New resting-state fMRI related studies at PubMed

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Frequency-specific task modulation of human brain functional networks: a fast fMRI study.

Mon, 09/21/2020 - 19:20
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Frequency-specific task modulation of human brain functional networks: a fast fMRI study.

Neuroimage. 2020 Sep 17;:117375

Authors: Sasai S, Koike T, Sugawara SK, Hamano YH, Sumiya M, Okazaki S, Takahashi HK, Taga G, Sadato N

Abstract
How coherent neural oscillations are involved in task execution is a fundamental question in neuroscience. Although several electrophysiological studies have tackled this issue, the brain-wide task modulation of neural coherence remains uncharacterized. Here, with a fast fMRI technique, we studied shifts of brain-wide neural coherence across different task states in the ultraslow frequency range (0.01-0.7Hz). First, we examined whether the shifts of the brain-wide neural coherence occur in a frequency-dependent manner. We quantified the shift of a region's average neural coherence by the inter-state variance of the mean coherence between the region and the rest of the brain. A clustering analysis based on the variance's spatial correlation between frequency components revealed four frequency bands (0.01-0.15Hz, 0.15-0.37Hz, 0.37-0.53Hz, and 0.53-0.7Hz) showing band-specific shifts of the brain-wide neural coherence. Next, we investigated the similarity of the inter-state variance's spectra between all pairs of regions. We found that regions showing similar spectra correspond to those forming functional modules of the brain network. Then, we investigated the relationship between identified frequency bands and modules' inter-state variances. We found that modules showing the highest variance are those made up of parieto-occipital regions at 0.01-0.15Hz, while it is replaced with another consisting of frontal regions above 0.15Hz. Furthermore, these modules showed specific shifting patterns of the mean coherence across states at 0.01-0.15Hz and above 0.15Hz, suggesting that identified frequency bands differentially contribute to neural interactions during task execution. Our results highlight that usage of the fast fMRI enables brain-wide investigation of neural coherence up to 0.7Hz, which opens a promising track for assessment of the large-scale neural interactions in the ultraslow frequency range.

PMID: 32950690 [PubMed - as supplied by publisher]

Brain Functional Connectivity Correlates of Subclinical Obsessive-Compulsive Symptoms in Healthy Children.

Mon, 09/21/2020 - 19:20
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Brain Functional Connectivity Correlates of Subclinical Obsessive-Compulsive Symptoms in Healthy Children.

J Am Acad Child Adolesc Psychiatry. 2020 Sep 17;:

Authors: Suñol M, Saiz-Masvidal C, Contreras-Rodríguez O, Macià D, Martínez-Vilavella G, Martínez-Zalacaín I, Menchón JM, Pujol J, Sunyer J, Soriano-Mas C

Abstract
OBJECTIVE: The commonly observed Subclinical Obsessive-Compulsive (OC) symptoms in healthy children may predispose to Obsessive-Compulsive Disorder (OCD). Therefore, investigating the underlying neurobiology may be relevant to identify alterations in specific brain circuits potentially accounting for clinical heterogeneity in OCD without the confounding effects of clinical samples. Herein, we analyzed the brain correlates of different OC symptoms in a large group of healthy children using functional connectivity measures.
METHOD: We evaluated 227 healthy children (52% girls, mean age±SD=9.71±0.86 years, range 8-12.1). Participants underwent clinical assessment with the Obsessive-Compulsive Inventory-Child Version and a resting-state functional magnetic resonance imaging examination. Total and symptom-specific severity were correlated with voxel-wise global functional connectivity degree values. Significant clusters were then used as seeds of interest in seed-to-voxel analyses. Modulating effects of age and sex were also assessed.
RESULTS: Global functional connectivity of the left ventral putamen and medial-dorsal thalamus correlated negatively with total OC severity. Seed-to-voxel analyses revealed specific negative correlations from these clusters with limbic, sensorimotor and insular regions in association with obsessing, ordering and doubt-checking symptoms, respectively. Hoarding symptoms were associated with negative correlations between the left medial-dorsal thalamus and a widespread pattern of regions, being such associations modulated by sex and age.
CONCLUSION: Our findings concur with prevailing neurobiological models of OCD on the importance of cortico-striato-thalamo-cortical (CSTC) dysfunction to account for symptom severity. Notably, we showed that changes in CSTC connectivity are present at subclinical stages, which may result in an increased vulnerability for OCD. Moreover, we mapped different symptom dimensions onto specific CSTC circuit attributes.

PMID: 32950652 [PubMed - as supplied by publisher]

Peripheral inflammation is associated with dysfunctional corticostriatal circuitry and executive dysfunction in bipolar disorder patients.

Mon, 09/21/2020 - 19:20
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Peripheral inflammation is associated with dysfunctional corticostriatal circuitry and executive dysfunction in bipolar disorder patients.

Brain Behav Immun. 2020 Sep 17;:

Authors: Tseng HH, Hua Chang H, Wei SY, Lu TH, Hsieh YT, Kuang Yang Y, See Chen P

Abstract
Bipolar disorder (BD) has been linked to abnormal frontal and striatal function, and elevated inflammatory responses. However, the impact of peripheral inflammation on the corticostriatal functional connectivity (FC) remains obscure in BD. The current study aimed to explore the association between peripheral inflammation and corticostriatal connectivity in euthymic BD. We recruited 25 euthymic BD patients and 43 healthy controls (HCs) from the community. Resting state functional images were obtained using 3T magnetic resonance imaging (fMRI), and striatal seed-based whole-brain functional connectivity analyses were performed, with the fasting plasma high-sensitivity C-reactive protein (hs-CRP) level entered as a regressor of interest. The participants also completed the Wisconsin Card-Sorting Test (WCST) and the Continuous Performance Test (CPT). The euthymic BD group had a similar hs-CRP level to the HC group, but a significantly poorer cognitive performance. Compared with the HC group, a higher connectivity between the right dorsal caudal putamen (dcP) and the ventral lateral prefrontal cortex (vlPFC) in the BD group was significantly correlated with a higher hs-CRP level. Stronger dcP-vlPFC connectivity was correlated with a lower CPT unmasked d' in the BD group. BD patients might be particularly sensitive to the effects of inflammation on corticostriatal connectivity. The potentially greater sensitivity of BD patients to peripheral inflammation may differentially modulate the cognitive and reward related corticostriatal circuitry, which may contribute to the pathophysiology of cognitive-affective dysregulation in the euthymic state. Anti-inflammatory or other circuit-specific treatment is warranted for individualized treatment in BD.

PMID: 32950621 [PubMed - as supplied by publisher]

Increased functional homotopy of the prefrontal cortex is associated with corpus callosum degeneration and working memory decline.

Sun, 09/20/2020 - 12:00
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Increased functional homotopy of the prefrontal cortex is associated with corpus callosum degeneration and working memory decline.

Neurobiol Aging. 2020 Aug 25;96:68-78

Authors: Avelar-Pereira B, Bäckman L, Wåhlin A, Nyberg L, Salami A

Abstract
Functional homotopy reflects the link between spontaneous activity in a voxel and its counterpart in the opposite hemisphere. Alterations in homotopic functional connectivity (FC) are seen in normal aging, with highest and lowest homotopy being present in sensory-motor and higher-order regions, respectively. Homotopic FC relates to underlying structural connections, but its neurobiological underpinnings remain unclear. The genu of the corpus callosum joins symmetrical parts of the prefrontal cortex (PFC) and is susceptible to age-related degeneration, suggesting that PFC homotopic connectivity is linked to changes in white-matter integrity. We investigated homotopic connectivity changes and whether these were associated with white-matter integrity in 338 individuals. In addition, we examined whether PFC homotopic FC was related to changes in the genu over 10 years and working memory over 5 years. There were increases and decreases in functional homotopy, with the former being prevalent in subcortical and frontal regions. Increased PFC homotopic FC was partially driven by structural degeneration and negatively associated with working memory, suggesting that it reflects detrimental age-related changes.

PMID: 32949903 [PubMed - as supplied by publisher]

Disturbance of thalamic metabolism and its association with regional neural dysfunction and cognitive impairment in minimal hepatic encephalopathy.

Sun, 09/20/2020 - 12:00
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Disturbance of thalamic metabolism and its association with regional neural dysfunction and cognitive impairment in minimal hepatic encephalopathy.

Eur J Radiol. 2020 Aug 29;131:109252

Authors: Chen LH, Shi JY, Zou TX, Zhang L, Gou Y, Lin Y, Chen HJ

Abstract
PURPOSE: To conduct the first investigation on thalamic metabolic alterations in minimal hepatic encephalopathy (MHE) and elucidate their association with intrinsic neural activity change and cognitive dysfunction.
METHODS: Thirty-eight cirrhotic patients [18 with MHE, 20 without MHE (NHE)] and 21 healthy controls (HC) were included, all of whom underwent 1H-magnetic resonance spectroscopy, resting-state functional magnetic resonance imaging (fMRI), as well as cognitive assessment based on the Psychometric Hepatic Encephalopathy Score (PHES). Metabolite ratios in the thalamus were measured, including N-acetyl aspartate (NAA)/creatine (Cr), glutamate plus glutamine (Glx)/Cr, choline (Cho)/Cr, and myo-inositol (mI)/Cr. Intrinsic neural activity was evaluated based on frequency-specific amplitude of low-frequency fluctuations (ALFF) using fMRI signals.
RESULTS: MHE patients showed an increase in Glx/Cr and a decrease in Cho/Cr and mI/Cr, compared with HC. These changes were aggravated from NHE to MHE. Cho/Cr and mI/Cr were positively correlated with regional ALFF derived from the frequency-specific band (0.01-0.027 Hz) and PHES. Receiver operating characteristic curve analysis showed that Cho/Cr and mI/Cr measurements exhibited moderate discrimination ability between NHE and MHE.
CONCLUSION: Our findings provide evidence that MHE is associated with disturbed metabolism in the thalamus, which may contribute to the altered neural activity and underlie the mechanisms of cognitive impairments. MRS measurements in the thalamus could serve as the potential biomarker for diagnosing MHE among cirrhotic patients.

PMID: 32949859 [PubMed - as supplied by publisher]

Dynamic time warping outperforms Pearson correlation in detecting atypical functional connectivity in autism spectrum disorders.

Sun, 09/20/2020 - 12:00
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Dynamic time warping outperforms Pearson correlation in detecting atypical functional connectivity in autism spectrum disorders.

Neuroimage. 2020 Sep 16;:117383

Authors: Linke AC, Mash LE, Fong CH, Kinnear MK, Kohli JS, Wilkinson M, Tung R, Keehn RJJ, Carper RA, Fishman I, Müller RA

Abstract
Resting state fMRI (rsfMRI) is frequently used to study brain function, including in clinical populations. Similarity of blood-oxygen-level-dependent (BOLD) fluctuations during rsfMRI between brain regions is thought to reflect intrinsic functional connectivity (FC), potentially due to history of coactivation. To quantify similarity, studies have almost exclusively relied on Pearson correlation, which assumes linearity and can therefore underestimate FC if the hemodynamic response function differs regionally or there is BOLD signal lag between timeseries. Here we show in three cohorts of children, adolescents and adults, with and without autism spectrum disorders (ASDs), that measuring the similarity of BOLD signal fluctuations using non-linear dynamic time warping (DTW) is more robust to global signal regression (GSR), has higher test-retest reliability and is more sensitive to task-related changes in FC. Additionally, when comparing FC between individuals with ASDs and typical controls, more group differences are detected using DTW. DTW estimates are also more related to ASD symptom severity and executive function, while Pearson correlation estimates of FC are more strongly associated with respiration during rsfMRI. Together these findings suggest that non-linear methods such as DTW improve estimation of resting state FC, particularly when studying clinical populations whose hemodynamics or neurovascular coupling may be altered compared to typical controls.

PMID: 32949710 [PubMed - as supplied by publisher]

Altered structure and functional connectivity of the hippocampus are associated with social and mathematical difficulties in nonverbal learning disability.

Sun, 09/20/2020 - 12:00
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Altered structure and functional connectivity of the hippocampus are associated with social and mathematical difficulties in nonverbal learning disability.

Hippocampus. 2020 Sep 19;:

Authors: Banker SM, Pagliaccio D, Ramphal B, Thomas L, Dranovsky A, Margolis AE

Abstract
The hippocampus is known to play a critical role in a variety of complex abilities, including visual-spatial reasoning, social functioning, and math. Nonverbal learning disability (NVLD) is a neurodevelopmental disorder characterized by deficits in visual-spatial reasoning that are accompanied by impairment in social function or mathematics, as well as motor or executive function skills. Despite the overlap between behaviors supported by the hippocampus and impairments in NVLD, the structure and function of the hippocampus in NVLD has not been studied. To address this gap in the literature, we first compared hippocampal volume and resting-state functional connectivity in children with NVLD (n = 24) and typically developing (TD) children (n = 20). We then explored associations between hippocampal structure, connectivity, and performance on measures of spatial, social, and mathematical ability. Relative to TD children, those with NVLD showed significant reductions in left hippocampal volume and greater hippocampal-cerebellar connectivity. In children with NVLD, reduced hippocampal volume associated with worse mathematical problem solving. Although children with NVLD exhibited more social problems (social responsiveness scale [SRS]) and higher hippocampal-cerebellar connectivity relative to TD children, greater connectivity was associated with fewer social problems among children with NVLD but not TD children. Such an effect may suggest a compensatory mechanism. These structural and functional alterations of the hippocampus may disrupt its putative role in organizing conceptual frameworks through cognitive mapping, thus contributing to the cross-domain difficulties that characterize NVLD.

PMID: 32949475 [PubMed - as supplied by publisher]

Structural and functional brain abnormalities in HIV disease revealed by multimodal MRI fusion: association with cognitive function.

Sun, 09/20/2020 - 12:00
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Structural and functional brain abnormalities in HIV disease revealed by multimodal MRI fusion: association with cognitive function.

Clin Infect Dis. 2020 Sep 18;:

Authors: Sui J, Li X, Bell RP, Towe SL, Gadde S, Chen NK, Meade CS

Abstract
BACKGROUND: HIV-associated neurocognitive impairment remains a prevalent comorbidity that impacts daily functioning and increases morbidity. While HIV infection is known to cause widespread disruptions in the brain, different MRI modalities have not been effectively integrated. This study applied 3-way supervised fusion to investigate how structural and functional co-alterations affect cognitive function.
METHODS: Participants (59 with HIV and 58 without HIV) completed comprehensive neuropsychological testing and multimodal MRI scanning to acquire high-resolution anatomical, diffusion-weighted, and resting-state functional images. Pre-processed data was reduced using voxel-based morphometry, probabilistic tractography, and regional homogeneity, respectively. We applied multimodal canonical correlation analysis with reference plus joint independent component analysis (MCCAR+jICA), using global cognitive functioning as the reference.
RESULTS: Compared to controls, participants with HIV had lower global cognitive functioning. One joint component was both group discriminating and correlated with cognitive function. This component included the following covarying regions: fractional anisotropy in the corpus callosum, short and long association fiber tracts, and corticopontine fibers; gray matter volume in thalamus, prefrontal cortex, precuneus, posterior parietal regions, and occipital lobe; and functional connectivity in fronto-parietal and visual processing regions. Component loadings for fractional anisotropy also correlated with immunosuppression.
CONCLUSIONS: These results suggest that co-alterations in brain structure and function can distinguish people with and without HIV and may drive cognitive impairment. As MRI becomes more commonplace in HIV care, multimodal fusion may provide neural biomarkers to support diagnosis and treatment of cognitive impairment.

PMID: 32948879 [PubMed - as supplied by publisher]

Aberrant functional connectivity in resting state networks of ADHD patients revealed by independent component analysis.

Sun, 09/20/2020 - 12:00
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Aberrant functional connectivity in resting state networks of ADHD patients revealed by independent component analysis.

BMC Neurosci. 2020 Sep 18;21(1):39

Authors: Zhang H, Zhao Y, Cao W, Cui D, Jiao Q, Lu W, Li H, Qiu J

Abstract
BACKGROUND: ADHD is one of the most common psychiatric disorders in children and adolescents. Altered functional connectivity has been associated with ADHD symptoms. This study aimed to investigate abnormal changes in the functional connectivity of resting-state brain networks (RSNs) among adolescent patients with different subtypes of ADHD.
METHODS: The data were obtained from the ADHD-200 Global Competition, including fMRI data from 88 ADHD patients (56 patients of ADHD-Combined, ADHD-C and 32 patients of ADHD-Inattentive, ADHD-I) and 67 typically developing controls (TD-C). Group ICA was utilized to research aberrant brain functional connectivity within the different subtypes of ADHD.
RESULTS: In comparison with the TD-C group, the ADHD-C group showed clusters of decreased functional connectivity in the left inferior occipital gyrus (p = 0.0041) and right superior occipital gyrus (p = 0.0011) of the dorsal attention network (DAN), supplementary motor area (p = 0.0036) of the executive control network (ECN), left supramarginal gyrus (p = 0.0081) of the salience network (SN), middle temporal gyrus (p = 0.0041), and superior medial frontal gyrus (p = 0.0055) of the default mode network (DMN), while the ADHD-I group showed decreased functional connectivity in the right superior parietal gyrus (p = 0.0017) of the DAN and left middle temporal gyrus (p = 0.0105) of the DMN. In comparison with the ADHD-I group, the ADHD-C group showed decreased functional connectivity in the superior temporal gyrus (p = 0.0062) of the AN, inferior temporal gyrus (p = 0.0016) of the DAN, and the dorsolateral superior frontal gyrus (p = 0.0082) of the DMN. All the clusters surviving at p < 0.05 (AlphaSim correction).
CONCLUSION: The results suggested that decreased functional connectivity within the DMN and DAN was responsible, at least in part, for the symptom of inattention in ADHD-I patients. Similarly, we believed that the impaired functional connectivity within networks may contribute to the manifestations of ADHD-C patients, including inattention, hyperactivity/impulsivity, and unconscious movements.

PMID: 32948139 [PubMed - as supplied by publisher]

Cortical midline structures associated with rumination in women with PTSD.

Fri, 09/18/2020 - 16:00
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Cortical midline structures associated with rumination in women with PTSD.

J Psychiatr Res. 2020 Sep 08;131:69-76

Authors: Philippi CL, Pessin S, Reyna L, Floyd T, Bruce SE

Abstract
Elevated rumination, characterized by repetitive, negative self-focused cognition, is common in posttraumatic stress disorder (PTSD) and has been shown to predict the onset and maintenance of the disorder. Neuroimaging research has implicated cortical midline brain structures, including the rostral anterior cingulate cortex (rACC), posterior cingulate cortex (PCC), and isthmus cingulate (IsthCing), in rumination in healthy and depressed populations. While past research has revealed dysfunction in cortical midline regions in PTSD, no studies have yet investigated the structural and functional neural mechanisms underlying rumination in women with PTSD. In the current study, we used structural MRI and resting-state fMRI to examine relationships between rumination and brain volume, as well as resting-state functional connectivity (rsFC) of cortical midline structures in women with PTSD due to interpersonal trauma (N = 71). We performed multiple linear regression analyses to relate brain volume in rACC, PCC, and IsthCing regions to self-reported rumination, after controlling for age and total intracranial volume. We also conducted standard seed-based voxelwise rsFC analyses for significant regions identified in the structural analysis. We found a significant relationship between greater rumination and volume in the left IsthCing (p = .025). Results from the rsFC analyses revealed a significant relationship between greater rumination and diminished rsFC between the left IsthCing and left precuneus (pFWE < .05). These findings provide novel support for alterations in the neural substrates of ruminative thought in women with PTSD. More broadly, we discuss clinical implications for targeted interventions to reduce rumination through psychotherapy or non-invasive brain stimulation.

PMID: 32942190 [PubMed - as supplied by publisher]

Predicting the fMRI Signal Fluctuation with Recurrent Neural Networks Trained on Vascular Network Dynamics.

Fri, 09/18/2020 - 16:00
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Predicting the fMRI Signal Fluctuation with Recurrent Neural Networks Trained on Vascular Network Dynamics.

Cereb Cortex. 2020 Sep 17;:

Authors: Sobczak F, He Y, Sejnowski TJ, Yu X

Abstract
Resting-state functional MRI (rs-fMRI) studies have revealed specific low-frequency hemodynamic signal fluctuations (<0.1 Hz) in the brain, which could be related to neuronal oscillations through the neurovascular coupling mechanism. Given the vascular origin of the fMRI signal, it remains challenging to separate the neural correlates of global rs-fMRI signal fluctuations from other confounding sources. However, the slow-oscillation detected from individual vessels by single-vessel fMRI presents strong correlation to neural oscillations. Here, we use recurrent neural networks (RNNs) to predict the future temporal evolution of the rs-fMRI slow oscillation from both rodent and human brains. The RNNs trained with vessel-specific rs-fMRI signals encode the unique brain oscillatory dynamic feature, presenting more effective prediction than the conventional autoregressive model. This RNN-based predictive modeling of rs-fMRI datasets from the Human Connectome Project (HCP) reveals brain state-specific characteristics, demonstrating an inverse relationship between the global rs-fMRI signal fluctuation with the internal default-mode network (DMN) correlation. The RNN prediction method presents a unique data-driven encoding scheme to specify potential brain state differences based on the global fMRI signal fluctuation, but not solely dependent on the global variance.

PMID: 32940658 [PubMed - as supplied by publisher]

Earlier onset of menstruation is related to increased body mass index in adulthood and altered functional correlations between visual, task control and somatosensory brain networks.

Fri, 09/18/2020 - 16:00
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Earlier onset of menstruation is related to increased body mass index in adulthood and altered functional correlations between visual, task control and somatosensory brain networks.

J Neuroendocrinol. 2020 Jul 12;:e12891

Authors: Shearrer GE, Sadler JR, Papantoni A, Burger KS

Abstract
Later onset of puberty has been associated with lower body mass index (BMI) in adulthood independent of childhood BMI. However, how the relationship between time of onset of puberty and BMI in adulthood is associated with neurocognitive outcomes is largely unstudied. In the present study, women were sampled from the Human Connectome Project 1200 parcellation, timeseries and netmats1 release (PTN) release. Inclusion criteria were: four (15 minutes) resting state fMRI scans, current measured BMI, self-reported age at onset of menstruation (a proxy of age at onset of puberty) and no endocrine complications (eg, polycystic ovarian syndrome). The effect of age at onset of menstruation, measured BMI at scan date and the interaction of age at onset of menstruation by BMI on brain functional correlation was modelled using fslnets (https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/FSLNets) controlling for race and age at scan. Corrected significance was set at a family-wise error probability (pFWE) < 0.05. A final sample of n = 510 (age 29.5 years ± 3.6, BMI at scan 25.9 ± 5.6 and age at onset of menstruation 12.7 ± 1.6 were included. Age at onset of menstruation was negatively associated with BMI at scan (r = - 0.19, P < 0.001). The interaction between age at onset of menstruation and BMI at scan was associated with stronger correlation between a somatosensory and visual network (t = 3.45, pFWE = 0.026) and a visual network and cingulo-opercular task control network (t = 4.74, pFWE = 0.0002). Post-hoc analyses of behavioural/cognitive measures showed no effect of the interaction between BMI and age at onset of menstruation on behavioural/cognitive measures. However, post-hoc analyses of heritability showed adult BMI and the correlation between the visual and somatosensory networks have high heritability. In sum, we report increased correlation between visual, taste-associated and self-control brain regions in women at high BMI with later age at onset of menstruation.

PMID: 32939874 [PubMed - as supplied by publisher]

Non-classical behavior of the default mode network regions during an information processing task.

Fri, 09/18/2020 - 16:00
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Non-classical behavior of the default mode network regions during an information processing task.

Brain Struct Funct. 2020 Sep 16;:

Authors: da Silva PHR, Rondinoni C, Leoni RF

Abstract
The default mode network (DMN) efficient deactivation and suppressed functional connectivity (FC) during goal-directed tasks, which require attentional resources, have been considered essential to healthy brain cognition. However, recent studies have shown that DMN regions do not always show the expected behavior. Then, we aimed to investigate the functional activation and connectivity of DMN nodes in young, healthy controls during a goal-directed task. We used an adaptation of the symbol digit modalities test (SDMT) to evaluate the information processing speed (IPS). Twenty-four subjects (10 women, age: 29 ± 7 years) underwent two functional Magnetic Resonance Imaging experiments: one during resting-state and one during a block-designed SDMT paradigm. We superimposed the templates of the DMN on the group activation map and observed the reorganization of the network. For the posterior cingulate cortex (PCC) node of the DMN, which is spatially extensive, comprising the precuneus (dorsal portion) and the posterior cingulate gyrus (PCG, ventral portion), the extent of each region was different between conditions, suggesting different functional roles for them. Therefore, for the functional connectivity (FC) analysis, we split the DMN-PCC region into two regions: left precuneus (BA 7) and PCG. The left precuneus (BA 7) was positively correlated with the left lingual gyrus (BA 17), a task-positive region, and negatively associated with the DMN nodes when comparing task performance with the resting-state condition. The other DMN regions presented the classical antagonistic role during the attentional task. In conclusion, we found that the activation and functional connectivity of the DMN is, in general, suppressed during the information processing. However, the left precuneus BA 7 presented a context-dependent modulatory behavior, working as a transient in-between hub connecting the DMN to task-positive areas. Such findings support studies that show increased activation and excitatory functional connectivity of DMN portions during goal-directed tasks. Moreover, our results may contribute to defining more precise functional correlates of IPS deficits in a wide range of clinical and neurological diseases.

PMID: 32939584 [PubMed - as supplied by publisher]

Classification of Non-Severe Traumatic Brain Injury from Resting-State EEG Signal Using LSTM Network with ECOC-SVM.

Fri, 09/18/2020 - 16:00
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Classification of Non-Severe Traumatic Brain Injury from Resting-State EEG Signal Using LSTM Network with ECOC-SVM.

Sensors (Basel). 2020 Sep 14;20(18):

Authors: Lai CQ, Ibrahim H, Abd Hamid AI, Abdullah JM

Abstract
Traumatic brain injury (TBI) is one of the common injuries when the human head receives an impact due to an accident or fall and is one of the most frequently submitted insurance claims. However, it is often always misused when individuals attempt an insurance fraud claim by providing false medical conditions. Therefore, there is a need for an instant brain condition classification system. This study presents a novel classification architecture that can classify non-severe TBI patients and healthy subjects employing resting-state electroencephalogram (EEG) as the input, solving the immobility issue of the computed tomography (CT) scan and magnetic resonance imaging (MRI). The proposed architecture makes use of long short term memory (LSTM) and error-correcting output coding support vector machine (ECOC-SVM) to perform multiclass classification. The pre-processed EEG time series are supplied to the network by each time step, where important information from the previous time step will be remembered by the LSTM cell. Activations from the LSTM cell is used to train an ECOC-SVM. The temporal advantages of the EEG were amplified and able to achieve a classification accuracy of 100%. The proposed method was compared to existing works in the literature, and it is shown that the proposed method is superior in terms of classification accuracy, sensitivity, specificity, and precision.

PMID: 32937801 [PubMed - in process]

More than just statics: Abnormal dynamic amplitude of low-frequency fluctuation in adolescent patients with pure conduct disorder.

Thu, 09/17/2020 - 21:00

More than just statics: Abnormal dynamic amplitude of low-frequency fluctuation in adolescent patients with pure conduct disorder.

J Psychiatr Res. 2020 Sep 01;131:60-68

Authors: Lu F, Liu P, Chen H, Wang M, Xu S, Yuan Z, Wang X, Wang S, Zhou J

Abstract
BACKGROUND: The human brain activity is inherently dynamic over time. Conventional neuroimaging studies have reported abnormalities of static intrinsic brain activity or connectivity in adolescent patients with conduct disorder (CD). Little is known, however, regarding the temporal dynamics alterations of brain activity in CD.
METHODS: In this study, resting-state functional magnetic resonance imaging examinations were performed on adolescent patients with pure CD and age-matched typically developing (TD) controls. The dynamic amplitude of low-frequency fluctuation (dALFF) was first measured using a sliding-window method. The temporal variability (TV) was then quantified as the variance of dALFF over time and compared between the two groups. Further, the relationships between aberrant TV of dALFF and clinical features were evaluated.
RESULTS: CD patients showed reduced brain dynamics (less temporal variability) in the default-mode network, frontal-limbic cortices, sensorimotor areas, and visual regions which are involved in cognitive, emotional and perceptional processes. Importantly, receiver operating characteristic curve analysis revealed that regions with altered TV of dALFF exhibited a better ability to distinguish CD patients than the results from static ALFF in the current data set.
CONCLUSIONS: Our findings extended previous work by providing a novel perspective on the neural mechanisms underlying adolescent patients with CD and demonstrated that the altered dynamic local brain activity may be a potential biomarker for CD diagnosis.

PMID: 32937251 [PubMed - as supplied by publisher]

Graph theory application with functional connectivity to distinguish left from right temporal lobe epilepsy.

Thu, 09/17/2020 - 21:00

Graph theory application with functional connectivity to distinguish left from right temporal lobe epilepsy.

Epilepsy Res. 2020 Sep 06;167:106449

Authors: Amiri S, Mehvari-Habibabadi J, Mohammadi-Mobarakeh N, Hashemi-Fesharaki SS, Mirbagheri MM, Elisevich K, Nazem-Zadeh MR

Abstract
OBJECTIVE: To investigate the application of graph theory with functional connectivity to distinguish left from right temporal lobe epilepsy (TLE).
METHODS: Alterations in functional connectivity within several brain networks - default mode (DMN), attention (AN), limbic (LN), sensorimotor (SMN) and visual (VN) - were examined using resting-state functional MRI (rs-fMRI). The study accrued 21 left and 14 right TLE as well as 17 nonepileptic control subjects. The local nodal degree, a feature of graph theory, was calculated foreach of the brain networks. Multivariate logistic regression analysis was performed to determine the accuracy of identifying seizure laterality based on significant differences in local nodal degree in the selected networks.
RESULTS: Left and right TLE patients showed dissimilar patterns of alteration in functional connectivity when compared to control subjects. Compared with right TLE, patients with left TLE exhibited greater nodal degree' (i.e. hyperconnectivity) with right superomedial frontal gyrus (in DMN), inferior frontal gyrus pars triangularis (in AN), right caudate and left superior temporal gyrus (in LN) and left paracentral lobule (in SMN), while showing lesser nodal degree (i.e. hypoconnectivity) with left temporal pole (in DMN), right insula (in LN), left supplementary motor area (in SMN), and left fusiform gyrus (in VN). The LN showed the highest accuracy of 82.9% among all considered networks in determining laterality of the TLE. By combinations of local degree attributes in the DMN, AN, LN, and VN, logistic regression analysis demonstrated an accuracy of 94.3% by comparison.
CONCLUSION: Our study demonstrates the utility of graph theory application to brain network analysis as a potential biomarker to assist in the determination of TLE laterality and improve the confidence in presurgical decision-making in cases of TLE.

PMID: 32937221 [PubMed - as supplied by publisher]

Subarachnoid hemorrhage leads to early and persistent functional connectivity and behavioral changes in mice.

Thu, 09/17/2020 - 21:00
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Subarachnoid hemorrhage leads to early and persistent functional connectivity and behavioral changes in mice.

J Cereb Blood Flow Metab. 2020 Sep 16;:271678X20940152

Authors: Chung DY, Oka F, Jin G, Harriott A, Kura S, Aykan SA, Qin T, Iii WJE, Lee H, Yaseen MA, Sakadžić S, Boas DA, Whalen MJ, Ayata C

Abstract
Aneurysmal subarachnoid hemorrhage (SAH) leads to significant long-term cognitive deficits, which can be associated with alterations in resting state functional connectivity (RSFC). However, modalities such as fMRI-which is commonly used to assess RSFC in humans-have practical limitations in small animals. Therefore, we used non-invasive optical intrinsic signal imaging to determine the effect of SAH on RSFC in mice up to three months after prechiasmatic blood injection. We assessed Morris water maze (MWM), open field test (OFT), Y-maze, and rotarod performance from approximately two weeks to three months after SAH. Compared to sham, we found that SAH reduced motor, retrosplenial, and visual seed-based connectivity indices. These deficits persisted in retrosplenial and visual cortex seeds at three months. Seed-to-seed analysis confirmed early attenuation of correlation coefficients in SAH mice, which persisted in predominantly posterior network connections at later time points. Seed-independent global and interhemispheric indices of connectivity revealed decreased correlations following SAH for at least one month. SAH led to MWM hidden platform and OFT deficits at two weeks, and Y-maze deficits for at least three months, without altering rotarod performance. In conclusion, experimental SAH leads to early and persistent alterations both in hemodynamically derived measures of RSFC and in cognitive performance.

PMID: 32936728 [PubMed - as supplied by publisher]

Altered long- and short-range functional connectivity density associated with poor sleep quality in patients with chronic insomnia disorder: A resting-state fMRI study.

Thu, 09/17/2020 - 21:00
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Altered long- and short-range functional connectivity density associated with poor sleep quality in patients with chronic insomnia disorder: A resting-state fMRI study.

Brain Behav. 2020 Sep 16;:e01844

Authors: Zhou F, Zhu Y, Zhu Y, Huang M, Jiang J, He L, Huang S, Zeng X, Gong H

Abstract
INTRODUCTION: Previous neuroimaging studies have suggested that brain functional impairment and hyperarousal occur during the daytime among patients with chronic insomnia disorder (CID); however, alterations to the brain's intrinsic functional architecture and their association with sleep quality have not yet been documented.
METHODS: In this study, our aim was to investigate the insomnia-related alterations to the intrinsic connectome in patients with CID (n = 27) at resting state, with a data-driven approach based on graph theory assessment and functional connectivity density (FCD), which can be interpreted as short-range (intraregional) or long-range (interregional) mapping.
RESULTS: Compared with healthy controls with good sleep, CID patients showed significantly decreased long-range FCD in the dorsolateral prefrontal cortices and the putamen. These patients also showed decreased short-range FCD in their multimodal-processing regions, executive control network, and supplementary motor-related areas. Furthermore, several regions showed increased short-range FCD in patients with CID, implying hyper-homogeneity of local activity.
CONCLUSIONS: Together, these findings suggest that insufficient sleep during chronic insomnia widely affects cortical functional activities, including disrupted FCD and increased short-range FCD, which is associated with poor sleep quality.

PMID: 32935924 [PubMed - as supplied by publisher]

Resting-State Fluctuations Underlie Free and Creative Verbal Behaviors in the Human Brain.

Thu, 09/17/2020 - 21:00
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Resting-State Fluctuations Underlie Free and Creative Verbal Behaviors in the Human Brain.

Cereb Cortex. 2020 Sep 16;:

Authors: Broday-Dvir R, Malach R

Abstract
Resting-state fluctuations are ubiquitous and widely studied phenomena of the human brain, yet we are largely in the dark regarding their function in human cognition. Here we examined the hypothesis that resting-state fluctuations underlie the generation of free and creative human behaviors. In our experiment, participants were asked to perform three voluntary verbal tasks: a verbal fluency task, a verbal creativity task, and a divergent thinking task, during functional magnetic resonance imaging scanning. Blood oxygenation level dependent (BOLD)-activity during these tasks was contrasted with a control- deterministic verbal task, in which the behavior was fully determined by external stimuli. Our results reveal that all voluntary verbal-generation responses displayed a gradual anticipatory buildup that preceded the deterministic control-related responses. Critically, the time-frequency dynamics of these anticipatory buildups were significantly correlated with resting-state fluctuations' dynamics. These correlations were not a general BOLD-related or verbal-response related result, as they were not found during the externally determined verbal control condition. Furthermore, they were located in brain regions known to be involved in language production, specifically the left inferior frontal gyrus. These results suggest a common function of resting-state fluctuations as the neural mechanism underlying the generation of free and creative behaviors in the human cortex.

PMID: 32935840 [PubMed - as supplied by publisher]

A NOVEL SPATIO-TEMPORAL HUB IDENTIFICATION METHOD FOR DYNAMIC FUNCTIONAL NETWORKS.

Thu, 09/17/2020 - 21:00
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A NOVEL SPATIO-TEMPORAL HUB IDENTIFICATION METHOD FOR DYNAMIC FUNCTIONAL NETWORKS.

Proc IEEE Int Symp Biomed Imaging. 2020 Apr;2020:1416-1419

Authors: Chen A, Yang D, Yan C, Peng Z, Kim M, Laurienti PJ, Wu G

Abstract
Functional connectivity (FC) has been widely investigated to understand the cognition and behavior that emerge from human brain. Recently, there is overwhelming evidence showing that quantifying temporal changes in FC may provide greater insight into fundamental properties of brain network. However, scant attentions has been given to characterize the functional dynamics of network organization. To address this challenge, we propose a novel spatio-temporal hub identification method for functional brain networks by simultaneously identifying hub nodes in each static sliding window and maintaining the reasonable dynamics across the sliding windows, which allows us to further characterize the full-spectrum evolution of hub nodes along with the subject-specific functional dynamics. We have evaluated our spatio-temporal hub identification method on resting-state functional resonance imaging (fMRI) data from an obsessive-compulsive disease (OCD) study, where our new functional hub detection method outperforms current methods (without considering functional dynamics) in terms of accuracy and consistency.

PMID: 32934768 [PubMed]

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