Most recent paper
Adverse childhood experiences and resting state functional connectivity of the triple brain network: a meta-analysis
Eur Arch Psychiatry Clin Neurosci. 2026 Feb 12. doi: 10.1007/s00406-026-02204-2. Online ahead of print.
NO ABSTRACT
PMID:41677825 | DOI:10.1007/s00406-026-02204-2
Exercise-Induced modulation of molecular-enriched functional connectivity in Parkinson's disease
J Parkinsons Dis. 2026 Feb 12:1877718X261420080. doi: 10.1177/1877718X261420080. Online ahead of print.
ABSTRACT
Parkinson's disease (PD) involves degeneration of dopaminergic neurons and dysfunction across multiple neurotransmitter systems, contributing to both motor and cognitive impairments. Aerobic exercise improves clinical outcomes; however, its underlying neural mechanisms remain unclear. Using conventional resting-state fMRI combined with Receptor-Enriched Analysis of functional Connectivity by Targets (REACT), we examined molecular-enriched motor network changes following six months of supervised aerobic training in PD. Exercise-related connectivity changes were inversely correlated with baseline PD-healthy control differences, reflecting a partial normalization of PD-altered motor networks. Molecular-enriched analyses revealed selective effects on dopaminergic (FDOPA-enriched) and cholinergic (VAChT-enriched) related networks, with no changes observed in networks associated with serotonergic or noradrenergic systems. These findings provide supporting evidence for potential mechanistic links between aerobic exercise and network reorganization in PD, highlight multisystem effects, and illustrate the utility of molecular-enriched fMRI for probing neurotransmitter-specific interventions.
PMID:41677133 | DOI:10.1177/1877718X261420080
A multi-session simultaneous EEG-fMRI dataset with repeated experience sampling
bioRxiv [Preprint]. 2026 Feb 7:2026.02.04.703882. doi: 10.64898/2026.02.04.703882.
ABSTRACT
The integration of electroencephalography (EEG) and functional Magnetic Resonance Imaging (fMRI) can be used to characterize temporal and spatial components of neural activity during unfolding mental experience. Here we introduce a multi-session simultaneous EEG-fMRI dataset with measures of continuous behavior and spontaneous mental experience. Data components, organized in Brain Imaging Dataset Structure (BIDS) format, include fMRI, EEG with carbon wire loop sensors for artifact removal, continuous performance task responses, experience sampling ratings, and mental health surveys, from 24 healthy adults. Tasks included the gradual-onset continuous performance task and resting state with intermittent experience sampling of 13 unique thought dimensions (36 repetitions, including 468 total ratings, per participant). The same protocol was completed on two different days, yielding approximately 1.33 hours of simultaneous EEG-fMRI data per individual. The dataset may be used to explore the behavioral and experiential relevance of brain activity during the wakeful resting state. The dataset also provides a means to study the reliability of relationships between fMRI and EEG features across sessions within individuals.
PMID:41676676 | PMC:PMC12889718 | DOI:10.64898/2026.02.04.703882
Individualized Mapping of Functional Brain Networks in Older Adulthood
bioRxiv [Preprint]. 2026 Feb 2:2026.01.30.702883. doi: 10.64898/2026.01.30.702883.
ABSTRACT
The functional network architecture of the aging brain undergoes significant systematic and idiosyncratic changes. Emergent individualized network mapping approaches may yield better or more sensitive explanatory insight about age-related neural and behavioral variability, although most applications have focused on young adults. In the current study, we tested the validity and impact of mapping individual-specific topography in two fMRI datasets comprising 112 young (18-35 years) and 176 older adults (60-92 years). Older adults had more idiosyncratic network topography than young adults. Individualized maps from resting-state fMRI improved network homogeneity and fidelity to task fMRI activations, while also exhibiting intra-individual reliability and inter-individual discriminability over a 2-year interval. Last, traditional group-averaged ( vs . individualized) network mapping had a moderate-to-large impact on individual-level estimates of network segregation, a widely-studied measure of functional brain aging. Therefore, individualized network mapping captures important heterogeneity in older adulthood and may yield more precise characterization of neurocognitive aging.
PMID:41676650 | PMC:PMC12889444 | DOI:10.64898/2026.01.30.702883
Multi-echo BOLD fMRI improves cerebrovascular reactivity estimates in stroke
bioRxiv [Preprint]. 2026 Feb 6:2026.02.03.703581. doi: 10.64898/2026.02.03.703581.
ABSTRACT
Cerebrovascular reactivity (CVR), the ability of cerebral blood vessels to dilate or constrict in response to a vasoactive stimulus, is a clinically meaningful measure of cerebrovascular health. Head motion and other noise sources substantially impact CVR quality, particularly in clinical populations. In this study, we evaluated multi-echo fMRI techniques, including optimal combination of echoes (ME-OC) and multi-echo independent component analysis (ME-ICA), for improving CVR quality relative to single-echo fMRI in participants with stroke. In a breath-hold fMRI dataset, ME-OC significantly improved CVR quality metrics and reduced the percentage of negative CVR values in normal-appearing gray and white matter ( p <0.05). ME-ICA reduced the dependence of BOLD signals on head motion but did not improve CVR quality metrics. In a separate resting-state dataset, ME-OC effects were largely consistent with the breath-hold dataset, but ME-ICA also significantly improved CVR quality metrics and reduced negative CVR values in normal-appearing gray and white matter relative to ME-OC ( p <0.05). These findings demonstrate that multi-echo fMRI can improve CVR estimation in clinical populations, particularly in low signal-to-noise datasets, enhancing the feasibility of CVR analyses in stroke studies and allowing for better visualization of stroke-related CVR deficits.
PMID:41676635 | PMC:PMC12889588 | DOI:10.64898/2026.02.03.703581
Symmetric Fusion of fMRI and EEG for Spectrally Resolved Functional Neuroimaging
bioRxiv [Preprint]. 2026 Feb 3:2026.01.31.703060. doi: 10.64898/2026.01.31.703060.
ABSTRACT
Simultaneous electroencephalography (EEG) and functional MRI (fMRI) offers complementary sensitivity to fast electrophysiological dynamics of EEG and spatially resolved hemodynamics of fMRI, yet previous joint-analysis approaches are confined to fixed task paradigms and struggle with continuous or naturalistic brain states. We FSINC (Fusing Source Imaging based on a Neurovascular Coupling) model, a unified EEG-fMRI source imaging framework that reconstructs cortical activity to simultaneously explain both modalities. FSINC integrates frequency-resolved EEG source activity with fMRI via a data-driven neurovascular coupling model that estimates band-specific coupling coefficients (β) and accommodates a tunable spatial-temporal trade-off through hyperparameters ( λ 2 , λ 3 ). In realistic simulations, FSINC outperformed conventional methods (wMNE, LORETA) in both spatial and temporal accuracy across EEG SNRs (-10 to 10dB) and numbers of concurrent sources (up to five), with optimal performance at λ 2 = 10 2 and λ 3 =1 (e.g., LE: 0.51±0.24mm; SDI: 0.03±0.37mm; temporal accuracy: 0.95 ± 0.05). Applied to simultaneous EEG-fMRI during contrast-reversing visual stimulation (=5.95Hz), FSINC revealed stimulus-locked responses localized to early visual cortex and stimulus-induced modulation of intrinsic alpha oscillations extending into visual and attention networks, patterns that conventional methods failed to capture. Estimated β-weights were broadly consistent with prior reports of negative (theta/alpha) and positive (gamma) BOLD-electrophysiology associations. These findings demonstrate that FSINC enables high-spatiotemporal-resolution source imaging from EEG-fMRI recordings via data-driven hemodynamic modelling, and is expected to be well-suited for continuous and naturalistic brain states (e.g., resting state, natural moving-watching, and narrative listening) that are difficult to interrogate with either modality alone.
PMID:41676576 | PMC:PMC12889465 | DOI:10.64898/2026.01.31.703060
Connectomes across temporal scales with simultaneous wide-field optical imaging and resting-state functional MRI
bioRxiv [Preprint]. 2026 Feb 3:2026.02.01.703149. doi: 10.64898/2026.02.01.703149.
ABSTRACT
Resting-state functional MRI (rs-fMRI) is a cornerstone of human brain research, yet its interpretation is complicated by its sensitivity to the slow hemodynamic response that obscures the organization of neural activity across faster time scales. Here we use simultaneous wide-field optical imaging (WOI) and rs-fMRI to directly examine the relationship between neural and hemodynamic functional connectomes across time scales. We show that much of the large-scale spatial structure is preserved across modalities, across time scales, and across frequencies. Although rs-fMRI robustly captures time-averaged neural activity, time-resolved rs-fMRI estimates of functional connectivity exhibit significantly greater variability, which partially reflects sensitivity limitations. Hemodynamic WOI signals maintain greater similarity to neural activity than rs-fMRI, although their fidelity is reduced at high frequencies. Together, our findings demonstrate that the time-averaged spatial structure of neural activity is faithfully represented in hemodynamics and rs-fMRI; provide insight into the reliability of time-resolved rs-fMRI across temporal scales; and establish a multimodal framework for validating features of dynamic brain activity.
PMID:41676555 | PMC:PMC12889463 | DOI:10.64898/2026.02.01.703149
Investigating White Matter Functional Network Connectivity Across the Alzheimers Disease Spectrum Using Resting-State fMRI
bioRxiv [Preprint]. 2026 Feb 7:2026.02.04.703913. doi: 10.64898/2026.02.04.703913.
ABSTRACT
White matter (WM) has traditionally been considered structurally important but functionally inert in fMRI research. However, growing evidence indicates that WM exhibits meaningful BOLD fluctuations and participates in functional connectivity. Here, we investigate alterations in WM functional network connectivity (FNC) across the Alzheimers disease (AD) spectrum using resting-state fMRI data from the Alzheimers Disease Neuroimaging Initiative (ADNI 415 cognitively normal (CN), 283 mild cognitive impairment (MCI), 91 AD). We applied a guided independent component analysis (ICA) approach based on a combined multiscale template including 202 intrinsic connectivity networks (ICNs; 97 WM, 105 gray matter (GM)) to estimate subject-specific timecourses and compute static FNC (sFNC). Group differences in WMWM, GMGM, and WMGM connectivity (ADCN, ADMCI, MCICN) were assessed using two-sample t-tests with covariates for age, sex, and motion, with false discovery rate correction. Results showed robust alterations in WMWM and WMGM connectivity in AD, particularly involving WM subcortical, frontal, sensorimotor, and occipitotemporal networks. Several WMGM interactions with cerebellar and hippocampal GM networks were also disrupted, including reduced GMcerebellar:WMfrontal coupling and increased GMhippocampal to WMfrontal connectivity. Notably, MCI already showed WMGM dysconnectivity relative to CN, suggesting that functional disruption of WM circuits emerges prior to overt dementia. These findings provide converging evidence that WM functional connectivity is both measurable and selectively altered across the AD continuum. Our findings support WM sFNC as a complementary candidate biomarker to GM-based measures for staging and monitoring AD. This is, to our knowledge, the first large-scale ADNI study to jointly model WM and GM intrinsic connectivity networks and quantify WMGM dysconnectivity across CN, MCI, and AD.
PMID:41676490 | PMC:PMC12889614 | DOI:10.64898/2026.02.04.703913
Association between left precuneus functional connectivity and early neurodevelopment in preterm infants
Brain Dev. 2026 Feb 10;48(2):104513. doi: 10.1016/j.braindev.2026.104513. Online ahead of print.
ABSTRACT
OBJECTIVE: Preterm birth is associated with an increased risk of functional brain network alterations, which may contribute to long-term motor and neurocognitive deficits. However, the underlying neural mechanisms remain incompletely understood. This study aimed to investigate functional brain activity changes in preterm infants and their correlation with early neurobehavioral development.
METHODS: Fifteen preterm infants and 15 full-term infants underwent scanning using a 3.0T Philips MRI scanner. Three resting-state functional magnetic resonance imaging (rs-fMRI) data-driven approaches, amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo), and seed-based functional connectivity (FC) were used to comprehensively evaluate functional brain alterations in preterm infants at term-equivalent age (TEA). Correlations between Neonatal Behavioral Neurological Assessment (NBNA) scores and FC values of abnormally connected brain regions were further analyzed in preterm infants at TEA.
RESULTS: Compared with full-term infants, preterm infants exhibited significantly higher ALFF and ReHo values in the left precuneus. Using the left precuneus as a seed region for FC analysis, preterm infants showed reduced FC with the left Rolandic operculum, right putamen, and left hippocampus. Additionally, FC values between the left precuneus and left Rolandic operculum, as well as between the left precuneus and right putamen, were positively correlated with NBNA scores in preterm infants.
CONCLUSIONS: Preterm infants may present early functional connectivity impairments of the left precuneus, which may be a potential neural correlate of neurobehavioral abnormalities. These findings provide insights into the neurodevelopmental mechanisms underlying preterm birth-related deficits and may inform early clinical assessment strategies.
PMID:41671832 | DOI:10.1016/j.braindev.2026.104513
Distance- and hierarchy-dependent functional dysconnectivity in schizophrenia and its association with cortical microstructure
Neuroimage Clin. 2026 Feb 4;49:103958. doi: 10.1016/j.nicl.2026.103958. Online ahead of print.
ABSTRACT
BACKGROUND: Schizophrenia is associated with widespread functional dysconnectivity, but the spatial scale and structural correlates of these alterations remain unclear. While relevant to local dysfunction, short-range connectivity is not well captured by standard approaches due to methodological constraints.
METHODS: We applied a vertex-wise, distance-dependent analysis of functional connectivity strength (FCS) to resting-state fMRI data from 86 schizophrenia patients and 99 healthy controls across two datasets. FCS was partitioned by geodesic distance on the cortical surface and analyzed by cortical hierarchy. We also assessed two proxies of intracortical microstructure: T1/T2 ratio and a novel signal-detection-based measure of individualized data-driven functional connectivity density (idFCD).
RESULTS: Schizophrenia patients exhibited reductions in short-range FCS within the dorsal primary somatosensory cortex. These functional alterations colocalized with abnormalities in both microstructural proxies and were not evident in global FCS analysis. In contrast, longer-range FCS was increased in transmodal regions, particularly the precuneus, without associated microstructural differences. Hierarchical analysis confirmed this dissociation, with structure-function disruption in primary networks and increased relative FCS in transmodal regions without microstructural association.
CONCLUSIONS: Our findings support two distinct patterns of cortical dysconnectivity in schizophrenia: short-range reductions in primary sensory areas that colocalize with microstructural abnormalities, and longer-range increases in transmodal regions that appear structurally decoupled at the local level. By integrating distance-dependent functional measures with independent proxies of intracortical microstructure, this study highlights the role of short-range connectivity disruptions in primary areas and provides a complementary framework to conventional approaches based on regional or global analyses and diffusion-weighted imaging.
PMID:41671792 | DOI:10.1016/j.nicl.2026.103958
Altered resting-state functional connectivity in delusional patients with schizophrenia or schizoaffective disorder: An fMRI study using threshold-free cluster-enhancement
Psychiatry Res Neuroimaging. 2026 Feb 3;358:112165. doi: 10.1016/j.pscychresns.2026.112165. Online ahead of print.
ABSTRACT
BACKGROUND: Delusions are a core symptom of schizophrenia and schizoaffective disorder (SCZ/SZA), yet their neural mechanisms remain incompletely understood. Contemporary models emphasize dysfunctional network-level interactions, particularly between subcortical and cortical regions.
OBJECTIVE: To characterize resting-state functional connectivity (rsFC) alterations specifically associated with prominent delusions in SCZ/SZA, with emphasis on cortico-subcortical and cerebellar networks.
METHODS: High-resolution ROI-to-ROI rsFC analyses were conducted in 20 SCZ/SZA patients with prominent delusions and 20 matched healthy controls. Functional connectivity was calculated across 164 regions using the Harvard-Oxford atlas. Statistical significance was assessed with threshold-free cluster enhancement (TFCE) and family-wise error (FWE) correction at p < 0.05.
RESULTS: Twenty significant connectivity clusters were identified, encompassing both hyper- and hypoconnectivity. Increased connectivity was observed between basal ganglia structures (putamen, pallidum) and cortical regions of the default mode network (DMN), frontal executive networks, and limbic areas, consistent with aberrant salience attribution and disrupted integration of internal and external signals.
CONCLUSION: Delusions in SCZ/SZA may stem from widespread dysconnectivity anchored in evolutionarily older subcortical and cerebellar regions, impairing sensorimotor, emotional, and cognitive integration. These findings support a network-based model of delusion formation and may inform potential targets for neuromodulatory intervention.
PMID:41671697 | DOI:10.1016/j.pscychresns.2026.112165
Spontaneous HRV fluctuations are linked to functional changes in resting state brain activation in younger and older adults
Auton Neurosci. 2026 Feb 5;264:103389. doi: 10.1016/j.autneu.2026.103389. Online ahead of print.
ABSTRACT
The vagus nerve connects the brain and the heart, allowing communication between the body and the mind. Studies have strengthened the meaning of the brain to control heart rate variability (HRV), however, brain research has largely overlooked the effects of age on the association between phasic changes in HRV and resting state functional brain connectivity. To close this gap, we studied a large open data set of 69 old and 134 young participants with two consecutive fMRI resting state scans in combination with the corresponding physiological HRV data assessed via photoplethysmography (PPG). We quantified spontaneous HRV changes from one resting state to the other and studied the unique information about the relationship between changes in functional coupling between brain areas and spontaneous HRV changes. Using a fc-MVPA, we identified functional brain coupling patterns associated with changes in HRV within brain networks, including the anterior cingulate cortex (ACC), the cerebellum, the brainstem, and the temporal lobe. These patterns were not significantly different between the two age groups - indicating age invariance of brain heart communication. Post hoc seed-to-voxel analyses indicated a stronger functional coupling of these identified clusters with brain regions such as the insula, the opercular cortex, the superior frontal gyrus, and the cerebellum when HRV increased. This pattern of findings is in accordance with prominent theories and provides further insights into the neural mechanisms underlying brain-heart communication.
PMID:41671693 | DOI:10.1016/j.autneu.2026.103389
Disrupted and reorganized connectivity of brain networks in multiple sclerosis: a systematic review and meta-analysis of resting-state functional MRI
J Neurol. 2026 Feb 11;273(2):139. doi: 10.1007/s00415-026-13665-9.
ABSTRACT
BACKGROUND: Abnormalities in large-scale brain functional networks are implicated in multiple sclerosis (MS) and linked to clinical impairments, but reported findings remain heterogeneous due to methodological and sample variations.
METHODS: Based on 25 resting-state functional magnetic resonance (rsfMRI) imaging studies (1,524 MS patients and 886 healthy controls (HCs)), in which the independent component analysis (ICA) method was used to evaluate the resting-state functional connectivity (rsFC) changes in default mode (DMN), sensorimotor (SMN), salience (SN), and visual (VN) networks, a meta-analysis was performed using the anisotropic effect size seed mapping (AES-SDM) software to quantify the differences between MS patients and HCs. The heterogeneity was assessed, and a meta-regression analysis was conducted on age, disease duration, Expanded Disability Status Scale scores, and T2-hyperintense lesion volume.
RESULTS: Compared with HCs, MS exhibited increased rsFC in left anterior cingulate/paracingulate gyri and right superior frontal gyrus (DMN), bilateral precentral gyrus and right postcentral gyrus (SMN), right angular gyrus (SN), whereas hypoconnectivity was observed in left posterior cingulate gyrus (DMN), right supplementary motor region and left precentral gyrus (SMN), right insula (SN), and left superior parietal gyrus (VN). The Meta-regression analysis revealed no significant correlation between these altered rsFC and clinical variables.
DATA CONCLUSIONS: This study demonstrates widespread and complex rsFC abnormalities in several neural networks in MS, particularly within core regions of the DMN, SMN, VN, and SN. Together with a descriptive synthesis of additional RSNs, these rsFC disruptions and reorganizations may represent intrinsic neuropathological alterations in MS, which further elucidate the pathophysiological mechanisms of functional abnormalities in MS at a large-scale level.
PMID:41670734 | DOI:10.1007/s00415-026-13665-9
Dynamic network reconfiguration in hepatitis B cirrhosis secondary to mild hepatic encephalopathy: a multilayer network analysis
Quant Imaging Med Surg. 2026 Feb 1;16(2):163. doi: 10.21037/qims-24-2442. Epub 2026 Jan 14.
ABSTRACT
BACKGROUND: Static functional networks of the brain are disrupted in minimal hepatic encephalopathy (MHE), but their dynamic alterations are unknown. This observational study utilized multilayer network analysis to investigate dynamic network characteristics in hepatitis B cirrhosis (HBC) with or without MHE and assess their association with neurocognitive function (registry: https://ctms.xyeyy.com/iit/project/index; trial registration number: LYF20240134; date: 2024-07-31).
METHODS: A total of 33 HBC patients [15 non-MHE (NMHE; HBC patients without MHE) and 18 MHE individuals], as well as 36 matched healthy controls (HCs), underwent neurocognitive assessments, resting-state functional magnetic resonance imaging (rs-fMRI), and clinical examinations. Dynamic network variations were quantified using network switching rates, and their relationships with clinical and neurocognitive parameters were evaluated.
RESULTS: Both HBC patients with and without MHE status exhibited a range of altered network switching rates compared to HCs. Specifically, differences were observed in subnetworks including somatomotor network (SMN), dorsal attention network (DAN), ventral attention network (VAN), frontoparietal network (FPN), and subcortical network (SUB), as well as in nodal regions such as the right precentral gyrus (rPrG), left fusiform gyrus (lFuG), left inferior parietal lobule (lIPL), and right hippocampus (rHipp). Furthermore, altered global level and lFuG switching rates positively correlated with Psychometric Hepatic Encephalopathy Score (PHES) (r=0.341, 0.339; P=0.004, 0.004, respectively, Bonferroni corrected).
CONCLUSIONS: This study firstly revealed that HBC patients exhibited imbalanced functional dynamics in subnetworks and nodes, suggesting a potential mechanism underlying cerebral dysfunction in MHE.
PMID:41669485 | PMC:PMC12883493 | DOI:10.21037/qims-24-2442
Vestibular nucleus-thalamus-cortex pathway abnormalities persist in patients with chronic unilateral vestibulopathy after the establishment of vestibular static compensation
Quant Imaging Med Surg. 2026 Feb 1;16(2):153. doi: 10.21037/qims-2025-177. Epub 2026 Jan 13.
ABSTRACT
BACKGROUND: After vestibular impairment, the body undergoes static and dynamic compensation. Static compensation is characterized by the resolution of spontaneous nystagmus, indicating rebalanced bilateral vestibular nuclei activity. It remains unclear whether ascending vestibular projections remain abnormal thereafter. This study investigated abnormal functional activity along vestibular nucleus-thalamus-cortex projection pathways in chronic unilateral vestibulopathy (CUVP) after static compensation using degree centrality (DC) and functional connectivity (FC) analyses.
METHODS: In total, 25 CUVP patients and 25 age- and sex-matched healthy controls underwent resting-state functional magnetic resonance imaging (fMRI). The DC analysis identified abnormal functional activity in vestibular nucleus-thalamus-cortex pathways, particularly in the subcortical structures. The seed-based FC analyses used eight seeds (the bilateral vestibular nuclei, and the bilateral pulvinar, mediodorsal, and ventrolateral ventral thalamic regions) with 10,000 non-parametric permutations and a cluster-level family-wise error rate (FWER)-corrected threshold of P<0.05. The region-of-interest (ROI)-based FC analyses examined connections among the vestibular nucleus, thalamic subregions (the pulvinar and ventrolateral ventral thalamus), and multisensory vestibular/sensorimotor/visual cortices with a false discovery rate (FDR)-corrected threshold of P<0.05 to confirm the pathway abnormalities. A regression analysis assessed the relationships between the altered brain metrics and Dizziness Handicap Inventory (DHI) scores.
RESULTS: Compared with the healthy controls, the CUVP patients showed reduced DC in the bilateral thalamus (ventrolateral ventral thalamus, and pulvinar), cerebellum, precuneus, postcentral gyrus, and premotor areas (all FDR-corrected P<0.05). Using the vestibular nucleus, pulvinar, and ventrolateral ventral thalamus as the seed regions, similar bilateral patterns of FC change were observed, with notably reduced FC between the pulvinar and visual cortex, as well as between the ventrolateral ventral thalamus and sensorimotor cortex (all FWER-corrected P<0.05). The ROI-based FC analyses confirmed abnormalities along the vestibular nucleus-ventrolateral ventral thalamus/pulvinar-multisensory vestibular/sensorimotor/visual cortices pathways (all FDR-corrected P<0.05). The regression analysis revealed negative associations between thalamic DC/FC changes and DHI scores (all FDR-corrected P<0.05).
CONCLUSIONS: Patients with CUVP exhibit persistent abnormalities in the vestibular nucleus-thalamus-cortex pathways even after the establishment of static compensation. The ventrolateral ventral thalamus and pulvinar may serve as key nodes in these abnormalities.
PMID:41669411 | PMC:PMC12883438 | DOI:10.21037/qims-2025-177
Excluding spontaneous thought periods enhances functional connectivity test-retest reliability and machine learning performance in fMRI
Front Neurosci. 2026 Jan 26;19:1730402. doi: 10.3389/fnins.2025.1730402. eCollection 2025.
ABSTRACT
INTRODUCTION: Resting-state functional magnetic resonance imaging (rs-fMRI) is a widely used non-invasive technique for investigating brain function and identifying potential disease biomarkers. Compared with task-based fMRI, rs-fMRI is easier to acquire because it does not require explicit task paradigms. However, functional connectivity measures derived from rs-fMRI often exhibit poor reliability, which substantially limits their clinical applicability.
METHODS: To address this limitation, we propose a novel method termed time-enhanced functional connectivity, which improves reliability by identifying and removing poor-quality time points from rs-fMRI time series. This approach aims to enhance the quality of functional connectivity estimation without extending scan duration or relying on dataset-specific constraints.
RESULTS: Experimental results demonstrate that the proposed method significantly improves performance in downstream machine learning tasks, such as sex classification. In addition, time-enhanced functional connectivity yields higher test-retest reliability and reveals more pronounced statistical differences between groups compared with conventional functional connectivity measures.
DISCUSSION: These findings suggest that selectively removing low-quality time points provides a practical and effective strategy for improving the reliability and sensitivity of functional connectivity measurements in rs-fMRI, thereby enhancing their potential utility in both neuroscience research and clinical applications.
PMID:41668725 | PMC:PMC12883793 | DOI:10.3389/fnins.2025.1730402
Altered functional connectivity density in the prefrontal-limbic-visual networks of vestibular migraine
Sci Rep. 2026 Feb 10. doi: 10.1038/s41598-026-38116-3. Online ahead of print.
ABSTRACT
This study aimed to explore abnormal patterns of functional connectivity density (FCD) and functional connectivity (FC) in patients with vestibular migraine (VM) and their associations with clinical symptoms. Resting-state functional magnetic resonance imaging (rs-fMRI) data from 49 VM patients and 61 healthy controls (HCs) were analyzed using Global FCD (GFCD), long-range FCD (LRFCD), and seed-based FC. Compared with HCs, VM patients demonstrated decreased GFCD and LRFCD in the bilateral medial prefrontal cortex (mPFC), along with increased GFCD in the right lingual gyrus (LING), right middle occipital cortex (MOC), left precuneus (preCUN), and elevated LRFCD in the middle cingulate cortex (MCC) and bilateral MOC. Seed-based FC analysis revealed significantly reduced connectivity between the mPFC and multiple regions, including the right cuneus/precuneus (CUN/preCUN), bilateral posterior cingulate cortex (PCC), bilateral hippocampus/parahippocampus (HIPP/ParaHIPP), and left calcarine cortex (CAL) in VM patients. Correlation analysis identified a positive association between GFCD in the left preCUN and Dizziness Handicap Inventory (DHI) scores (r = 0.370, p = 0.011). These findings highlight disrupted prefrontal-limbic-visual network integration in VM, with precuneus dysfunction potentially linked to dizziness severity. This study provides novel insights into the neural mechanisms underlying VM, highlighting the role of altered functional integration in symptom manifestation.
PMID:41667547 | DOI:10.1038/s41598-026-38116-3
Randomized controlled trial of resistance exercise and brain aging clocks
Geroscience. 2026 Feb 10. doi: 10.1007/s11357-026-02141-x. Online ahead of print.
ABSTRACT
Exercise improves cognition, mental wellbeing, and protects against neurodegeneration. However, most prior neuroscience studies have focused on localized brain changes without quantifying their impact on brain ageing. To quantify the effect of resistance training on brain health using longitudinal assessments. Using resting-state functional magnetic resonance imaging (rs-fMRI) data from 2,433 healthy adults, we trained models to predict brain age and applied them to 309 participants from the Live Active Successful Aging (LISA) randomized trial. Participants in this trial were assigned to one of three groups: heavy-resistance training, moderate-intensity training, or a non-exercise control group. They underwent repeated rs-fMRI and physical fitness assessments at baseline, with follow-up assessments at 1 and 2 years. First, we examined changes in local connectivity between groups. Second, we assessed the impact of resistance training on brain ageing using brain clock models trained on the independent dataset of 2,433 adults. Local analyses revealed increased prefrontal functional connectivity following heavy training, while moderate- and heavy-resistance training significantly reduced brain age (-1.4 to -2.3 years, pFDR < 0.05). These effects emerged at the whole-brain level, rather than within isolated networks such as the default mode, motor, or cerebellar systems. These findings suggest a hierarchical organization of brain aging, driven by distributed network-level changes and expressed through focal regional patterns. Resistance exercise training decelerates brain ageing, as indexed by brain clocks, reinforcing its role as a preventive strategy for brain health.
PMID:41665740 | DOI:10.1007/s11357-026-02141-x
Global brain activity links subcortical degeneration to cortical tau progressively across Braak regions over early Alzheimer's disease stages
bioRxiv [Preprint]. 2026 Jan 26:2026.01.23.701360. doi: 10.64898/2026.01.23.701360.
ABSTRACT
Alzheimer's disease (AD) is characterized by early tau pathology in subcortical neuromodulatory nuclei, followed by progressive cortical tau accumulation; however, the mechanisms linking subcortical dysfunction to cortical tau pathology remain unclear. Using multimodal neuroimaging data from the ADNI cohort, we examined how infra-slow (< 0.1 Hz) global brain (i.e., gBOLD) activity is related to the volume of the nucleus basalis of Meynert (NbM) and cortical tau accumulations in the early stages of AD. NbM degeneration was associated with reduced gBOLD activity and spatially co-localized tau accumulation, appearing in early Braak regions during the preclinical stage, i.e., cognitively unimpaired participants with abnormal CSF markers, and extending to more advanced Braak areas during the prodromal stage, i.e., mild cognitive impairment (MCI) subjects. Our findings suggest that infra-slow gBOLD activity serves as a functional neural mediator linking subcortical degeneration to cortical tau pathology, highlighting a potential functional pathway linking subcortical and cortical pathology in early AD.
PMID:41659428 | PMC:PMC12873826 | DOI:10.64898/2026.01.23.701360
Interactions between sensory-biased and supramodal working memory networks in the human cerebral cortex
Commun Biol. 2026 Feb 9. doi: 10.1038/s42003-026-09688-7. Online ahead of print.
ABSTRACT
Human working memory is supported by a broadly distributed set of brain networks. Content-specific networks communicate with a domain-general, supramodal network that is recruited regardless of the type of content. Here, we contrasted visual and auditory working memory tasks to examine interactions between the supramodal network and two content-specific networks. Functional connectivity among visual-biased, auditory-biased, and supramodal working memory networks was assayed by collecting task and resting-state fMRI data from 24 human participants (age 18-43; 11 men and 13 women). At rest, as found previously, the supramodal network exhibited stronger functional connectivity with the visual-biased network than with the auditory-biased network. This asymmetry raises questions about how networks communicate to support robust performance across modalities. However, during auditory task performance, dynamic changes increased auditory network connectivity with supramodal and visual-biased frontal regions, while decreasing connectivity from posterior visual areas to supramodal and frontal visual regions. In contrast, the visual task produced weak changes. Across individuals, auditory working memory precision correlated with the strength of auditory network connectivity changes, while no such brain-behavior link was observed for visual working memory. These results demonstrate an asymmetry in working memory network organization and reveal that dynamic reorganization accompanies performance of working memory tasks.
PMID:41663792 | DOI:10.1038/s42003-026-09688-7