovery in stroke rehabilitation.

This study examined how different types of semantic relationships modulate cortical activity during spatial judgments in an augmented reality (AR) setting. Participants viewed triads of everyday objects that were either thematically (co-occurring) or functionally (sharing a purpose) related and made spatial judgments varying in reference frame, egocentric (object closest to you?) vs. allocentric (object closest to another? ), and relation type, coordinate (distance-based) vs.categorical (left-right). Cortical activity was measured using functional near-infrared spectroscopy (fNIRS). Results showed that semantic modulation was most evident during allocentric-coordinate judgments, with increased activation in temporal regions for thematic triads compared to functional ones. In general, functionally related triads engaged parietal regions more broadly across conditions, while egocentric judgments elicited widespread parietal activity with reduced semantic modulation. Finally, categorical judgments showed minimal differences between semantic conditions. By combining AR with fNIRS, this study provides evidence that semantic knowledge influences cortical recruitment during spatial processing, offering a novel window into how meaning and spatial representation interact.

Infrared neural stimulation (INS) represents an invasive technique for modulating brain activity in animals, particularly primates, which serve as effective models for human brain research. Noninvasive approaches, such as transcranial laser stimulation, are safer but have lower spatial and temporal resolution, primarily altering metabolic processes rather than directly stimulating specific neurons. Invasive techniques provide better resolution by targeting neurons with focused laser beams but require intricate surgeries that damage the meninges, limiting studies to short-term experiments conducted mostly on anesthetized animals. We present a minimally invasive approach for long-term, high-resolution laser INS that does not disrupt brain tissue integrity and minimizes the risk of inflammation. Laser radiation is delivered through contact between a flexible optical fiber and the outer surface of the dura mater, allowing for chronic experiments on non-anesthetized primates who maintain their cognitive functions and physical activities. This method has enabled us to conduct a multi-day INS experiment and collect statistically reliable data on neurophysiological responses in a cognitively intact primate subjected to targeted high-resolution INS. We analyzed electrocorticogram and evoked potentials in various cortical areas while applying infrared laser stimulation directed at a selected point on the primary visual cortex of a rhesus macaque. Results indicated that even low-intensity laser stimulation (below conscious perception thresholds) caused synchronous biopotential changes not only at the stimulation site but also in certain distant cortical regions, suggesting a more complex brain response mechanism to INS than merely the activation of stimulated neurons. We believe the presented method will significantly facilitate chronic INS studies, further contributing to fundamental and clinical outcomes.

This study investigated the neuromodulatory effects of 40 Hz rhythmic light (RL) versus a rhythmic light control condition (RLCC) on microstate dynamics in individuals classified with mild cognitive impairment (MCI) and healthy controls. This study employed a two-session, within-subjects design in which each participant completed both 40 Hz and RLCC sessions. EEG was recorded immediately before (pre) and during each RL session, while cognitive assessments were conducted pre and post each session. Twenty-four participants classified with MCI and 27 healthy controls were exposed to both light conditions and underwent electroencephalography recordings, cognitive performance testing (2-back task), and subjective sleepiness questionnaires (Karolinska Sleepiness Scale). We used microstate analysis to examine alterations in microstate dynamics in responses to each light condition. Microstate analysis revealed a reduction in the duration of microstate B and the occurrence rate of microstate C following 40 Hz RL stimulation, suggesting enhanced neural processing efficiency. Both MCI and control participants exhibited stable microstate configurations (A-D) across light conditions, with balanced coverage (~ 20-30%) and subtle shifts-particularly between microstates A and B-indicating dynamic brain state reorganization under 40 Hz stimulation, especially in the MCI group. 40 Hz RL may support compensatory neural mechanisms in individuals with MCI while enhancing sensory and cognitive processing in healthy aging individuals. These findings highlight the potential use of 40 Hz RL as a non-invasive intervention to modulate brain networks and promote cognitive function. Future longitudinal studies are needed to explore the sustained effects of 40 Hz RL on cognitive function and neural integrity in aging populations.

Inhibitory control is crucial for humans to select useful information from the complex environment. The bilateral DLPFC, which is implicated in inhibitory control, was activated under psychological stress. The present study investigated the influence of acute psychological stress on inhibitory control process using the color-word Stroop task. The stress was induced by the Trier Social Stress Task (TSST). After TSST (stress group) or placebo TSST (control group), the male participants performed a color-word Stroop task, and their brain activity was measured using functional near-infrared spectroscopy (fNIRS). The results showed that elevated subjective stress, heart rate, and salivary cortisol were found in the stress than control groups, indicating that the stress had been induced successfully. Reduced RT Stroop effect (RT_incongruent - RT_congruent) was found for the stress group compared to the control group. The fNIRS results revealed greater activation in bilateral dorsolateral prefrontal cortex (DLPFC) in the stress than control groups. In addition, the activation in left DLPFC was increased for the stress than control groups in incongruent trials, but not in the congruent trials, resulting in a larger magnitude of the activation Stroop effect (activation_incongruent - activation_congruent) in the stress group. These results demonstrate that acute psychological stress may potentially improve inhibitory control in healthy men.

Accumulating evidence has revealed deviations in neural network connectivity among individuals with suicidal ideation (SI). We sought to explore the neural network dynamics of suicide attempt (SA) survivors. We recruited 31 SA survivors, 33 individuals with SI, and 33 normal people controls (NP). To investigate brain network dynamics, we collected 64-channel resting-state EEG recordings and conducted microstate analysis on all participants. Compared to the NP group, both SA survivors and SI group displayed greater coverage and occurrence of microstates A and B. Notably, relative to the SI group, a marked elevation in the occurrence of microstates D and E and a significant increased coverage of microstate E, were observed in the SA group. The SA group exhibited significantly shorter durations of microstates C, D, and E, along with reduced occurrence and coverage of microstate C, compared to the SI group. The SA group exhibited significantly greater transition probabilities from microstate E to any other microstate compared to the SI group. Furthermore, higher suicide risk scores significantly correlated increased occurrence of microstate D, occurrence of microstate E, and coverage of microstate E. A key limitation is the cross-sectional design, which restricts the capacity to establish whether microstate dynamics can serve as predictors of future suicidal behavior. The present results imply that the microstate dynamics of SA survivors are distinct from those of individuals with SI. These results indicate that microstate dynamics could potentially act as neurobiomarkers for distinguishing suicidal behavior and SI.

Functional magnetic resonance imaging (fMRI) is a valuable neuroimaging tool for studying brain function and connectivity. However, the blood oxygen level dependent (BOLD) signal used in fMRI is affected by various physiological factors, such as cardiac and respiratory activity, which can influence functional connectivity patterns. As such, physiological noise correction is a crucial preprocessing step in fMRI data analysis. When concurrent physiological recordings are available, researchers often generate nuisance regressors to account for the effect of heart rate and respiratory variations by convolving physiological response functions (PRF) with the corresponding physiological signals. However, it has been suggested that the PRF characteristics may vary across subjects and different regions of the brain, as well as across scans of the same subject. To explore this variability, we examine the performance of several different PRF models, in terms of BOLD variance explained, using resting-state fMRI data from the Human Connectome Project (N = 100). We examined both one-input (heart rate or respiration) and two-input (heart rate and respiration) PRF models and show that allowing PRFs to vary across subjects and brain regions generally improves PRF model performance. For one-input models, the improvement in model performance gained by allowing spatial variability was most prominent for respiration, particularly for a subset of the subjects (about a third) examined. Subject-specific or regional variability in cardiac response only enhanced performance when using two-input models. Overall, our results highlight the importance of considering spatial and subject-specific variability in PRFs when analyzing fMRI data, particularly regarding respiratory-related fluctuations.

Cancer-related fatigue (CRF) significantly diminishes the quality of life of cancer survivors; however, objective diagnostic markers and the underlying neurophysiological mechanisms remain unclear. This study aimed to identify noninvasive EEG-based biomarkers of CRF by examining cortical activity and functional connectivity. We recorded resting-state and task-related [repetitive submaximal elbow flexions (EFs) until self-perceived exhaustion] high-density electroencephalography (EEG) from 10 cancer survivors with CRF and 14 healthy controls (HC). In our analysis, task-induced fatigue was categorized as mild, moderate, and severe, corresponding to the level of fatigue perceived at the beginning, middle, and end of the task period. Our study revealed the following significant findings: (1) Linear mixed-effects modeling of event-related desynchronization (ERD) EEG analysis during the EF task demonstrated significant effects of group and fatigue levels in the alpha band (8-12 Hz). (2) EF task-specific functional connectivity was estimated using the debiased weighted phase-lag index (dwPLI), which demonstrated reduced inter-regional connectivity in the M1 and prefrontal regions in the CRF group compared with the HC group. (3) The dwPLI analysis identified significantly reduced alpha-band connectivity strength in the CRF group, particularly between the right supramarginal gyrus and other brain regions during mild fatigue. (4) Additionally, resting-state EEG exhibited globally elevated delta-band (1-4 Hz) activity in CRF survivors than HC, potentially reflecting chronic fatigue. These observations emphasize the clinical relevance of resting-state EEG, motor activity-related ERD and functional brain connectivity as potential CRF biomarkers. Future research should validate these findings in larger cohorts and provide insights into more objective CRF diagnosis and the development of personalized interventions for alleviating CRF.

To advance the application of functional near-infrared spectroscopy (fNIRS) in brain-computer interface (BCI) technology, we investigated cortical activation patterns associated with auditory selective attention. Using a dichotic listening paradigm, participants were presented with simultaneous music and reading sounds to the left or right ear. During fNIRS recordings, they were instructed to selectively attend to the sound attribute (music vs. reading) or the spatial location (left vs. right ear). Cortical activity differences related to attentional targets were analyzed using a two-way analysis of variance (ANOVA), with sound attribute and spatial information as factors. Our results revealed a significant main effect of the sound attribute factor across multiple measurement channels. Notably, the right parietal region exhibited consistently greater activation when attention was directed toward music compared to reading sounds. Conversely, bilateral dorsolateral prefrontal cortex (DLPFC) channels showed higher activation when participants attended to reading sounds than to music. These findings indicate that cortical activation patterns are modulated by auditory attentional states based on sound attributes. Furthermore, preliminary classification analyses achieved an accuracy of 73.7% in discriminating attentional targets (music vs. reading sounds), demonstrating the feasibility of fNIRS-based BCI applications.