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BOLD fMRI

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https://www.readbyqxmd.com/read/28227771/tracking-intrinsic-connectivity-brain-network-features-during-successive-pseudo-resting-states-and-interoceptive-task-fmri
#1
Behnaz Jarrahi, Dante Mantini, Behnaz Jarrahi, Dante Mantini, Behnaz Jarrahi, Dante Mantini
Advanced multivariate analyses of functional magnetic resonance imaging (fMRI) data based on blood oxygen level-dependent (BOLD) contras have revealed that the human brain organizes its activities into multiple intrinsic connectivity networks (ICNs). Several fMRI studies have evaluated the modulations of these networks during different cognitive or emotional tasks using blind source separation techniques particularly the independent component analysis (ICA). In this exploratory study, we applied ICA methodology to examine ICN modulations under different interoceptive conditions...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227770/randomness-in-resting-state-functional-connectivity-matrices
#2
Victor M Vergara, Vince Calhoun, Victor M Vergara, Vince Calhoun, Vince Calhoun, Victor M Vergara
Separate brain regions exhibit synchronous intrinsic activity used to assess connectivity patterns known to appear among brain areas. Connectivity is evaluated from functional magnetic resonance imaging (fMRI) measuring the blood oxygen level dependent signal (BOLD) signal. Extensive research has revealed a distinctive pattern of connectivity among brain areas that can be visualized through a functional connectivity matrix (FCM) matrix. As in any measurement, BOLD signals are subject to contamination from noise and nuisances unrelated to brain's intrinsic activity...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227769/identifying-the-effects-of-visceral-interoception-on-human-brain-connectome-a-multivariate-analysis-of-covariance-of-fmri-data
#3
Behnaz Jarrahi, Dante Mantini, Behnaz Jarrahi, Dante Mantini, Behnaz Jarrahi, Dante Mantini
Sources of variations in the neural circuitry of the human brain and interrelationship between intrinsic connectivity networks (ICNs) are still a matter of debate and ongoing research. Here, we applied a multivariate analysis of covariance (MANCOVA) based on high-dimensional independent component analysis (ICA) to identify the effects of interoception and related variables on human brain connectome. Fifteen healthy right-handed subjects (all females, age range 21 - 48 years; mean age = 30.3, SD = 8.7 years) underwent a blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) that included continuous intravesical saline infusion and drainage...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227749/reconstructing-multivariate-causal-structure-between-functional-brain-networks-through-a-laguerre-volterra-based-granger-causality-approach
#4
Andrea Duggento, Gaetano Valenza, Luca Passamonti, Maria Guerrisi, Riccardo Barbieri, Nicola Toschi, Andrea Duggento, Gaetano Valenza, Luca Passamonti, Maria Guerrisi, Riccardo Barbieri, Nicola Toschi, Andrea Duggento, Nicola Toschi, Maria Guerrisi, Luca Passamonti, Riccardo Barbieri, Gaetano Valenza
Classical multivariate approaches based on Granger causality (GC) which estimate functional connectivity in the brain are almost exclusively based on autoregressive models. Nevertheless, information available from past samples is limited due to both signal autocorrelation and necessarily low model orders. Consequently, multiple time-scales interactions are usually unaccounted for. To overcome these limitations, in this study we propose the use of discrete-time orthogonal Laguerre basis functions within a Wiener-Volterra decomposition of the BOLD signals to perform effective GC assessments of brain functional connectivity...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226851/transcranial-focused-ultrasound-for-bold-fmri-signal-modulation-in-humans
#5
Leo Ai, Jerel K Mueller, Andrea Grant, Yigitcan Eryaman, Wynn Legon, Leo Ai, Jerel K Mueller, Andrea Grant, Yigitcan Eryaman, Wynn Legon, Andrea Grant, Wynn Legon, Yigitcan Eryaman, Leo Ai, Jerel K Mueller
Transcranial focused ultrasound (tFUS) is an emerging form of non-surgical human neuromodulation that confers advantages over existing electro and electromagnetic technologies by providing a superior spatial resolution on the millimeter scale as well as the capability to target sub-cortical structures non-invasively. An examination of the pairing of tFUS and blood oxygen level dependent (BOLD) functional MRI (fMRI) in humans is presented here.
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226702/estimation-of-voxel-wise-dynamic-cerebrovascular-reactivity-curves-from-resting-state-fmri-data
#6
Prokopis C Prokopiou, Kevin Murphy, Richard G Wise, Georgios D Mitsis, Prokopis C Prokopiou, Kevin Murphy, Richard G Wise, Georgios D Mitsis, Prokopis C Prokopiou, Georgios D Mitsis, Richard G Wise, Kevin Murphy
In this work, we investigate the linear dynamic interactions between fluctuations in arterial CO2 that occur during normal breathing, and the BOLD fMRI signal. We cast this problem within a systems-theoretic framework, where we employ functional expansions for the estimation of the impulse responses in large regions of interest, as well as in individual voxels. We also implement classification schemes in order to identify different brain regions with similar cerebrovascular reactivity characteristics. Our results reveal that it is feasible to obtain reliable estimates of cerebrovascular reactivity curves from resting-state data and that these curves exhibit considerable variability across different brain regions that may be related to the underlying anatomy...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226438/multiscale-network-activity-in-resting-state-fmri
#7
Shella D Keilholz, Jacob C W Billings, Kai Wang, Anzar Abbas, Claudia Hafeneger, Wen-Ju Pan, Sadia Shakil, Maysam Nezafati, Shella D Keilholz, Jacob C W Billings, Kai Wang, Anzar Abbas, Claudia Hafeneger, Wen-Ju Pan, Sadia Shakil, Maysam Nezafati, Claudia Hafeneger, Anzar Abbas, Kai Wang, Sadia Shakil, Jacob C W Billings, Shella D Keilholz, Maysam Nezafati, Wen-Ju Pan
The brain is inherently multiscalar in both space and time. We argue that this multiscalar nature is reflected in the blood oxygenation level dependent (BOLD) fluctuations used to map functional connectivity. We present evidence that global fluctuations in activity, quasiperiodic spatiotemporal patterns, and aperiodic time-varying activity coexist within the BOLD signal. These processes can be separated using careful analysis and appear to reflect electrical activity on similar scales, suggesting that the BOLD signal fluctuations can provide novel insight into the functional architecture of the brain...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226437/exploring-spatiotemporal-dynamics-of-the-human-brain-by-multimodal-imaging
#8
Han Yuan, Jerzy Bodurka, Lei Ding, Han Yuan, Jerzy Bodurka, Lei Ding, Han Yuan, Lei Ding, Jerzy Bodurka
Functional magnetic resonance imaging (fMRI) studies utilizing measures of hemodynamic signal, such as the blood-oxygenation-level dependent (BOLD) signal, have discovered that resting-state brain activities are organized into multiple large-scale functional networks, coined as resting state networks (RSNs). However, an important limitation of the available fMRI studies is that hemodynamic signals only provide an indirect measure of neuronal activity and that the neurobiological basis of the fMRI RSNs is not clear...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226417/an-efficient-multi-stage-algorithm-for-full-calibration-of-the-hemodynamic-model-from-bold-signal-responses
#9
Brian Zambri, Rabia Djellouli, Meriem Laleg-Kirati
We propose a computational strategy that falls into the category of prediction/correction iterative-type approaches, for calibrating the hemodynamic model introduced by Friston et al. (2000). The proposed method is employed to estimate consecutively the values of the biophysiological system parameters and the external stimulus characteristics of the model. Numerical results corresponding to both synthetic and real functional Magnetic Resonance Imaging (fMRI) measurements for a single stimulus as well as for multiple stimuli are reported to highlight the capability of this computational methodology to fully calibrate the considered hemodynamic model...
February 22, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28223811/risk-assessment-of-aggressive-behavior-in-chinese-patients-with-schizophrenia-by-fmri-and-comt-gene
#10
Xiaoli Tang, Jun Jin, Yi Tang, Jinbo Cao, Junjie Huang
BACKGROUND: Blood-oxygen-level dependent functional magnetic resonance imaging (BOLD-fMRI) maps cerebral activity by the hemodynamic response. Catechol-O-methyltransferase (COMT) gene is involved in the metabolism of dopamine. It is reported that both of these can be used to assess the aggression risk in patients with schizophrenia. However, these methods to assess the aggression risk patients with schizophrenia have not been established in China. Therefore, we deliver here a systematic review and meta-analysis based on the studies dealing with Chinese patients...
2017: Neuropsychiatric Disease and Treatment
https://www.readbyqxmd.com/read/28223034/children-s-head-motion-during-fmri-tasks-is-heritable-and-stable-over-time
#11
Laura E Engelhardt, Mary Abbe Roe, Jenifer Juranek, Dana DeMaster, K Paige Harden, Elliot M Tucker-Drob, Jessica A Church
Head motion during fMRI scans negatively impacts data quality, and as post-acquisition techniques for addressing motion become increasingly stringent, data retention decreases. Studies conducted with adult participants suggest that movement acts as a relatively stable, heritable phenotype that serves as a marker for other genetically influenced phenotypes. Whether these patterns extend downward to childhood has critical implications for the interpretation and generalizability of fMRI data acquired from children...
February 1, 2017: Developmental Cognitive Neuroscience
https://www.readbyqxmd.com/read/28221328/retinotopic-fmri-reveals-visual-dysfunction-and-functional-reorganization-in-the-visual-cortex-of-mild-to-moderate-glaucoma-patients
#12
Wei Zhou, Eric R Muir, Kundandeep S Nagi, Steven Chalfin, Pavel Rodriguez, Timothy Q Duong
PURPOSE: To investigate retinotopic functional representation in the visual cortex of mild to moderate primary open-angle glaucoma (POAG) participants and age-matched normal volunteers using high-resolution retinotopic blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI). METHODS: fMRI was performed on 9 POAG participants (61±11 y old) and 9 age-matched controls (58±5 y old) were studied. A wide-view visual presentation (±55 degrees) was used to evaluate central and peripheral vision...
February 17, 2017: Journal of Glaucoma
https://www.readbyqxmd.com/read/28219776/deactivation-in-the-posterior-mid-cingulate-cortex-reflects-perceptual-transitions-during-binocular-rivalry-evidence-from-simultaneous-eeg-fmri
#13
Abhrajeet Roy, Keith Jamison, Sheng He, Steve Engel, Bin He
Binocular rivalry is a phenomenon in which perception spontaneously shifts between two different images that are dichoptically presented to the viewer. By elucidating the cortical networks responsible for these stochastic fluctuations in perception, we can potentially learn much about the neural correlates of visual awareness. We obtained concurrent EEG-fMRI data for a group of 20 healthy human subjects during the continuous presentation of dichoptic visual stimuli. The two eyes' images were tagged with different temporal frequencies so that eye specific steady-state visual evoked potential (SSVEP) signals could be extracted from the EEG data for direct comparison with changes in fMRI BOLD activity associated with binocular rivalry...
February 17, 2017: NeuroImage
https://www.readbyqxmd.com/read/28213112/laminar-imaging-of-positive-and-negative-bold-in-human-visual-cortex-at-7t
#14
Alessio Fracasso, Peter R Luijten, Serge O Dumoulin, Natalia Petridou
Deciphering the direction of information flow is critical to understand the brain. Data from non-human primate histology shows that connections between lower to higher areas (e.g. retina→V1), and between higher to lower areas (e.g. V1←V2) can be dissociated based upon the distribution of afferent synapses at the laminar level. Ultra-high field scanners opened up the possibility to image brain structure and function at an unprecedented level of detail. Taking advantage of the increased spatial resolution available, it could theoretically be possible to disentangle activity from different cortical depths from human cerebral cortex, separately studying different compartments across depth...
February 14, 2017: NeuroImage
https://www.readbyqxmd.com/read/28208069/neural-activity-during-production-of-rorschach-responses-an-fmri-study
#15
Luciano Giromini, Donald J Viglione, Alessandro Zennaro, Franco Cauda
Recently, a lot of effort has been made to ground Rorschach interpretations to their evidence base. To date, however, no studies have yet described, via fMRI, what brain areas get involved when one takes the Rorschach. To fill this gap in the literature, we administered the ten-inkblot stimuli to 26 healthy volunteers during fMRI. Analysis of BOLD signals revealed that, compared to fixating a cross, looking at the Rorschach inkblots while thinking of what they might be associated with higher temporo-occipital and fronto-parietal activations, and with greater activity in some small, sub-cortical regions included in the limbic system...
February 10, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/28207389/an-efficient-reconstruction-algorithm-based-on-the-alternating-direction-method-of-multipliers-for-joint-estimation-of-r2-and-off-resonance-in-fmri
#16
Chenxi Hu, Stanley Reeves, Dana Peters, Donald Twieg
R 2 mapping is a useful tool in blood-oxygen-level dependent (BOLD) fMRI due to its quantitative nature. However, like T 2 -weighted imaging, standard R 2 mapping based on multiecho EPI suffers from geometric distortion, due to strong offresonance near the air-tissue interface. Joint mapping of R 2 and off-resonance can correct the geometric distortion and is less susceptible to motion artifacts. Single-shot joint mapping of R 2 and off-resonance is possible with a rosette trajectory due to its frequent sampling of the k-space center...
February 13, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28203153/bold-independent-computational-entropy-assesses-functional-donut-like-structures-in-brain-fmri-images
#17
James F Peters, Sheela Ramanna, Arturo Tozzi, Ebubekir İnan
We introduce a novel method for the measurement of information level in fMRI (functional Magnetic Resonance Imaging) neural data sets, based on image subdivision in small polygons equipped with different entropic content. We show how this method, called maximal nucleus clustering (MNC), is a novel, fast and inexpensive image-analysis technique, independent from the standard blood-oxygen-level dependent signals. MNC facilitates the objective detection of hidden temporal patterns of entropy/information in zones of fMRI images generally not taken into account by the subjective standpoint of the observer...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28198067/verbal-spatial-iq-discrepancies-impact-brain-activation-associated-with-the-resolution-of-cognitive-conflict-in-children-and-adolescents
#18
Amy E Margolis, Katie S Davis, Lisa S Pao, Amy Lewis, Xiao Yang, Gregory Tau, Guihu Zhao, Zhishun Wang, Rachel Marsh
Verbal-spatial discrepancies are common in healthy individuals and in those with neurodevelopmental disorders associated with cognitive control deficits including: Autism Spectrum Disorder, Non-Verbal Learning Disability, Fragile X, 22q11 deletion, and Turner Syndrome. Previous data from healthy individuals suggest that the magnitude of the difference between verbal IQ (VIQ) and performance IQ (PIQ) scores (the VIQ>PIQ discrepancy) is associated with reduced thickness in frontal and parietal cortices (inferior frontal, anterior cingulate, inferior parietal lobule, and supramarginal gyrus) that support cognitive control...
February 15, 2017: Developmental Science
https://www.readbyqxmd.com/read/28197105/investigating-the-role-of-glutamate-and-gaba-in-the-modulation-of-transthalamic-activity-a-combined-fmri-fmrs-study
#19
Nathalie Just, Sarah Sonnay
The Excitatory-Inhibitory balance (EIB) between glutamatergic and GABAergic neurons is known to regulate the function of thalamocortical neurocircuits. The thalamus is known as an important relay for glutamatergic and GABAergic signals ascending/descending to/from the somatosensory cortex in rodents. However, new investigations attribute a larger role to thalamic nuclei as modulators of information processing within the cortex. In this study, functional Magnetic Resonance Spectroscopy (fMRS) was used to measure glutamate (Glu) and GABA associations with BOLD responses during activation of the thalamus to barrel cortex (S1BF) pathway at 9...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28190516/changes-in-the-correlation-between-spatial-and-temporal-source-memory-performance-and-bold-activity-across-the-adult-lifespan
#20
E Ankudowich, S Pasvanis, M N Rajah
Studies investigating age-related functional differences associated with source memory have recently focused on the importance of clarifying the relationship between effects of age and performance on memory-related brain activations. One methodological challenge has been in discriminating between effects of age on memory-related brain activations that are independent from age-related differences in performance. In the current study, event-related functional magnetic resonance imaging (fMRI) was used to identify brain activity during spatial and temporal source encoding and retrieval across the adult lifespan...
January 12, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
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