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https://www.readbyqxmd.com/read/29226283/improving-functional-mri-registration-using-whole-brain-functional-correlation-tensors
#1
Yujia Zhou, Pew-Thian Yap, Han Zhang, Lichi Zhang, Qianjin Feng, Dinggang Shen
Population studies of brain function with resting-state functional magnetic resonance imaging (rs-fMRI) largely rely on the accurate inter-subject registration of functional areas. This is typically achieved through registration of the corresponding T1-weighted MR images with more structural details. However, accumulating evidence has suggested that such strategy cannot well-align functional regions which are not necessarily confined by the anatomical boundaries defined by the T1-weighted MR images. To mitigate this problem, various registration algorithms based directly on rs-fMRI data have been developed, most of which have utilized functional connectivity (FC) as features for registration...
September 2017: Medical Image Computing and Computer-assisted Intervention: MICCAI ..
https://www.readbyqxmd.com/read/29205291/interactive-effects-of-seizure-frequency-and-lateralization-on-intratemporal-effective-connectivity-in-temporal-lobe-epilepsy
#2
Chang-Hyun Park, Yun Seo Choi, Hyeon Jin Kim, Hwa-Kyung Chung, A-Reum Jung, Jeong Hyun Yoo, Hyang Woon Lee
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...
December 4, 2017: Epilepsia
https://www.readbyqxmd.com/read/29204807/analysis-of-fmri-data-using-noise-diffusion-network-models-a-new-covariance-coding-perspective
#3
Matthieu Gilson
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...
December 4, 2017: Biological Cybernetics
https://www.readbyqxmd.com/read/29196319/object-representations-in-human-visual-cortex-formed-through-temporal-integration-of-dynamic-partial-shape-views
#4
Tanya Orlov, Ehud Zohary
We typically recognize visual objects, by utilizing the spatial layout of their parts, simultaneously present on the retina. Thus, shape extraction is based on integration of the relevant retinal information over space. The lateral occipital complex (LOC) can faithfully represent shape in such conditions. However, sometimes, integration over time is required to determine object shape. To study shape extraction through temporal integration of successive partial-shape views, we presented human participants (both men and women) with artificial shapes that moved behind a narrow vertical or horizontal slit...
December 1, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29187817/predicting-long-term-cognitive-outcome-following-breast-cancer-with-pre-treatment-resting-state-fmri-and-random-forest-machine-learning
#5
Shelli R Kesler, Arvind Rao, Douglas W Blayney, Ingrid A Oakley-Girvan, Meghan Karuturi, Oxana Palesh
We aimed to determine if resting state functional magnetic resonance imaging (fMRI) acquired at pre-treatment baseline could accurately predict breast cancer-related cognitive impairment at long-term follow-up. We evaluated 31 patients with breast cancer (age 34-65) prior to any treatment, post-chemotherapy and 1 year later. Cognitive testing scores were normalized based on data obtained from 43 healthy female controls and then used to categorize patients as impaired or not based on longitudinal changes. We measured clustering coefficient, a measure of local connectivity, by applying graph theory to baseline resting state fMRI and entered these metrics along with relevant patient-related and medical variables into random forest classification...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/29186345/organizational-principles-of-abstract-words-in-the-human-brain
#6
Xiaosha Wang, Wei Wu, Zhenhua Ling, Yangwen Xu, Yuxing Fang, Xiaoying Wang, Jeffrey R Binder, Weiwei Men, Jia-Hong Gao, Yanchao Bi
words constitute nearly half of the human lexicon and are critically associated with human abstract thoughts, yet little is known about how they are represented in the brain. We tested the neural basis of 2 classical cognitive notions of abstract meaning representation: by linguistic contexts and by semantic features. We collected fMRI BOLD responses for 360 abstract words and built theoretical representational models from state-of-the-art corpus-based natural language processing models and behavioral ratings of semantic features...
November 23, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/29185805/an-optimized-method-for-bayesian-connectivity-change-point-model
#7
Xiuchun Xiao, Bing Liu, Jing Zhang, Xueli Xiao, Yi Pan
The brain undergoes functional dynamic changes at all times. Investigating functional dynamics has been recently verified to be helpful for detecting psychological conditions and powerful for analyzing disease-related abnormalities of the brain. This article aims to detect functional dynamics. Specifically, we focus on how to effectively distinguish corresponding functional connectivity and change points from functional magnetic resonance imaging (fMRI) data. By combining Bayesian connectivity change point model (BCCPM), a modified genetic algorithm (GA) is presented to optimize the evolutionary procedure toward the most probable distributions of real change points in fMRI...
November 29, 2017: Journal of Computational Biology: a Journal of Computational Molecular Cell Biology
https://www.readbyqxmd.com/read/29176647/mri-simulation-study-investigating-effects-of-vessel-topology-diffusion-and-susceptibility-on-transverse-relaxation-rates-using-a-cylinder-fork-model
#8
Mohammed Salman Shazeeb, Jayashree Kalpathy-Cramer, Bashar Issa
Brain vasculature is conventionally represented as straight cylinders when simulating blood oxygenation level dependent (BOLD) contrast effects in functional magnetic resonance imaging (fMRI). In reality, the vasculature is more complicated with branching and coiling especially in tumors. Diffusion and susceptibility changes can also introduce variations in the relaxation mechanisms within tumors. This study introduces a simple cylinder fork model (CFM) and investigates the effects of vessel topology, diffusion, and susceptibility on the transverse relaxation rates R2* and R2...
November 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29170853/brain-networks-are-independently-modulated-by-donepezil-sleep-and-sleep-deprivation
#9
Jonathan Wirsich, Marc Rey, Maxime Guye, Christian Bénar, Laura Lanteaume, Ben Ridley, Sylviane Confort-Gouny, Catherine Cassé-Perrot, Elisabeth Soulier, Patrick Viout, Franck Rouby, Marie-Noëlle Lefebvre, Christine Audebert, Romain Truillet, Elisabeth Jouve, Pierre Payoux, David Bartrés-Faz, Régis Bordet, Jill C Richardson, Claudio Babiloni, Paolo Maria Rossini, Joelle Micallef, Olivier Blin, Jean-Philippe Ranjeva
Resting-state connectivity has been widely studied in the healthy and pathological brain. Less well-characterized are the brain networks altered during pharmacological interventions and their possible interaction with vigilance. In the hopes of finding new biomarkers which can be used to identify cortical activity and cognitive processes linked to the effects of drugs to treat neurodegenerative diseases such as Alzheimer's disease, the analysis of networks altered by medication would be particularly interesting...
November 23, 2017: Brain Topography
https://www.readbyqxmd.com/read/29167478/an-evolutionary-game-theory-model-of-spontaneous-brain-functioning
#10
Dario Madeo, Agostino Talarico, Alvaro Pascual-Leone, Chiara Mocenni, Emiliano Santarnecchi
Our brain is a complex system of interconnected regions spontaneously organized into distinct networks. The integration of information between and within these networks is a continuous process that can be observed even when the brain is at rest, i.e. not engaged in any particular task. Moreover, such spontaneous dynamics show predictive value over individual cognitive profile and constitute a potential marker in neurological and psychiatric conditions, making its understanding of fundamental importance in modern neuroscience...
November 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29162176/a-neurocomputational-investigation-of-reinforcement-based-decision-making-as-a-candidate-latent-vulnerability-mechanism-in-maltreated-children
#11
Mattia I Gerin, Vanessa B Puetz, R James R Blair, Stuart White, Arjun Sethi, Ferdinand Hoffmann, Amy L Palmer, Essi Viding, Eamon J McCrory
Alterations in reinforcement-based decision making may be associated with increased psychiatric vulnerability in children who have experienced maltreatment. A probabilistic passive avoidance task and a model-based functional magnetic resonance imaging analytic approach were implemented to assess the neurocomputational components underlying decision making: (a) reinforcement expectancies (the representation of the outcomes associated with a stimulus) and (b) prediction error signaling (the ability to detect the differences between expected and actual outcomes)...
December 2017: Development and Psychopathology
https://www.readbyqxmd.com/read/29161884/accounting-for-non-gaussian-sources-of-spatial-correlation-in-parametric-fmri-paradigms-ii-a-method-to-obtain-first-level-analysis-residuals-with-uniform-and-gaussian-spatial-autocorrelation-function-and-independent-and-identically-distributed-time-series
#12
Kaundinya Gopinath, Venkatagiri Krishnamurthy, Simon Lacey, K Sathian
A recent study (Eklund et al., 2016) has shown that cluster-wise family-wise error (FWE) rate corrected inferences made in parametric statistical methods based fMRI studies over the past couple of decades may have been invalid, particularly for cluster defining thresholds less stringent than p < 0.001; principally because the spatial autocorrelation functions (sACF) of fMRI data had been modeled incorrectly to follow a Gaussian form, whereas empirical data suggests otherwise (Eklund et al., 2016). Hence the residuals from general linear model (GLM) based fMRI activation estimates in these studies may not have possessed a homogenously Gaussian sACF (Eklund et al...
November 22, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/29160930/brain-responses-to-social-norms-meta-analyses-of-fmri-studies
#13
Oksana Zinchenko, Marie Arsalidou
Social norms have a critical role in everyday decision-making, as frequent interaction with others regulates our behavior. Neuroimaging studies show that social-based and fairness-related decision-making activates an inconsistent set of areas, which sometimes includes the anterior insula, anterior cingulate cortex, and others lateral prefrontal cortices. Social-based decision-making is complex and variability in findings may be driven by socio-cognitive activities related to social norms. To distinguish among social-cognitive activities related to social norms, we identified 36 eligible articles in the functional magnetic resonance imaging (fMRI) literature, which we separate into two categories (a) social norm representation and (b) norm violations...
November 21, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/29160600/current-evidence-of-cannabinoid-based-analgesia-obtained-in-preclinical-and-human-experimental-settings
#14
REVIEW
J Lötsch, I Weyer-Menkhoff, I Tegeder
Cannabinoids have a long record of recreational and medical use and become increasingly approved for pain therapy. This development is based on preclinical and human experimental research summarized in this review. Cannabinoid CB1 receptors are widely expressed throughout the nociceptive system. Their activation by endogenous or exogenous cannabinoids modulates the release of neurotransmitters. This is reflected in antinociceptive effects of cannabinoids in preclinical models of inflammatory, cancer and neuropathic pain, and by nociceptive hypersensitivity of cannabinoid receptor-deficient mice...
November 21, 2017: European Journal of Pain: EJP
https://www.readbyqxmd.com/read/29158879/changes-in-effective-connectivity-network-patterns-in-drug-abusers-treated-with-different-methods
#15
Arash Zare Sadeghi, Amir Homayoun Jafari, Mohammad Ali Oghabian, Hamid Reza Salighehrad, Seyed Amir Hossein Batouli, Samira Raminfard, Hamed Ekhtiari
Introduction: Various treatment methods for drug abusers will result in different success rates. This is partly due to different neural assumptions and partly due to various rate of relapse in abusers because of different circumstances. Investigating the brain activation networks of treated subjects can reveal the hidden mechanisms of the therapeutic methods. Methods: We studied three groups of subjects: heroin abusers treated with abstinent based therapy (ABT) method, heroin abusers treated with Methadone Maintenance Therapy (MMT) method, and a control group...
July 2017: Basic and Clinical Neuroscience
https://www.readbyqxmd.com/read/29158202/dynamic-effective-connectivity-in-resting-state-fmri
#16
Hae-Jeong Park, Karl J Friston, Chongwon Pae, Bumhee Park, Adeel Razi
Context-sensitive and activity-dependent fluctuations in connectivity underlie functional integration in the brain and have been studied widely in terms of synaptic plasticity, learning and condition-specific (e.g., attentional) modulations of synaptic efficacy. This dynamic aspect of brain connectivity has recently attracted a lot of attention in the resting state fMRI community. To explain dynamic functional connectivity in terms of directed effective connectivity among brain regions, we introduce a novel method to identify dynamic effective connectivity using spectral dynamic causal modelling (spDCM)...
November 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/29155843/the-relation-between-statistical-power-and-inference-in-fmri
#17
Henk R Cremers, Tor D Wager, Tal Yarkoni
Statistically underpowered studies can result in experimental failure even when all other experimental considerations have been addressed impeccably. In fMRI the combination of a large number of dependent variables, a relatively small number of observations (subjects), and a need to correct for multiple comparisons can decrease statistical power dramatically. This problem has been clearly addressed yet remains controversial-especially in regards to the expected effect sizes in fMRI, and especially for between-subjects effects such as group comparisons and brain-behavior correlations...
2017: PloS One
https://www.readbyqxmd.com/read/29146377/cortical-processing-of-pitch-model-based-encoding-and-decoding-of-auditory-fmri-responses-to-real-life-sounds
#18
REVIEW
Vittoria De Angelis, Federico De Martino, Michelle Moerel, Roberta Santoro, Lars Hausfeld, Elia Formisano
Pitch is a perceptual attribute related to the fundamental frequency (or periodicity) of a sound. So far, the cortical processing of pitch has been investigated mostly using synthetic sounds. However, the complex harmonic structure of natural sounds may require different mechanisms for the extraction and analysis of pitch. This study investigated the neural representation of pitch in human auditory cortex using model-based encoding and decoding analyses of high field (7 T) functional magnetic resonance imaging (fMRI) data collected while participants listened to a wide range of real-life sounds...
November 13, 2017: NeuroImage
https://www.readbyqxmd.com/read/29138088/comparing-multilayer-brain-networks-between-groups-introducing-graph-metrics-and-recommendations
#19
Kanad Mandke, Jil Meier, Matthew J Brookes, Reuben D O'Dea, Piet Van Mieghem, Cornelis J Stam, Arjan Hillebrand, Prejaas Tewarie
There is an increasing awareness of the advantages of multi-modal neuroimaging. Networks obtained from different modalities are usually treated in isolation, which is however contradictory to accumulating evidence that these networks show non-trivial interdependencies. Even networks obtained from a single modality, such as frequency-band specific functional networks measured from magnetoencephalography (MEG) are often treated independently. Here, we discuss how a multilayer network framework allows for integration of multiple networks into a single network description and how graph metrics can be applied to quantify multilayer network organisation for group comparison...
November 11, 2017: NeuroImage
https://www.readbyqxmd.com/read/29134717/superior-colliculus-resting-state-networks-in-post-traumatic-stress-disorder-and-its-dissociative-subtype
#20
Isadora Olivé, Maria Densmore, Sherain Harricharan, Jean Théberge, Margaret C McKinnon, Ruth Lanius
OBJECTIVES: The innate alarm system (IAS) models the neurocircuitry involved in threat processing in posttraumatic stress disorder (PTSD). Here, we investigate a primary subcortical structure of the IAS model, the superior colliculus (SC), where the SC is thought to contribute to the mechanisms underlying threat-detection in PTSD. Critically, the functional connectivity between the SC and other nodes of the IAS remains unexplored. EXPERIMENTAL DESIGN: We conducted a resting-state fMRI study to investigate the functional architecture of the IAS, focusing on connectivity of the SC in PTSD (n = 67), its dissociative subtype (n = 41), and healthy controls (n = 50) using region-of-interest seed-based analysis...
November 13, 2017: Human Brain Mapping
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