Resting-state Scans Research Articles

Integrating fMRI spatial network dynamics and EEG spectral power: insights into resting state connectivity

IntroductionThe Integration of functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) has allowed for a novel exploration of the brain’s spatial–temporal resolution. While functional brain networks show variations in both spatial and temporal dimensions, most studies focus on fixed spatial networks that change together over time.MethodsIn this study, for the first time, we link spatially dynamic brain networks with EEG spectral properties recorded simultaneously, which allows us to concurrently capture high spatial and temporal resolutions offered by these complementary imaging modalities. We estimated time-resolved brain networks using sliding window-based spatially constrained independent component analysis (scICA), producing resting brain networks that evolved over time at the voxel level. Next, we assessed their coupling with four time-varying EEG spectral power (delta, theta, alpha, and beta).ResultsOur analysis demonstrated how the networks’ volumes and their voxel-level activities vary over time and revealed significant correlations with time-varying EEG spectral power. For instance, we found a strong association between increasing volume of the primary visual network and alpha band power, consistent with our hypothesis for eyes open resting state scan. Similarly, the alpha, theta, and delta power of the Pz electrode were localized to voxel-level activities of primary visual, cerebellum, and temporal networks, respectively. We also identified a strong correlation between the primary motor network and alpha (mu rhythm) and beta activity. This is consistent with motor tasks during rest, though this remains to be tested directly.DiscussionThese association between space and frequency observed during rest offer insights into the brain’s spatial–temporal characteristics and enhance our understanding of both spatially varying fMRI networks and EEG band power.

Criticality is Associated with Future Psychotherapy Response in Patients with Post-Traumatic Stress Disorder—A Pilot Study

Background Trauma-focused psychotherapy is treatment of choice for post-traumatic stress disorder (PTSD). However, about half of patients do not respond. Recently, there is increased interest in brain criticality, which assesses the phase transition between order and disorder in brain activity. Operating close to this borderline is theorized to facilitate optimal information processing. We studied if brain criticality is related to future response to treatment, hypothesizing that treatment responders’ brains function closer to criticality. Methods Functional magnetic resonance imaging resting-state scans were acquired from 46 male veterans with PTSD around the start of treatment. Psychotherapy consisted of trauma-focused cognitive behavioral therapy, eye movement desensitization and reprocessing, or a combination thereof. Treatment response was assessed using the Clinician-Administered PTSD Scale, and criticality was assessed using an Ising temperature approach for seven canonical brain networks (ie, the visual, somatomotor, dorsal attention, ventral attention, limbic, frontoparietal and default mode networks) to measure distance to criticality. Results The brains of prospective treatment responders were closer to criticality than nonresponders (P = 0.017), while no significant interaction effect between group and brain network was observed (P = 0.486). In addition, average criticality across networks correlated with future treatment response (P = 0.028). Conclusion These results show that the brains of prospective PTSD psychotherapy treatment responders operate closer to criticality than nonresponders, and this occurs across the entire brain instead of in separate canonical brain networks. These results suggest that effective psychotherapy is mediated by brains operating closer to criticality.

Transcranial Direct Current Stimulation Over Bilateral Temporal Lobes Modulates Hippocampal-Occipital Functional Connectivity and Visual Short-Term Memory Precision.

Although the medial temporal lobe (MTL) is traditionally considered a region dedicated to long-term memory, recent neuroimaging and intracranial recording evidence suggests that the MTL also contributes to certain aspects of visual short-term memory (VSTM), such as the quality or precision of retained VSTM content. This study aims to further investigate the MTL's role in VSTM precision through the application of transcranial direct current stimulation (tDCS) and functional magnetic resonance imaging (fMRI). Participants underwent 1.5 mA offline tDCS over bilateral temporal lobes using left cathodal and right anodal electrodes, administered for either 20 min (active) or 0.5 min within a 20-min window (sham), in a counterbalanced design. As the electrical current passes through midbrain structures with this bilateral stimulation montage, prior behavioral and modeling evidence suggests that this tDCS protocol can modulate MTL functions. To confirm this and examine its impacts on VSTM, participants completed a VSTM color recall task immediately following tDCS, while undergoing a 20-min fMRI scan and a subsequent 7.5-min resting-state scan, during which they focused on a fixation cross. Behavioral results indicated that this tDCS protocol decreased VSTM precision without significantly affecting overall recall success. Furthermore, psychophysiological interaction analysis revealed that tDCS over the temporal lobe modulated hippocampal-occipital functional connectivity during the VSTM task, despite no main effect on fMRI BOLD activity. Notably, this modulation was also observed during resting-state fMRI 15-20 min post-tDCS, with the magnitude of the effect correlating with participants' behavioral changes in VSTM precision across active and control conditions. Combined, these findings suggest that tDCS over the temporal lobe can modulate the intrinsic functional connectivity between the MTL and visual sensory areas, thereby affecting VSTM precision.

Functional Connectivity of the Affective Blindsight Pathway in Atypical Alzheimer’s Disease

AbstractBackgroundAffective cognition and emotion processing is impaired in amnestic Alzheimer’s disease (AD), although less is known about atypical (AT) variants such as logopenic variant primary progressive aphasia (lvPPA) and posterior cortical atrophy (PCA). The affective blindsight pathway bypasses V1 via the superior colliculus‐pulvinar route to activate the amygdala in cases of occipital lesioning and may explain maintenance of emotion identification and visual information processing in non‐amnestic AD despite atrophy in visuospatial regions. We sought to characterize functional connectivity from key regions along the affective blindsight pathway in a clinically heterogeneous AD cohort.MethodWe collected structural, resting‐state, and task functional MRI scans where participants viewed affective face and neutral scene images, and neuropsychological data in individuals with clinically heterogeneous AD (8 lvPPA, 9 PCA) and age‐matched healthy controls (24 HC). We assessed connectivity from 4mm radius seeds located along the affective blindsight pathway (superior colliculus, medial pulvinar, and amygdala) using CONN toolbox. Two‐sample t‐tests were used to compute group‐level differences (AT > HC; p < 0.05/0.05), using w‐scores to correct for atrophy.ResultAs expected, AT participants performed significantly worse on visuospatial tasks outside the scanner (WAIS‐III Blocks Design, Benson Complex Figure Copy immediate recall; p < 0.01). During resting state scans, the AT group had relatively lower connectivity to visuospatial regions including the lateral occipital cortex, angular gyrus, and precuneus from the superior colliculus and medial pulvinar seeds. During the scenes/faces task, they displayed relatively higher connectivity to those same visuospatial regions. From the amygdala seed, the AT group had higher connectivity to area V1 during the resting state scan and lower connectivity to frontal lobe regions during scenes/faces.ConclusionWe explored functional connectivity of the affective blindsight pathway in a clinically heterogeneous AD cohort. Connectivity was relatively higher in the AT group from the superior colliculus, medial pulvinar, and amygdala to occipital lobe regions commonly atrophied in PCA and lvPPA, suggesting a function of this pathway may be to compensate for disease‐related atrophy. While preliminary, these findings hint that the blindsight pathway may serve a compensatory function in atypical AD.

Resting-state fNIRS reveals changes in prefrontal cortex functional connectivity during TENS in patients with chronic pain

Transcutaneous electrical nerve stimulation (TENS) has been used to treat chronic pain. However, the potential efficacy and mechanism of the effect of applying TENS for a short time in chronic pain patients remains unclear. To identify the effect of short-term TENS on chronic pain patients and to clarify the mechanism of the effect, we investigated abnormalities of functional connectivity (FC) within the prefrontal cortex (PFC) using resting-state functional near-infrared spectroscopy (rs-fNIRS). Fifteen patients (56.8 ± 17.4 years, nine females) with chronic pain participated in this rs-fNIRS study. The fNIRS scans included two parts: a 5-minute resting-state scan followed by a 5-minute scan during TENS (150 Hz) application. The pain intensity was measured using a Visual Analog Scale (VAS) and Pittsburgh Sleep Quality Index (PSQI). The spontaneous brain activity of the PFC and resting-state functional connectivity (rsFC) in the PFC were examined during TENS and compared to before TENS. The results showed that Pain intensity significantly decreased after TENS (p < 0.001). During TENS, fALFF values were significantly lower in BA46 (**p = 0.0025) and BA45 (**p = 0.0056). rsFC strength increased during TENS compared to before, with significant group-level increases in BA10, BA9, BA46, and BA44/45 (p < 0.05). Notably, the variation between BA10 and BA44/45 was highly significant (***p < 0.001). These findings suggest that FC between BA10 and BA44/45 was associated with analgesia of TENS in patients with chronic pain, indicating the potential role of FC as a novel objective parameter to predict the outcome of clinical use of TENS for pain relief in chronic pain patients.

Hemodynamic cortical ripples through cyclicity analysis.

A fine-grained understanding of dynamics in cortical networks is crucial to unpacking brain function. Resting-state functional magnetic resonance imaging (fMRI) gives rise to time series recordings of the activity of different brain regions, which are aperiodic and lack a base frequency. Cyclicity analysis, a novel technique robust under time reparametrizations, is effective in recovering the temporal ordering of such time series, collectively considered components of a multidimensional trajectory. Here, we extend this analytical method for characterizing the dynamic interaction between distant brain regions and apply it to the data from the Human Connectome Project. Our analysis detected cortical traveling waves of activity propagating along a spatial axis, resembling cortical hierarchical organization with consistent lead-lag relationships between specific brain regions in resting-state scans. In fMRI scans involving tasks, we observed short bursts of task-modulated strong temporal ordering that dominate overall lead-lag relationships between pairs of regions in the brain that align temporally with stimuli from the tasks. Our results suggest a possible role played by waves of excitation sweeping through brain regions that underlie emergent cognitive functions.

Визначення предикторів діагнозу пацієнтів з ПТСР на основі параметрів одновимірних моделей першого порядку BOLD-сигналів структур мозку та МГУА

Introduction. The use of functional magnetic resonance imaging (fMRI) allows for the assessment of processes occurring in the brain. By analyzing the examination results, it is possible to establish the parameters of connections between brain structures, and changes in the values of these parameters can be used as diagnostic conclusion predictors for PTSD-patients. Purpose. To identify predictors for the classification of the PTSD diagnosis using the connectivity parameters of BOLD signals from brain structures. Methods. The technology for identifying predictors of PTSD diagnosis is based on a) the formation of connectivity parameters of BOLD signals from brain structures obtained during resting-state scanning, b) the use of classifier-oriented selection based on inter-class variance and mRMR criteria to select informative features, and c) the classification of PTSD diagnosis using a logistic regression algorithm optimized by the Group Method of Data Handling. Results. The technology proposed in this work enabled the selection of informative features and the identification of their predictive forms, resulting in the formation of classifiers for the diagnosis of PTSD with high accuracy, sensitivity, and specificity. Conclusion. A technology for the formation, selection, and use of connectivity parameters of BOLD signals from brain structures has been proposed for differentiating healthy individuals from those who suffer with PTSD. A list of the most informative features of PTSD and their predictive forms in the form of generalized variables has been obtained, which can be used for diagnostic conclusions. The results obtained indicate the presence of a specific type of connection between the brain areas identified in the study based on levels of excitation (parameters а0 of the models) and the alteration of these levels in the context of PTSD.

Precision mapping of the default network reveals common and distinct (inter) activity for autobiographical memory and theory of mind.

The default network is widely implicated as a common neural substrate for self-generated thought, such as remembering one's past (autobiographical memory) and imagining the thoughts and feelings of others (theory of mind). Findings that the default network comprises subnetworks of regions, some commonly and some distinctly involved across processes, suggest that one's own experiences inform their understanding of others. With the advent of precision functional MRI (fMRI) methods, however, it is unclear if this shared substrate is observed instead due to traditional group analysis methods. We investigated this possibility using a novel combination of methodological strategies. Twenty-three participants underwent multi-echo resting-state and task fMRI. We used their resting-state scans to conduct cortical parcellation sensitive to individual variation while preserving our ability to conduct group analysis. Using multivariate analyses, we assessed the functional activation and connectivity profiles of default network regions while participants engaged in autobiographical memory, theory of mind, or a sensorimotor control condition. Across the default network, we observed stronger activity associated with both autobiographical memory and theory of mind compared to the control condition. Nonetheless, we also observed that some regions showed preferential activity to either experimental condition, in line with past work. The connectivity results similarly indicated shared and distinct functional profiles. Our results support that autobiographical memory and theory of mind, two theoretically important and widely studied domains of social cognition, evoke common and distinct aspects of the default network even when ensuring high fidelity to individual-specific characteristics.NEW & NOTEWORTHY We used cutting-edge precision functional MRI (fMRI) methods such as multi-echo fMRI acquisition and denoising, a robust experimental paradigm, and individualized cortical parcellation across 23 participants to provide evidence that remembering one's past experiences and imagining the thoughts and feelings of others share a common neural substrate. Evidence from activation and connectivity analyses indicate overlapping and distinct functional profiles of these widely studied episodic and social processes.

Functional dissociation of the language network and other cognition in early childhood.

Is language distinct from other cognition during development? Does neural machinery for language emerge from general-purpose neural mechanisms, becoming tuned for language after years of experience and maturation? Answering these questions will shed light on the origins of domain-specificity in the brain. We address these questions using precision fMRI, scanning young children (35 months to 9 years of age) on an auditory language localizer, spatial working memory localizer (engaging the domain-general multiple demand [MD] network), and a resting-state scan. We create subject-specific functional regions of interest for each network and examine their selectivity, specificity, and functional connectivity. We find young children show domain-specific, left-lateralized language activation, and that the language network is not responsive to domain-general cognitive load. Additionally, the cortically adjacent MD network is selective to cognitive load, but not to language. These networks show higher within versus between-network functional connectivity. This connectivity is stable across ages (examined cross-sectionally and longitudinally), whereas language responses increase with age and across time within subject, reflecting a domain-specific developmental change. Overall, we provide evidence for a double dissociation of the language and MD network throughout development, in both their function and connectivity. These findings suggest that domain-specificity, even for uniquely human cognition like language, develops early and distinctly from mechanisms that presumably support other human cognition.

Functional connectivity changes in meditators and novices during yoga nidra practice

Yoga nidra (YN) practice aims to induce a deeply relaxed state akin to sleep while maintaining heightened awareness. Despite the growing interest in its clinical applications, a comprehensive understanding of the underlying neural correlates of the practice of YN remains largely unexplored. In this fMRI investigation, we aim to discover the differences between wakeful resting states and states attained during YN practice. The study included individuals experienced in meditation and/or yogic practices, referred to as ‘meditators’ (n = 30), and novice controls (n = 31). The GLM analysis, based on audio instructions, demonstrated activation related to auditory cues without concurrent default mode network (DMN) deactivation. DMN seed based functional connectivity (FC) analysis revealed significant reductions in connectivity among meditators during YN as compared to controls. We did not find differences between the two groups during the pre and post resting state scans. Moreover, when DMN-FC was compared between the YN state and resting state, meditators showed distinct decoupling, whereas controls showed increased DMN-FC. Finally, participants exhibit a remarkable correlation between reduced DMN connectivity during YN and self-reported hours of cumulative meditation and yoga practice. Together, these results suggest a unique neural modulation of the DMN in meditators during YN which results in being restful yet aware, aligned with their subjective experience of the practice. The study deepens our understanding of the neural mechanisms of YN, revealing distinct DMN connectivity decoupling in meditators and its relationship with meditation and yoga experience. These findings have interdisciplinary implications for neuroscience, psychology, and yogic disciplines.

Predicting high-level visual areas in the absence of task fMRI.

The ventral visual stream is organized into units, or functional regions of interest (fROIs), specialized for processing high-level visual categories. Task-based fMRI scans ("localizers") are typically used to identify each individual's nuanced set of fROIs. The unique landscape of an individual's functional activation may rely in large part on their specialized connectivity patterns; recent studies corroborate this by showing that connectivity can predict individual differences in neural responses. We focus on the ventral visual stream and ask: how well can an individual's resting state functional connectivity localize their fROIs for face, body, scene, and object perception? And are the neural processors for any particular visual category better predicted by connectivity than others, suggesting a tighter mechanistic relationship between connectivity and function? We found, among 18 fROIs predicted from connectivity for each subject, all but one were selective for their preferred visual category. Defining an individual's fROIs based on their connectivity patterns yielded regions that were more selective than regions identified from previous studies or atlases in nearly all cases. Overall, we found that in the absence of a domain-specific localizer task, a 10-min resting state scan can be reliably used for defining these fROIs.

Altered functional-structural coupling may predict Parkinson's patient's depression.

We aimed to elucidate the neurobiological basis of depression in Parkinson's disease and identify potential imaging markers for depression in patients with Parkinson's disease. We recruited 43 normal controls (NC), 46 depressed Parkinson's disease patients (DPD) and 56 non-depressed Parkinson's disease (NDPD). All participants underwent routine T2-weighted, T2Flair, and resting-state scans on the same 3.0T magnetic resonance imaging (MRI) scanner at our hospital. Pre-processing includes calculating surface-based Regional Homogeneity (2DReHo) and cortical thickness. Then we defined the correlation coefficient between 2DReHo and cortical thickness as the functional-structural coupling index. Between-group comparisons were conducted on the Fisher's Z-transformed correlation coefficients. To identify specific regions of decoupling, the 2DReHo for each participant were divided by cortical thickness at each vertex, followed by threshold-free cluster enhancement (TFCE) multiple comparison correction. Binary logistic regression analysis was performed with DPD as the dependent variable, and significantly altered indicators as the independent variables. Receiver operating characteristic curves were constructed to compare the diagnostic performance of individual predictors and combinations using R and MedCalc software. DPD patients exhibited a significantly lower whole-brain functional-structural coupling index than NDPD patients and NC. Abnormal functional-structural coupling was primarily observed in the left inferior parietal lobule and right primary and early visual cortices in DPD patients. Receiver operating characteristic analysis revealed that the combination of cortical functional-structural coupling, surface-based ReHo, and thickness had the best diagnostic performance, achieving a sensitivity of 65% and specificity of 77.7%. This is the first study to explore the relationship between functional and structural changes in DPD patients and evaluate the diagnostic performance of these altered correlations to predict depression in Parkinson's disease patients. We posit that these changes in functional-structural relationships may serve as imaging biomarkers for depression in Parkinson's disease patients, potentially aiding in the classification and diagnosis of Parkinson's disease. Additionally, our findings provide functional and structural imaging evidence for exploring the neurobiological basis of depression in Parkinson's disease.

Correlations of altered functional connectivity in resting-state fMRI and symptom severity in tic disorders

IntroductionVocal and motor tics are characteristic for Tic disorders (TD) and Tourette’s syndrome (APA 2022) . Because of the pathophysiology of the disorders not being fully understood and the presence of the externally measurable symptoms; great attention has been paid to the cortico-striatal regions of patients with TD . In addition to the alterations in motor symptoms patients can experience a premonitory urge (PU) which can be felt before a tic (Reese et al. Behav. Ther. 2014; 45 177–186) . Previous studies found an impact of these urges on sensory perception, attention and social cognition as well as an involvement of the brain regions insula, anterior cingulate cortex (ACC) and the temporoparietal junction (TPJ) (Seeley J. Neurosci. 2019; 39 9878–9882, Kucyi et al. J. Neurophysiol. 2012; 108 3382–3392, Uddin et al. Brain Topogr. 2019; 32 926–942) . These findings lead to the idea of altered functional connectivity of the salience network (SN) in patients with TD.ObjectivesThis study aims to investigate the connectivity changes of the SN in patients with TD. We examined functional resting-state scans of patients with TD and searched for possible correlations between the tic and PU severity and the connectivity of the SN.Methods 21 Patients (mean age: 30.9 years ± 10.0 [range = 19–57], 6 females) diagnosed with TD, and 20 healthy controls (mean age: 29.7 years ± 8.9 [range = 18–50], 5 females) underwent a resting-state fMRI scan. Functional and anatomical images were conducted on a 3T Siemens Prisma fit MRI scanner. PU and tic severity were measured by the Premonitory Urges for Tics Scale (PUTS) and the Yale Global Tic Severity Scale (YGTSS). The connectivity analysis of the resting-state scans was done using the CONN toolbox v21.a. After pre-processing and de-noising steps, a whole-brain seed-based connectivity analysis was carried out with the seeds being the major cortical nods of the SN. For the correlation analysis a linear regression of the YGTSS score/PUTS score and the brain connectivity of the seed regions was conducted.ResultsThe PUTS score was 25.3±5.4 (range 10-33) and the YGTSS total tic score was 23.1±7.9 (range 10-38) for the patients. The connectivity analysis revealed a significant difference in connectivity between the groups for the ACC, the right insula and the TPJ. A negative correlation between the YGTSS scores and the connectivity of the left insula and the right superior frontal gyrus (SFG) was shown in the correlation analysis. No significant correlation was found for the PUTS scores in the investigated seed regions.ConclusionsThe right SFG mediates motor urgency and inhibitory control. Since we found a negative correlation between the insula and the right SFG regarding to higher YGTSS scores of the patients, our results might shed some light on the pathophysiology regarding lower inhibitory control in patients which experience higher tic severity.Disclosure of InterestNone Declared

Searching Reproducible Brain Features using NeuroMark: Templates for Different Age Populations and Imaging Modalities

A primary challenge to the data-driven analysis is the balance between poor generalizability of population-based research and characterizing more subject-, study- and population-specific variability. We previously introduced a fully automated spatially constrained independent component analysis (ICA) framework called NeuroMark and its functional MRI (fMRI) template. NeuroMark has been successfully applied in numerous studies, identifying brain markers reproducible across datasets and disorders. The first NeuroMark template was constructed based on young adult cohorts. We recently expanded on this initiative by creating a standardized normative multi-spatial-scale functional template using over 100,000 subjects, aiming to improve generalizability and comparability across studies involving diverse cohorts. While a unified template across the lifespan is desirable, a comprehensive investigation of the similarities and differences between components from different age populations might help systematically transform our understanding of the human brain by revealing the most well-replicated and variable network features throughout the lifespan. In this work, we introduced two significant expansions of NeuroMark templates first by generating replicable fMRI templates for infants, adolescents, and aging cohorts, and second by incorporating structural MRI (sMRI) and diffusion MRI (dMRI) modalities. Specifically, we built spatiotemporal fMRI templates based on 6,000 resting-state scans from four datasets. This is the first attempt to create robust ICA templates covering dynamic brain development across the lifespan. For the sMRI and dMRI data, we used two large publicly available datasets including more than 30,000 scans to build reliable templates. We employed a spatial similarity analysis to identify replicable templates and investigate the degree to which unique and similar patterns are reflective in different age populations. Our results suggest remarkably high similarity of the resulting adapted components, even across extreme age differences. With the new templates, the NeuroMark framework allows us to perform age-specific adaptations and to capture features adaptable to each modality, therefore facilitating biomarker identification across brain disorders. In sum, the present work demonstrates the generalizability of NeuroMark templates and suggests the potential of new templates to boost accuracy in mental health research and advance our understanding of lifespan and cross-modal alterations.

Transcranial focused ultrasound of the amygdala modulates fear network activation and connectivity

BackgroundCurrent noninvasive brain stimulation methods are incapable of directly modulating subcortical brain regions critically involved in psychiatric disorders. Transcranial Focused Ultrasound (tFUS) is a newer form of noninvasive stimulation that could modulate the amygdala, a subcortical region implicated in fear. ObjectiveWe investigated the effects of active and sham tFUS of the amygdala on fear circuit activation, skin conductance responses (SCR), and self-reported anxiety during a fear-inducing task. We also investigated amygdala tFUS’ effects on amygdala-fear circuit resting-state functional connectivity. MethodsThirty healthy individuals were randomized in this double-blinded study to active or sham tFUS of the left amygdala. We collected fMRI scans, SCR, and self-reported anxiety during a fear-inducing task (participants viewed red or green circles which indicated the risk of receiving an aversive stimulus), as well as resting-state scans, before and after tFUS. ResultsCompared to sham tFUS, active tFUS was associated with decreased (pre to post tFUS) blood-oxygen-level-dependent fMRI activation in the amygdala (F(1,25) = 4.86, p = 0.04, η2 = 0.16) during the fear task, and lower hippocampal (F(1,27) = 4.41, p = 0.05, η2 = 0.14), and dorsal anterior cingulate cortex (F(1,27) = 6.26, p = 0.02; η2 = 0.19) activation during the post tFUS fear task. The decrease in amygdala activation was correlated with decreased subjective anxiety (r = 0.62, p = 0.03). There was no group effect in SCR changes from pre to post tFUS (F(1,23) = 0.85, p = 0.37). The active tFUS group also showed decreased amygdala-insula (F(1,28) = 4.98, p = 0.03) and amygdala-hippocampal (F(1,28) = 7.14, p = 0.01) rsFC, and increased amygdala-ventromedial prefrontal cortex (F(1,28) = 3.52, p = 0.05) resting-state functional connectivity. ConclusionstFUS can change functional connectivity and brain region activation associated with decreased anxiety. Future studies should investigate tFUS’ therapeutic potential for individuals with clinical levels of anxiety.

Neurocognitive effects of 3 mA prefrontal electrical stimulation in schizophrenia: A randomized sham-controlled tDCS-fMRI study protocol.

Schizophrenia (SCZ) is characterized by cognitive deficits that are linked to prefrontal cortex dysfunction. While transcranial direct current stimulation (tDCS) shows promise for improving cognition, the effects of intensified 3mA tDCS protocols on brain physiology are unknown. This project aims to elucidate the neurophysiological and cognitive effects of an intensified prefrontal tDCS protocol in SCZ. The study is designed as a randomized, double-blind, 2-arm parallel-group, sham-controlled, trial. Forty-eight participants with SCZ and cognitive impairment (measured via a set of executive functions tests) will be randomly allocated to receive either a single session of active (n = 24) or sham (n = 24) tDCS (20-min, 3-mA). The anodal and cathodal electrodes are positioned over the left and right DLPFC respectively. The stimulation occurs concurrently with the working memory task, which is initiated precisely 5 minutes after the onset of tDCS. Structural and resting-state (rs-fMRI) scans are conducted immediately before and after both active and sham tDCS using a 3 Tesla scanner (Siemens Prisma model) equipped with a 64-channel head coil. The primary outcome will be changes in brain activation (measures vis BOLD response) and working memory performance (accuracy, reaction time). The results of this study are helpful in optimizing tDCS protocols in SCZ and inform us of neurocognitive mechanisms underlying 3 mA stimulation. This study will additionally provide initial safety and efficacy data on a 3 mA tDCS protocol to support larger clinical trials. Positive results could lead to rapid and broader testing of a promising tool for debilitating symptoms that affect the majority of patients with SCZ. The results will be made available through publications in peer-reviewed journals and presentations at national and international conferences.

Impaired maturation of resting-state connectivity in anorexia nervosa from adolescence to adulthood: differential mechanisms of consummatory vs. anticipatory responses through a symptom provocation paradigm.

This functional magnetic resonance imaging (fMRI) study examined resting-state (RS) connectivity in adolescent and adult patients with anorexia nervosa (AN) using symptom provocation paradigms. Differential food reward mechanisms were investigated through separate assessments of responses to food images and low-caloric/high-caloric food consumption. Thirteen young (≤ 21 years) and seventeen adult (> 21 years) patients with AN and age-matched controls underwent two stimulus-driven fMRI sessions involving RS scans before and after the presentation of food-related stimuli and food consumption. Graph theory and machine learning were used for analyzing the fMRI and clinical data. Healthy controls (HCs) showed widespread developmental changes, while young participants with AN exhibited cerebellum differences for high-calorie food. Young individuals with AN displayed increased connectivity during the consumption of potato chips compared to zucchini, with no differences in adults with AN. Multiparametric machine learning accurately distinguished young individuals with AN from healthy controls based on RS connectivity following food visual stimulation ("anticipatory") and consumption ("consummatory"). This study highlights the differential food reward mechanisms and minimal developmental changes in RS connectivity from youth to adulthood in individuals with AN compared to healthy controls. Young individuals with AN demonstrated heightened reactivity to high-caloric foods, while adults showed decreased responsiveness, potentially due to desensitization. These findings shed light on aberrant eating behaviors in individuals with AN and contribute to our understanding of the chronicity of the disease.

Functional connectivity patterns in parosmia

ObjectiveParosmia is a qualitative olfactory dysfunction presenting as “distorted odor perception” in presence of an odor source. Aim of this study was to use resting state functional connectivity to gain more information on the alteration of olfactory processing at the level of the central nervous system level.MethodsA cross sectional study was performed in 145 patients with parosmia (age range 20–76 years; 90 women). Presence and degree of parosmia was diagnosed on the basis of standardized questionnaires. Participants also received olfactory testing using the “Sniffin’ Sticks”. Then they underwent resting state scans using a 3 T magnetic resonance imaging scanner while fixating on a cross.ResultsWhole brain analyses revealed reduced functional connectivity in salience as well as executive control networks. Region of interest-based analyses also supported reduced functional connectivity measures between primary and secondary olfactory eloquent areas (temporal pole, supramarginal gyrus and right orbitofrontal cortex; dorso-lateral pre-frontal cortex and the right piriform cortex).ConclusionsParticipants with parosmia exhibited a reduced information flow between memory, decision making centers, and primary and secondary olfactory areas.

Exploring static and dynamic functional brain networks in adolescent depression using a co-produced novel irritability paradigm

Background Irritability is a core symptom of depression in adolescence and a risk factor for emotion regulation problems. However, its neural correlates are not well understood. Existing functional magnetic resonance imaging (fMRI) research on irritability typically overlooks its social context. Methods Here, we pilot a novel naturalistic fMRI paradigm targeting the social nature of irritability that was co-produced with young people (N = 88) and apply it in an independent sample of youth (N = 29, mean age 18.9 years, 77% female) with self-reported low mood that were aged 16 to 20 years. Participants were also fluent English speakers, free from MRI contraindications, and did not report a diagnosis of a neurological or neurodevelopmental condition. Our aim was to investigate whether graph theoretic and dynamical properties of functional brain networks differed between a resting state scan and our irritability paradigm. We also examined whether these brain features were associated with depressive symptoms and trait irritability. Results Using Leading Eigenvector Dynamics Analysis (LEiDA), we found that the dynamic properties of brain networks comprising default-mode and fronto-parietal regions differed significantly during the irritability paradigm compared to the rest condition. While no gross static topological differences were found between these two conditions, we found that some dynamic and topological features of emotion-related brain networks were related to trait irritability and depressive symptoms in our sample. Conclusions Although the current findings are preliminary due to the pilot nature of this study, this work showcases the feasibility of co-produced research in neuroimaging and lays a strong foundation for further study.

The triple psychological and neural bases underlying procrastination: Evidence based on a two-year longitudinal study

The triple brain anatomical network model of procrastination theorized procrastination as the result of psychological and neural dysfunction implicated in self-control, emotion regulation and episodic prospection. However, no studies have provided empirical evidence for such model. To address this issue, we designed a two-wave longitudinal study where participants underwent the resting-state scanning and completed the questionnaires at two time-points that spanned 2-year apart (T1, n = 457; T2, n = 457). Using the cross-lagged panel network modeling (CLPN), we found that triple psychological components at T1, including self-control, emotion regulation (i.e., reappraisal) and episodic prospection, negatively predicted procrastination at T2 in the temporal network. Moreover, the CLPN modeling found that functional connectivity between networks accounting for episodic prospection (EP) and emotion regulation (ER) positively predicted future procrastination in the temporal network. The centrality analyzes further showed that procrastination was greatly affected by other nodes, whilst the psychological component (i.e., episodic prospection), and the functional network connectivity (FNC) of EP- ER exerted strongest impacts on other nodes in the networks, which indicated that treatments targeting episodic prospection might largely help reduce procrastination. Collectively, these findings firstly provide evidence for testifying the triple brain anatomical network model of procrastination, and highlights the contribution of triple psychological and neural components implicated in self-control, emotion regulation and episodic prospection to procrastination that enhances our understanding of causes of procrastination.