New resting-state fMRI related studies at PubMed

Subscribe to New resting-state fMRI related studies at PubMed feed New resting-state fMRI related studies at PubMed
NCBI: db=pubmed; Term=resting state fMRI
Updated: 3 hours 2 min ago

Heritability estimates on resting state fMRI data using ENIGMA analysis pipeline.

Sat, 12/09/2017 - 16:40
Related Articles

Heritability estimates on resting state fMRI data using ENIGMA analysis pipeline.

Pac Symp Biocomput. 2018;23:307-318

Authors: Adhikari BM, Jahanshad N, Shukla D, Glahn DC, Blangero J, Reynolds RC, Cox RW, Fieremans E, Veraart J, Novikov DS, Nichols TE, Hong LE, Thompson PM, Kochunov P

Abstract
Big data initiatives such as the Enhancing NeuroImaging Genetics through Meta-Analysis consortium (ENIGMA), combine data collected by independent studies worldwide to achieve more generalizable estimates of effect sizes and more reliable and reproducible outcomes. Such efforts require harmonized image analyses protocols to extract phenotypes consistently. This harmonization is particularly challenging for resting state fMRI due to the wide variability of acquisition protocols and scanner platforms; this leads to site-to-site variance in quality, resolution and temporal signal-to-noise ratio (tSNR). An effective harmonization should provide optimal measures for data of different qualities. We developed a multi-site rsfMRI analysis pipeline to allow research groups around the world to process rsfMRI scans in a harmonized way, to extract consistent and quantitative measurements of connectivity and to perform coordinated statistical tests. We used the single-modality ENIGMA rsfMRI preprocessing pipeline based on modelfree Marchenko-Pastur PCA based denoising to verify and replicate resting state network heritability estimates. We analyzed two independent cohorts, GOBS (Genetics of Brain Structure) and HCP (the Human Connectome Project), which collected data using conventional and connectomics oriented fMRI protocols, respectively. We used seed-based connectivity and dual-regression approaches to show that the rsfMRI signal is consistently heritable across twenty major functional network measures. Heritability values of 20-40% were observed across both cohorts.

PMID: 29218892 [PubMed - in process]

Brain connectivity in children is increased by the time they spend reading books and decreased by the length of exposure to screen-based media.

Fri, 12/08/2017 - 15:40

Brain connectivity in children is increased by the time they spend reading books and decreased by the length of exposure to screen-based media.

Acta Paediatr. 2017 Dec 07;:

Authors: Horowitz-Kraus T, Hutton JS

Abstract
AIM: This study compared the time spent using screen-based media or reading on the functional connectivity of the reading-related brain regions in children aged 8-12.
METHODS: We recruited 19 healthy American children from a private school in Cincinnati, USA, in 2015-6 after advertising the study to parents. The parents completed surveys on how many hours their children spent on independent reading and screen-based media time, including smartphones, tablets, desktop or laptop computers and television. The children underwent magnetic resonance imaging that assessed their resting-state connectivity between the left visual word form area, as the seed area, and other brain regions, with screen time and reading time applied as predictors.
RESULTS: Time spent reading was positively correlated with higher functional connectivity between the seed area and left-sided language, visual and cognitive control regions. In contrast, screen time was related to lower connectivity between the seed area and regions related to language and cognitive control.
CONCLUSION: Screen time and time spent reading showed different effects on functional connectivity between the visual word form area and language, visual and cognitive-control regions of the brain. These findings underscore the importance of children reading to support healthy brain development and literacy and limiting screen time. This article is protected by copyright. All rights reserved.

PMID: 29215151 [PubMed - as supplied by publisher]

[Neuronet restructuring in focal and generalized epilepsy according to resting state fMRI].

Fri, 12/08/2017 - 15:40

[Neuronet restructuring in focal and generalized epilepsy according to resting state fMRI].

Zh Nevrol Psikhiatr Im S S Korsakova. 2017;117(9. Vyp. 2):4-9

Authors: Mayorova LA, Samotaeva IS, Lebedeva NN, Luzin RV, Gaskin VV, Rider FK, Teplyshova AM, Akzhigitov RG, Guekht AB

Abstract
AIM: To compare neuronet restructuring in focal and generalized epilepsy.
MATERIAL AND METHODS: Seventy-seven patients, aged from 18 to 65 years, with the diagnosis of epilepsy, including 63 patients with focal epilepsy and 14 with generalized epilepsy, were examined. A control group included 23 healthy people. Neuronet restructuring was studied using fMRI.
RESULTS AND CONCLUSION: According to resting state fMRI, there were between-group differences in spatial organization (activity map) of the brain structures as well as in the results of cross-correlation analysis of interaction maps of resting-state networks. It has been concluded that functional restructuring in connectomes in focal and generalized epilepsy have the opposite patterns of disorganization (toward increase or decrease) in most structures studied though there are structures with the same direction of connectivity changes.

PMID: 29213031 [PubMed - in process]

Aberrant resting-state functional connectivity in limbic and cognitive control networks relates to depressive rumination and mindfulness: A pilot study among adolescents with a history of depression.

Fri, 12/08/2017 - 15:40
Related Articles

Aberrant resting-state functional connectivity in limbic and cognitive control networks relates to depressive rumination and mindfulness: A pilot study among adolescents with a history of depression.

J Affect Disord. 2016 Aug;200:178-81

Authors: Peters AT, Burkhouse K, Feldhaus CC, Langenecker SA, Jacobs RH

Abstract
BACKGROUND: Resting state functional connectivity (RSFC) research among adults indicates abnormalities within and between neural networks during acute depressive episodes, some of which are likely to remain into remission. The examination of RSFC among adolescents within the remitted state of MDD may implicate markers of illness course during a critical developmental window wherein secondary prevention can be implemented.
METHODS: RSFC data were collected on a 3.0T GE scanner from adolescents (12-18, M=15.61, SD=1.90; 57% female) in full or partial remission from MDD (rMDD; n=23) and age- and gender-matched healthy controls (HC; n=10). RSFC data were examined using seed-based connectivity of the left amygdala, left dorsolateral prefrontal cortex (dlPFC), and left posterior cingulate cortex (PCC). These seeds were chosen to probe the emotional salience, cognitive control, and default mode networks, respectively.
RESULTS: rMDD adolescents demonstrated relative hyperconnectivity from the left amygdala to the right PCC, as well as from the left dlPFC to the right middle frontal and left inferior frontal gyri (MFG, IFG). Amygdala to PCC connectivity was correlated with greater rumination, dlPFC to MFG connectivity was positively associated with depression severity, and dlPFC to IFG connectivity was inversely associated with mindfulness.
CONCLUSIONS: Aberrant functional connectivity within and between neural networks responsible for salience attribution, introspective thought, and executive control can be observed among adolescents in the remitted phase of MDD and is associated with residual clinical symptoms. These patterns may confer risk for future relapse or alternatively, support wellness.

PMID: 27136416 [PubMed - indexed for MEDLINE]

Spectral Diversity in Default Mode Network Connectivity Reflects Behavioral State.

Thu, 12/07/2017 - 14:20

Spectral Diversity in Default Mode Network Connectivity Reflects Behavioral State.

J Cogn Neurosci. 2017 Dec 06;:1-14

Authors: Craig MM, Manktelow AE, Sahakian BJ, Menon DK, Stamatakis EA

Abstract
Default mode network (DMN) functional connectivity is thought to occur primarily in low frequencies (<0.1 Hz), resulting in most studies removing high frequencies during data preprocessing. In contrast, subtractive task analyses include high frequencies, as these are thought to be task relevant. An emerging line of research explores resting fMRI data at higher-frequency bands, examining the possibility that functional connectivity is a multiband phenomenon. Furthermore, recent studies suggest DMN involvement in cognitive processing; however, without a systematic investigation of DMN connectivity during tasks, its functional contribution to cognition cannot be fully understood. We bridged these concurrent lines of research by examining the contribution of high frequencies in the relationship between DMN and dorsal attention network at rest and during task execution. Our findings revealed that the inclusion of high frequencies alters between network connectivity, resulting in reduced anticorrelation and increased positive connectivity between DMN and dorsal attention network. Critically, increased positive connectivity was observed only during tasks, suggesting an important role for high-frequency fluctuations in functional integration. Moreover, within-DMN connectivity during task execution correlated with RT only when high frequencies were included. These results show that DMN does not simply deactivate during task execution and suggest active recruitment while performing cognitively demanding paradigms.

PMID: 29211655 [PubMed - as supplied by publisher]

Auditory Related Resting State fMRI Functional Connectivity in Tinnitus Patients: Tinnitus Diagnosis Performance.

Thu, 12/07/2017 - 14:20

Auditory Related Resting State fMRI Functional Connectivity in Tinnitus Patients: Tinnitus Diagnosis Performance.

Otol Neurotol. 2017 Nov 28;:

Authors: Minami SB, Oishi N, Watabe T, Uno K, Ogawa K

Abstract
OBJECTIVE: The purpose of the present study was to investigate functional connectivity in tinnitus patients with and without hearing loss, and design the tinnitus diagnosis performance by resting state functional magnetic resonance imaging (rs-fMRI).
SUBJECTS AND METHODS: Nineteen volunteers with normal hearing without tinnitus, 18 tinnitus patients with hearing loss, and 11 tinnitus patients without hearing loss were enrolled in this study. The subjects were evaluated with rs-fMRI, and region of interests (ROIs) based correlation analyses were performed using the CONN toolbox version 16 and SPM version 8. The correlation coefficients from individual level results were converted into beta values.
RESULTS: With a beta threshold of more than 0.2, 91% of all possible connections between auditory-related ROIs (Heschl's gyrus, planum temporale, planum polare, operculum, insular cortex, superior temporal gyrus) in the control group remained intact, whereas 83 and 66% of such connections were present in the hearing loss and the normal-hearing tinnitus group. However, between non-auditory-related ROIs, the rates of intact connections at a beta threshold of more than 0.2 were 17% in the control group, and 16 and 15% in the tinnitus groups. When resting state fMRI positive is defined as less than 9% of all possible connections between auditory-related ROIs with a beta threshold of more than 0.7, the sensitivity and specificity of tinnitus diagnosis is 86 and 74%, respectively.
CONCLUSIONS: The associations between auditory-related networks are weakened in tinnitus patients, even if they have normal hearing. It is possible that rs-fMRI can be a tool for objective examination of tinnitus, by focusing the auditory-related areas.

PMID: 29210942 [PubMed - as supplied by publisher]

Disrupted Control-Related Functional Brain Networks in Drug-Naive Children with Attention-Deficit/Hyperactivity Disorder.

Thu, 12/07/2017 - 14:20
Related Articles

Disrupted Control-Related Functional Brain Networks in Drug-Naive Children with Attention-Deficit/Hyperactivity Disorder.

Front Psychiatry. 2017;8:246

Authors: Tao J, Jiang X, Wang X, Liu H, Qian A, Yang C, Chen H, Li J, Ye Q, Wang J, Wang M

Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disease featuring executive control deficits as a prominent neuropsychological trait. Executive functions are implicated in multiple sub-networks of the brain; however, few studies examine these sub-networks as a whole in ADHD. By combining resting-state functional MRI and graph-based approaches, we systematically investigated functional connectivity patterns among four control-related networks, including the frontoparietal network (FPN), cingulo-opercular network, cerebellar network, and default mode network (DMN), in 46 drug-naive children with ADHD and 31 age-, gender-, and intelligence quotient-matched healthy controls (HCs). Compared to the HCs, the ADHD children showed significantly decreased functional connectivity that primarily involved the DMN and FPN regions and cross-network long-range connections. Further graph-based network analysis revealed that the ADHD children had fewer connections, lower network efficiency, and more functional modules compared with the HCs. The ADHD-related alterations in functional connectivity but not topological organization were correlated with clinical symptoms of the ADHD children and differentiated the patients from the HCs with a good performance. Taken together, our findings suggest a less-integrated functional brain network in children with ADHD due to selective disruption of key long-range connections, with important implications for understanding the neural substrates of ADHD, particularly executive dysfunction.

PMID: 29209238 [PubMed]

Altered Brain Functional Connectivity in Betel Quid-Dependent Chewers.

Thu, 12/07/2017 - 14:20
Related Articles

Altered Brain Functional Connectivity in Betel Quid-Dependent Chewers.

Front Psychiatry. 2017;8:239

Authors: Huang X, Pu W, Liu H, Li X, Greenshaw AJ, Dursun SM, Xue Z, Liu Z

Abstract
Background: Betel quid (BQ) is a common psychoactive substance worldwide with particularly high usage in many Asian countries. This study aimed to explore the effect of BQ use on functional connectivity by comparing global functional brain networks and their subset between BQ chewers and healthy controls (HCs).
Methods: Resting-state functional magnetic resonance imaging (fMRI) was obtained from 24 betel quid-dependent (BQD) male chewers and 27 healthy male individuals on a 3.0T scanner. We used independent component analysis (ICA) to determine components that represent the brain's functional networks and their spatial aspects of functional connectivity. Two sample t-tests were used to identify the functional connectivity differences in each network between these two groups.
Results: Seventeen networks were identified by ICA. Nine of them showed connectivity differences between BQD and HCs (two sample t-tests, p < 0.001 uncorrected). We found increased functional connectivity in the orbitofrontal, bilateral frontoparietal, frontotemporal, occipital/parietal, frontotemporal/cerebellum, and temporal/limbic networks, and decreased connectivity in the parietal and medial frontal/anterior cingulate networks in the BQD compared to the HCs. The betel quid dependence scale scores were positively related to the increased functional connectivity in the orbitofrontal (r = 0.39, p = 0.03) while negatively related to the decreased functional connectivity in medial frontal/anterior cingulate networks (r = -0.35, p = 0.02).
Discussion: Our findings provide further evidence that BQ chewing may lead to brain functional connectivity changes, which may play a key role in the psychological and physiological effects of BQ.

PMID: 29209234 [PubMed]

Decreased Complexity in Alzheimer's Disease: Resting-State fMRI Evidence of Brain Entropy Mapping.

Thu, 12/07/2017 - 14:20
Related Articles

Decreased Complexity in Alzheimer's Disease: Resting-State fMRI Evidence of Brain Entropy Mapping.

Front Aging Neurosci. 2017;9:378

Authors: Wang B, Niu Y, Miao L, Cao R, Yan P, Guo H, Li D, Guo Y, Yan T, Wu J, Xiang J, Zhang H

Abstract
Alzheimer's disease (AD) is a frequently observed, irreversible brain function disorder among elderly individuals. Resting-state functional magnetic resonance imaging (rs-fMRI) has been introduced as an alternative approach to assessing brain functional abnormalities in AD patients. However, alterations in the brain rs-fMRI signal complexities in mild cognitive impairment (MCI) and AD patients remain unclear. Here, we described the novel application of permutation entropy (PE) to investigate the abnormal complexity of rs-fMRI signals in MCI and AD patients. The rs-fMRI signals of 30 normal controls (NCs), 33 early MCI (EMCI), 32 late MCI (LMCI), and 29 AD patients were obtained from the Alzheimer's disease Neuroimaging Initiative (ADNI) database. After preprocessing, whole-brain entropy maps of the four groups were extracted and subjected to Gaussian smoothing. We performed a one-way analysis of variance (ANOVA) on the brain entropy maps of the four groups. The results after adjusting for age and sex differences together revealed that the patients with AD exhibited lower complexity than did the MCI and NC controls. We found five clusters that exhibited significant differences and were distributed primarily in the occipital, frontal, and temporal lobes. The average PE of the five clusters exhibited a decreasing trend from MCI to AD. The AD group exhibited the least complexity. Additionally, the average PE of the five clusters was significantly positively correlated with the Mini-Mental State Examination (MMSE) scores and significantly negatively correlated with Functional Assessment Questionnaire (FAQ) scores and global Clinical Dementia Rating (CDR) scores in the patient groups. Significant correlations were also found between the PE and regional homogeneity (ReHo) in the patient groups. These results indicated that declines in PE might be related to changes in regional functional homogeneity in AD. These findings suggested that complexity analyses using PE in rs-fMRI signals can provide important information about the fMRI characteristics of cognitive impairments in MCI and AD.

PMID: 29209199 [PubMed]

Asymmetry of Hemispheric Network Topology Reveals Dissociable Processes between Functional and Structural Brain Connectome in Community-Living Elders.

Thu, 12/07/2017 - 14:20
Related Articles

Asymmetry of Hemispheric Network Topology Reveals Dissociable Processes between Functional and Structural Brain Connectome in Community-Living Elders.

Front Aging Neurosci. 2017;9:361

Authors: Sun Y, Li J, Suckling J, Feng L

Abstract
Human brain is structurally and functionally asymmetrical and the asymmetries of brain phenotypes have been shown to change in normal aging. Recent advances in graph theoretical analysis have showed topological lateralization between hemispheric networks in the human brain throughout the lifespan. Nevertheless, apparent discrepancies of hemispheric asymmetry were reported between the structural and functional brain networks, indicating the potentially complex asymmetry patterns between structural and functional networks in aging population. In this study, using multimodal neuroimaging (resting-state fMRI and structural diffusion tensor imaging), we investigated the characteristics of hemispheric network topology in 76 (male/female = 15/61, age = 70.08 ± 5.30 years) community-dwelling older adults. Hemispheric functional and structural brain networks were obtained for each participant. Graph theoretical approaches were then employed to estimate the hemispheric topological properties. We found that the optimal small-world properties were preserved in both structural and functional hemispheric networks in older adults. Moreover, a leftward asymmetry in both global and local levels were observed in structural brain networks in comparison with a symmetric pattern in functional brain network, suggesting a dissociable process of hemispheric asymmetry between structural and functional connectome in healthy older adults. Finally, the scores of hemispheric asymmetry in both structural and functional networks were associated with behavioral performance in various cognitive domains. Taken together, these findings provide new insights into the lateralized nature of multimodal brain connectivity, highlight the potentially complex relationship between structural and functional brain network alterations, and augment our understanding of asymmetric structural and functional specializations in normal aging.

PMID: 29209197 [PubMed]

The Neural Association between Tendency to Forgive and Spontaneous Brain Activity in Healthy Young Adults.

Thu, 12/07/2017 - 14:20
Related Articles

The Neural Association between Tendency to Forgive and Spontaneous Brain Activity in Healthy Young Adults.

Front Hum Neurosci. 2017;11:561

Authors: Li H, Lu J

Abstract
The tendency to forgive (TTF) refers to one's global dispositional level of forgiveness across situations and relationships. Previous brain imaging studies examined activation patterns underlying forgiving process, yet the association between individual differences in the TTF and spontaneous brain activity at resting-state remains unknown. In this study, resting-state functional magnetic resonance imaging (fMRI) was used to investigate the correlation between the TTF and spontaneous brain activity in a young adult sample. Participants were 178 young students (55 men) who completed the TTF scale and underwent a resting-state fMRI scan. Multiple regression analysis was conducted to assess the association between the regional amplitude of low-frequency fluctuations (ALFF) and TTF scores corrected for age and sex. Results showed that the ALFF value in the right dorsomedial prefrontal cortex (dmPFC), precuneus and inferior parietal lobule (IPL) were negatively associated with TTF scores. These findings suggest that the spontaneous brain activity of brain regions like the dmPFC, precuneus and IPL which are implicated in mentalizing and empathic response are associated with individual differences in the TTF.

PMID: 29209186 [PubMed]

A digital 3D atlas of the marmoset brain based on multi-modal MRI.

Thu, 12/07/2017 - 14:20
Related Articles

A digital 3D atlas of the marmoset brain based on multi-modal MRI.

Neuroimage. 2017 Dec 02;:

Authors: Liu C, Ye FQ, Chern-Chyi Yen C, Newman JD, Glen D, Leopold DA, Silva AC

Abstract
The common marmoset (Callithrix jacchus) is a New-World monkey of growing interest in neuroscience. Magnetic resonance imaging (MRI) is an essential tool to unveil the anatomical and functional organization of the marmoset brain. To facilitate identification of regions of interest, it is desirable to register MR images to an atlas of the brain. However, currently available atlases of the marmoset brain are mainly based on 2D histological data, which are difficult to apply to 3D imaging techniques. Here, we constructed a 3D digital atlas based on high-resolution ex-vivo MRI images, including magnetization transfer ratio (a T1-like contrast), T2w images, and multi-shell diffusion MRI. Based on the multi-modal MRI images, we manually delineated 54 cortical areas and 16 subcortical regions on one hemisphere of the brain (the core version). The 54 cortical areas were merged into 13 larger cortical regions according to their locations to yield a coarse version of atlas, and also parcellated into 106 sub-regions using a connectivity-based parcellation method to produce a refined atlas. Finally, we compared the new atlas set with existing histology atlases and demonstrated its applications in connectome studies, and in resting state and stimulus-based fMRI. The atlas set has been integrated into the widely-distributed neuroimaging data analysis software AFNI and SUMA, providing a readily usable multi-modal template space with multi-level anatomical labels (including labels from the Paxinos atlas) that can facilitate various neuroimaging studies of marmosets.

PMID: 29208569 [PubMed - as supplied by publisher]

Differential patterns of dynamic functional connectivity variability of striato-cortical circuitry in children with benign epilepsy with centrotemporal spikes.

Wed, 12/06/2017 - 13:20
Related Articles

Differential patterns of dynamic functional connectivity variability of striato-cortical circuitry in children with benign epilepsy with centrotemporal spikes.

Hum Brain Mapp. 2017 Dec 05;:

Authors: Li R, Liao W, Yu Y, Chen H, Guo X, Tang YL, Chen H

Abstract
Benign epilepsy with centrotemporal spikes (BECTS) is characterized by abnormal (static) functional interactions among cortical and subcortical regions, regardless of the active or chronic epileptic state. However, human brain connectivity is dynamic and associated with ongoing rhythmic activity. The dynamic functional connectivity (dFC) of the distinct striato-cortical circuitry associated with or without interictal epileptiform discharges (IEDs) are poorly understood in BECTS. Herein, we captured the pattern of dFC using sliding window correlation of putamen subregions in the BECTS (without IEDs, n = 23; with IEDs, n = 20) and sex- and age-matched healthy controls (HCs, n = 28) during rest. Furthermore, we quantified dFC variability using their standard deviation. Compared with HCs and patients without IEDs, patients with IEDs exhibited excessive variability in the dorsal striatal-sensorimotor circuitry related to typical seizure semiology. By contrast, excessive stability (decreased dFC variability) was found in the ventral striatal-cognitive circuitry (p < .05, GRF corrected). In addition, correlation analysis revealed that the excessive variability in the dorsal striatal-sensorimotor circuitry was related to highly frequent IEDs (p < .05, uncorrected). Our finding of excessive variability in the dorsal striatal-sensorimotor circuitry could be an indication of increased sensitivity to regional fluctuations in the epileptogenic zone, while excessive stability in the ventral striatal-cognitive circuitry could represent compensatory mechanisms that prevent or postpone cognitive impairments in BECTS. Overall, the differentiated dynamics of the striato-cortical circuitry extend our understanding of interactions among epileptic activity, striato-cortical functional architecture, and neurocognitive processes in BECTS.

PMID: 29206330 [PubMed - as supplied by publisher]

Changing brain connectivity dynamics: From early childhood to adulthood.

Wed, 12/06/2017 - 13:20
Related Articles

Changing brain connectivity dynamics: From early childhood to adulthood.

Hum Brain Mapp. 2017 Dec 05;:

Authors: Faghiri A, Stephen JM, Wang YP, Wilson TW, Calhoun VD

Abstract
Brain maturation through adolescence has been the topic of recent studies. Previous works have evaluated changes in morphometry and also changes in functional connectivity. However, most resting-state fMRI studies have focused on static connectivity. Here we examine the relationship between age/maturity and the dynamics of brain functional connectivity. Utilizing a resting fMRI dataset comprised 421 subjects ages 3-22 from the PING study, we first performed group ICA to extract independent components and their time courses. Next, dynamic functional network connectivity (dFNC) was calculated via a sliding window followed by clustering of connectivity patterns into 5 states. Finally, we evaluated the relationship between age and the amount of time each participant spent in each state as well as the transitions among different states. Results showed that older participants tend to spend more time in states which reflect overall stronger connectivity patterns throughout the brain. In addition, the relationship between age and state transition is symmetric. This can mean individuals change functional connectivity through time within a specific set of states. On the whole, results indicated that dynamic functional connectivity is an important factor to consider when examining brain development across childhood.

PMID: 29205692 [PubMed - as supplied by publisher]

Different pre-scanning instructions induce distinct psychological and resting brain states during functional magnetic resonance imaging.

Wed, 12/06/2017 - 13:20
Related Articles

Different pre-scanning instructions induce distinct psychological and resting brain states during functional magnetic resonance imaging.

Eur J Neurosci. 2017 Dec 04;:

Authors: Kawagoe T, Onoda K, Yamaguchi S

Abstract
Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to investigate functional brain network connectivity during rest or when the subject is not performing an explicit task. In the standard procedure, subjects are instructed to "let your mind wander" or "think of nothing." While these instructions appear appropriate to induce a "resting-state," they could induce distinct psychological and physiological states during the scan. In this study, we investigated whether different instructions affect mental state and functional connectivity (FC) (i.e., induce distinct "resting states") during rs-fMRI scanning. Thirty healthy subjects were subjected to two rs-fMRI scans differing only in pre-scan instructions: think of nothing (TN) and mind wandering (MW) conditions. Self-reports confirmed that subjects spent the majority of the scanning time in the appropriate mental state. Independent component analysis extracted 19 independent components (ICs) of interest and functional network connectivity analyses indicated several conditional differences of FCs among those ICs, especially characterized by stronger FC in the MW condition than in the TN condition, between default mode network and salience/visual/frontal network. Complementary correlation analysis indicated that some of the network FCs were significantly correlated with their self-reported data on how often they had the TN condition during the scans. The present results provide evidence that the pre-scan instruction has a significant influence on resting-state FC and its relationship with mental activities. This article is protected by copyright. All rights reserved.

PMID: 29205574 [PubMed - as supplied by publisher]

Interactive effects of seizure frequency and lateralization on intratemporal effective connectivity in temporal lobe epilepsy.

Wed, 12/06/2017 - 13:20
Related Articles

Interactive effects of seizure frequency and lateralization on intratemporal effective connectivity in temporal lobe epilepsy.

Epilepsia. 2017 Dec 04;:

Authors: Park CH, Choi YS, Kim HJ, Chung HK, Jung AR, Yoo JH, Lee HW

Abstract
OBJECTIVE: Patients with temporal lobe epilepsy (TLE) show brain connectivity changes in association with cognitive impairment. Seizure frequency and lateralization are 2 important clinical factors that characterize epileptic seizures. In this study, we sought to examine an interactive effect of the 2 seizure factors on intratemporal effective connectivity based on resting-state functional magnetic resonance imaging (rsfMRI) in patients with TLE.
METHODS: For rsfMRI data acquired from 48 TLE patients and 45 healthy controls, we applied stochastic dynamical causal modeling to infer effective connectivity between 3 medial temporal lobe (MTL) regions, including the hippocampus (Hipp), parahippocampal gyrus (PHG), and amygdala (Amyg), ipsilateral to the seizure focus. We searched for the effect of the 2 seizure factors, seizure frequency (good vs poor seizure control) and lateralization (left vs right TLE), on connection strengths and their relationship with the level of verbal memory and language impairment.
RESULTS: Impairment of verbal memory and language function was mainly affected by seizure lateralization, consistent with preferential involvement of the left MTL in verbal mnemonic processing. For the fully connected model, which was selected as the effective connectivity structure that best explained the observed rsfMRI time series, alterations in connection strengths were primarily influenced by seizure frequency; there was an increase in the strength of the Hipp to PHG connection in TLE patients with poor seizure control, whereas the strength of the Amyg to PHG connection increased in those with good seizure control. Furthermore, the association between connection strength alterations and cognitive impairment was interactively affected by both seizure frequency and lateralization.
SIGNIFICANCE: These findings suggest an interactive effect as well as an individual effect of seizure frequency and lateralization on neuroimaging features and cognitive function. This potential interaction needs to be evaluated in the consideration of multiple seizure factors.

PMID: 29205291 [PubMed - as supplied by publisher]

Analysis of fMRI data using noise-diffusion network models: a new covariance-coding perspective.

Wed, 12/06/2017 - 13:20
Related Articles

Analysis of fMRI data using noise-diffusion network models: a new covariance-coding perspective.

Biol Cybern. 2017 Dec 04;:

Authors: Gilson M

Abstract
Since the middle of the 1990s, studies of resting-state fMRI/BOLD data have explored the correlation patterns of activity across the whole brain, which is referred to as functional connectivity (FC). Among the many methods that have been developed to interpret FC, a recently proposed model-based approach describes the propagation of fluctuating BOLD activity within the recurrently connected brain network by inferring the effective connectivity (EC). In this model, EC quantifies the strengths of directional interactions between brain regions, viewed from the proxy of BOLD activity. In addition, the tuning procedure for the model provides estimates for the local variability (input variances) to explain how the observed FC is generated. Generalizing, the network dynamics can be studied in the context of an input-output mapping-determined by EC-for the second-order statistics of fluctuating nodal activities. The present paper focuses on the following detection paradigm: observing output covariances, how discriminative is the (estimated) network model with respect to various input covariance patterns? An application with the model fitted to experimental fMRI data-movie viewing versus resting state-illustrates that changes in local variability and changes in brain coordination go hand in hand.

PMID: 29204807 [PubMed - as supplied by publisher]

Effect of Electro-Acupuncture and Moxibustion on Brain Connectivity in Patients with Crohn's Disease: A Resting-State fMRI Study.

Wed, 12/06/2017 - 13:20
Related Articles

Effect of Electro-Acupuncture and Moxibustion on Brain Connectivity in Patients with Crohn's Disease: A Resting-State fMRI Study.

Front Hum Neurosci. 2017;11:559

Authors: Bao C, Wang D, Liu P, Shi Y, Jin X, Wu L, Zeng X, Zhang J, Liu H, Wu H

Abstract
Acupuncture and moxibustion have been shown to be effective in treating Crohn's disease (CD), but their therapeutic mechanisms remain unclear. Here we compared brain responses to either electro-acupuncture or moxibustion treatment in CD patients experiencing remission. A total of 65 patients were randomly divided into an electro-acupuncture group (n = 32) or a moxibustion group (n = 33), and treated for 12 weeks. Eighteen patients in the electro-acupuncture group and 20 patients in the moxibustion group underwent resting-state functional magnetic resonance imaging at baseline and after treatment. Seed-based analysis was used to compare the resting-state functional connectivity (rsFC) between bilateral hippocampus and other brain regions before and after the treatments, as well as between the two groups. The CD activity index (CDAI) and inflammatory bowel disease questionnaire (IBDQ) were used to evaluate disease severity and patient quality of life. Electro-acupuncture and moxibustion both significantly reduced CDAI values and increased IBDQ scores. In the electro-acupuncture group, the rsFC values between bilateral hippocampus and anterior middle cingulate cortex (MCC) and insula were significantly increased, and the changes were negatively correlated with the CDAI scores. In the moxibustion group, the rsFC values between bilateral hippocampus and precuneus as well as inferior parietal lobe (IPC) were significantly elevated, and the changes were negatively correlated with the CDAI scores. We conclude that the therapeutic effects of electro-acupuncture and moxibustion on CD may involve the differently modulating brain homeostatic afferent processing network and default mode network (DMN), respectively.

PMID: 29204113 [PubMed]

Aberrant Temporal Connectivity in Persons at Clinical High Risk for Psychosis.

Tue, 12/05/2017 - 12:00

Aberrant Temporal Connectivity in Persons at Clinical High Risk for Psychosis.

Biol Psychiatry Cogn Neurosci Neuroimaging. 2017 Nov;2(8):696-705

Authors: Colibazzi T, Yang Z, Horga G, Chao-Gan Y, Corcoran CM, Klahr K, Brucato G, Girgis R, Abi-Dargham A, Milham MP, Peterson BS

Abstract
Background: Schizophrenia, a neurodevelopmental disorder, involves abnormalities in functional connectivity (FC) across distributed neural networks, which are thought to antedate the emergence of psychosis. In a cohort of adolescents and young adults at clinical high risk (CHR) for psychosis, we applied data-driven approaches to resting-state fMRI data so as to systematically characterize FC abnormalities during this period and determine whether these abnormalities are associated with psychosis risk and severity of psychotic symptoms.
Methods: Fifty-one CHR participants and 47 matched healthy controls (HCs) were included in our analyses. Twelve of these CHR participants developed psychosis within 3.9 years. We estimated one multivariate measure of FC and studied its relationship to CHR status, conversion to psychosis and positive symptom severity.
Results: Multivariate analyses revealed between-group differences in whole-brain connectivity patterns of bilateral temporal areas, mostly affecting their functional connections to the thalamus. Further, more severe positive symptoms were associated with greater connectivity abnormalities in the anterior cingulate and frontal cortex.
Conclusions: Our study demonstrates that the well-established FC abnormalities of the thalamus and temporal areas observed in schizophrenia are also present in the CHR period, with aberrant connectivity of the temporal cortex most associated with psychosis risk.

PMID: 29202110 [PubMed]

Promoter haplotypes of interleukin-10 gene linked to cortex plasticity in subjects with risk of Alzheimer's disease.

Tue, 12/05/2017 - 12:00

Promoter haplotypes of interleukin-10 gene linked to cortex plasticity in subjects with risk of Alzheimer's disease.

Neuroimage Clin. 2018;17:587-595

Authors: Bai F, Xie C, Yuan Y, Shi Y, Zhang Z

Abstract
The Alzheimer's disease (AD) aetiologic event is associated with brain inflammatory processes. In this study, we consider a haplotype of the IL-10 gene promoter region, - 1082A/- 819 T/- 592A (ATA haplotype), which is an additive and independent genetic risk factor for AD. Episodic memory change is the most striking cognitive alteration in AD. It remains unclear whether episodic memory networks can be affected by the ATA haplotype variant in amnestic mild cognitive impairment (aMCI), and if so, how this occurs. Thirty-nine aMCI patients and 30 healthy controls underwent resting-state functional magnetic resonance imaging. An imaging genetics approach was then utilized to investigate disease-related differences in episodic memory networks between the groups based on ATA haplotype-by-aMCI interactions. Gene-brain-behaviour relationships were then further examined. This study found that the ATA haplotype risk variant was associated with abnormal functional communications in the hippocampus-frontoparietal cortices, especially in the left hippocampal network. Moreover, these ATA haplotype carriers showed a distinct phase of hyperactivity in normal aging, with rapid declines of brain function in aMCI subjects when compared to non-ATA haplotype carriers. These findings added to the accumulating evidence that promoter haplotypes of IL-10 may be important modulators of the development of aMCI.

PMID: 29201645 [PubMed - in process]

Pages