scholarly journals Theta-Band Functional Connectivity and Single-Trial Cognitive Control in Sports-Related Concussion: Demonstration of Proof-of-Concept for a Potential Biomarker of Concussion

2019 ◽  
Vol 25 (3) ◽  
pp. 314-323 ◽  
Author(s):  
Ezra E. Smith ◽  
John J.B. Allen
Keyword(s):  
Head Injury ◽  
Functional Connectivity ◽  
Cognitive Control ◽  
Phase Synchronization ◽  
Control Measures ◽  
Single Trial ◽  
Brain Health ◽  
Theta Band ◽  
College Age ◽  
Potential Biomarker

AbstractObjectives: This report examined theta-band neurodynamics for potential biomarkers of brain health in athletes with concussion. Methods: Participants included college-age contact/collision athletes with (N=24) and without a history of concussion (N=16) in Study 1. Study 2 (N=10) examined changes over time in contact/collision athletes. There were two primary dependent variables: (1) theta-band phase-synchronization (e.g., functional connectivity) between medial and right-lateral electrodes; and (2) the within-subject correlation between synchronization strength on error trials and post-error reaction time (i.e., operationalization of cognitive control). Results: Head injury history was inversely related with medial-lateral connectivity. Head injury was also related to declines in a neurobehavioral measure of cognitive control (i.e., the single-trial relationship between connectivity and post-error slowing). Conclusions: Results align with a theory of connectivity-mediated cognitive control. Mild injuries undetectable by behavioral measures may still be apparent on direct measures of neural functioning. This report demonstrates that connectivity and cognitive control measures may be useful for tracking recovery from concussion. Theoretically relevant neuroscientific findings in healthy adults may have applications in patient populations, especially with regard to monitoring brain health. (JINS 2019, 25, 314–323)

scholarly journals EEG Functional Connectivity and Cognitive Variables in Premanifest and Manifest Huntington’s Disease: EEG Low-Resolution Brain Electromagnetic Tomography (LORETA) Study

2020 ◽  
Vol 11 ◽  
Author(s):  
Marianna Delussi ◽  
Virgilio Nazzaro ◽  
Katia Ricci ◽  
Marina de Tommaso
Keyword(s):  
Functional Connectivity ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Phase Synchronization ◽  
Word Reading ◽  
Current Source ◽  
Low Resolution ◽  
Potential Biomarker ◽  
Eeg Functional Connectivity ◽  
Lagged Phase Synchronization

BackgroundScientific literature does not offer sufficient data on electroencephalography (EEG) functional connectivity and its correlations with clinical and cognitive features in premanifest and manifest HD.AimThis study tries to identify abnormal EEG patterns of functional connectivity, in conditions of “brain resting state” and correlations with motor decline and cognitive variable in Huntington’s disease (HD), in premanifest and manifest phase, looking for a reliable marker measuring disease progression.MethodThis was an observational cross-sectional study; 105 subjects with age ≥18 years submitted to HD genetic test. Each subject underwent a neurological, psychiatric, and cognitive assessment, EEG recording and genetic investigation for detecting the expansion of the CAG trait. EEG connectivity analysis was performed by means of exact Low Resolution Electric Tomography (eLORETA) in 18 premanifest HD (pHD), 49 manifest HD (mHD), and 38 control (C) subjects.ResultsHD patients showed a Power Spectral Density reduced in the alpha range and increased in delta band compared to controls; no difference was detectable between pHD and mHD; the Global Connectivity in pHD revealed no significant differences if compared to mHD. The Current Source Density was similar among groups. No statistically significant results when comparing pHD with C group, even in comparison of mHD with Controls, and pHD with mHD. mHD compared to Controls showed a significant increase in delta, alpha1, alpha2, beta2, and beta3. Lagged Phase Synchronization in delta, alpha1, alpha2, beta2, and beta3 bands was increased in HD compared to controls (t = −3.921, p < 0.05). A significant correlation was found in Regression Analysis: statistically significant results in pHD for the “Symbol Digit Modality Test and lagged phase synchronization” in the Beta1 (r = −0.806, p < 0.05) in the prefrontal regions. The same correlation was found in mHD for the Stroop Word Reading Test (SWRT) in the Alpha2 band (r = −0.759, p < 0.05).ConclusionIncreased phase synchronization in main bands characterized EEG in HD patients, as compared to controls. pHD were not dissimilar from mHD as regard to this EEG pattern. Increased phase synchronization correlated to cognitive decline in HD patients, with a similar trend in pHD, suggesting that it would be a potential biomarker of early phenotypical expression.

Functional Connectivity Alterations Based on the Weighted Phase Lag Index: An Exploratory Electroencephalography Study on Alzheimer’s Disease

2021 ◽  
Vol 18 ◽  
Author(s):  
Yi Yan ◽  
Aonan Zhao ◽  
Yinghui Qiu ◽  
Yanfei Ding ◽  
Ying Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Functional Connectivity ◽  
Phase Synchronization ◽  
Significant Negative Correlation ◽  
Phase Lag ◽  
Connection Strength ◽  
Theta Band ◽  
Delta Band ◽  
Weighted Phase Lag Index

Objectives: Numerous electroencephalography (EEG) studies focus on the alteration of electrical activity in patients with Alzheimer’s Disease (AD), but there are no consistent results es- pecially regarding functional connectivity. We supposed that the weighted Phase Lag Index (w- PLI), as phase-based measures of functional connectivity, may be used as an auxiliary diagnostic method for AD. Methods: We enrolled 30 patients with AD, 30 patients with Mild Cognitive Impairment (MCI), and 30 Healthy Controls (HC). EEGs were recorded in all participants at baseline during relaxed wakefulness. Following EEG preprocessing, Power Spectral Density (PSD) and wPLI parameters were determined to further analyze whether they were correlated to cognitive scores. Results: In the patients with AD, the increased PSD in theta band was presented compared with MCI and HC groups, which was associated with disturbances of the directional, computational, and delayed memory capacity. Furthermore, the wPLI revealed a distinctly lower connection strength between frontal and distant areas in the delta band and a higher connection strength of the central and temporo-occipital region in the theta band for AD patients. Moreover,we found a significant negative correlation between theta functional connectivity and cognitive scores. Conclusions: Increased theta PSD and decreased delta wPLI may be one of the earliest changes in AD and associated with disease severity. The parameter wPLI is a novel measurement of phase synchronization and has potentials in understanding underlying functional connectivity and aiding in the diagnostics of AD.

scholarly journals The role of salivary vesicles as a potential inflammatory biomarker to detect traumatic brain injury in mixed martial artists

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rani Matuk ◽  
Mandy Pereira ◽  
Janette Baird ◽  
Mark Dooner ◽  
Yan Cheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Head Injury ◽  
Injury Severity ◽  
Expression Profiles ◽  
High Impact ◽  
Impact Mechanism ◽  
Inflammatory Biomarker ◽  
Potential Biomarker

AbstractTraumatic brain injury (TBI) is of significant concern in the realm of high impact contact sports, including mixed martial arts (MMA). Extracellular vesicles (EVs) travel between the brain and oral cavity and may be isolated from salivary samples as a noninvasive biomarker of TBI. Salivary EVs may highlight acute neurocognitive or neuropathological changes, which may be particularly useful as a biomarker in high impact sports. Pre and post-fight samples of saliva were isolated from 8 MMA fighters and 7 from controls. Real-time PCR of salivary EVs was done using the TaqMan Human Inflammatory array. Gene expression profiles were compared pre-fight to post-fight as well as pre-fight to controls. Largest signals were noted for fighters sustaining a loss by technical knockout (higher impact mechanism of injury) or a full match culminating in referee decision (longer length of fight), while smaller signals were noted for fighters winning by joint or choke submission (lower impact mechanism as well as less time). A correlation was observed between absolute gene information signals and fight related markers of head injury severity. Gene expression was also significantly different in MMA fighters pre-fight compared to controls. Our findings suggest that salivary EVs as a potential biomarker in the acute period following head injury to identify injury severity and can help elucidate pathophysiological processes involved in TBI.

Reading in children with drug‐resistant epilepsy was related to functional connectivity in cognitive control regions

2020 ◽  
Vol 109 (10) ◽  
pp. 2105-2111
Author(s):  
Dror Kraus ◽  
Jennifer Vannest ◽  
Ravindra Arya ◽  
John S. Hutton ◽  
James L. Leach ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Cognitive Control ◽  
Drug Resistant ◽  
Drug Resistant Epilepsy ◽  
Control Regions

Selection for Action: The Medial Frontal Cortex Is an Executive Hub for Stimulus and Response Selection

2021 ◽  
pp. 1-28
Author(s):  
Dariusz Asanowicz ◽  
Bartłomiej Panek ◽  
Ilona Kotlewska
Keyword(s):  
Functional Connectivity ◽  
Frontal Cortex ◽  
Phase Synchronization ◽  
Visual Stimulation ◽  
Response Selection ◽  
Flanker Task ◽  
Medial Frontal Cortex ◽  
Conflict Condition ◽  
Underlying Processes ◽  
Selection For Action

Abstract This EEG study investigates the electrophysiological activity underlying processes of stimulus and response selection, and their executive orchestration via long-range functional connectivity under conflict condition, in order to shed more light on how these brain dynamics shape individual behavioral performance. Participants (n = 91) performed a modified flanker task, in which bilateral visual stimulation and a bimanual response pattern were employed to isolate the stimulus and response selection-related lateralized activity. First, we identified conflict-related markers of task-relevant processes; most importantly, the stimulus and response selection were evidenced by contra–ipsilateral differences in visual and motor activity, respectively, and executive control was evidenced by modulations of midfrontal activity. Second, we identified conflict-related functional connectivity between midfrontal and other task-relevant areas. The results showed that interregional phase synchronization in theta band was centered at the midfrontal site, interpreted here as a “hub” of executive communication. Importantly, the theta functional connectivity was more robust under the condition of increased demands for stimulus and response selection, including connectivity between the medial frontal cortex and the lateral frontal and motor areas, as well as cross-frequency theta–alpha coupling between the medial frontal cortex and contralateral visual areas. Third, we showed that individual differences in the measured conflict-related EEG activity, particularly the midfrontal N2, theta power, and global theta connectivity, predict the behavioral efficiency in conflict resolution.

scholarly journals qEEG Analysis in the Diagnosis of Alzheimers Disease; a Comparison of Functional Connectivity and Spectral Analysis

2022 ◽  
Author(s):  
Maria Semeli Frangopoulou ◽  
Maryam Alimardani
Keyword(s):  
Spectral Analysis ◽  
Functional Connectivity ◽  
Data Science ◽  
Phase Synchronization ◽  
Connectivity Analysis ◽  
Alzheimers Disease ◽  
Brain Disorder ◽  
Alternative Analysis ◽  
Functional Connectivity Analysis ◽  
Analysis Methods

Alzheimers disease (AD) is a brain disorder that is mainly characterized by a progressive degeneration of neurons in the brain, causing a decline in cognitive abilities and difficulties in engaging in day-to-day activities. This study compares an FFT-based spectral analysis against a functional connectivity analysis based on phase synchronization, for finding known differences between AD patients and Healthy Control (HC) subjects. Both of these quantitative analysis methods were applied on a dataset comprising bipolar EEG montages values from 20 diagnosed AD patients and 20 age-matched HC subjects. Additionally, an attempt was made to localize the identified AD-induced brain activity effects in AD patients. The obtained results showed the advantage of the functional connectivity analysis method compared to a simple spectral analysis. Specifically, while spectral analysis could not find any significant differences between the AD and HC groups, the functional connectivity analysis showed statistically higher synchronization levels in the AD group in the lower frequency bands (delta and theta), suggesting that the AD patients brains are in a phase-locked state. Further comparison of functional connectivity between the homotopic regions confirmed that the traits of AD were localized in the centro-parietal and centro-temporal areas in the theta frequency band (4-8 Hz). The contribution of this study is that it applies a neural metric for Alzheimers detection from a data science perspective rather than from a neuroscience one. The study shows that the combination of bipolar derivations with phase synchronization yields similar results to comparable studies employing alternative analysis methods.

scholarly journals Algebra dissociates from arithmetic in the brain semantic network

2022 ◽  
Vol 18 (1) ◽  
Author(s):  
Dazhi Cheng ◽  
Mengyi Li ◽  
Jiaxin Cui ◽  
Li Wang ◽  
Naiyi Wang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Supplementary Motor Area ◽  
Semantic Network ◽  
Brain Activation ◽  
Motor Area ◽  
Angular Gyrus ◽  
Single Trial ◽  
Positive Functional ◽  
Brain Behavior ◽  
The Brain

Abstract Background Mathematical expressions mainly include arithmetic (such as 8 − (1 + 3)) and algebra (such as a − (b + c)). Previous studies have shown that both algebraic processing and arithmetic involved the bilateral parietal brain regions. Although previous studies have revealed that algebra was dissociated from arithmetic, the neural bases of the dissociation between algebraic processing and arithmetic is still unclear. The present study uses functional magnetic resonance imaging (fMRI) to identify the specific brain networks for algebraic and arithmetic processing. Methods Using fMRI, this study scanned 30 undergraduates and directly compared the brain activation during algebra and arithmetic. Brain activations, single-trial (item-wise) interindividual correlation and mean-trial interindividual correlation related to algebra processing were compared with those related to arithmetic. The functional connectivity was analyzed by a seed-based region of interest (ROI)-to-ROI analysis. Results Brain activation analyses showed that algebra elicited greater activation in the angular gyrus and arithmetic elicited greater activation in the bilateral supplementary motor area, left insula, and left inferior parietal lobule. Interindividual single-trial brain-behavior correlation revealed significant brain-behavior correlations in the semantic network, including the middle temporal gyri, inferior frontal gyri, dorsomedial prefrontal cortices, and left angular gyrus, for algebra. For arithmetic, the significant brain-behavior correlations were located in the phonological network, including the precentral gyrus and supplementary motor area, and in the visuospatial network, including the bilateral superior parietal lobules. For algebra, significant positive functional connectivity was observed between the visuospatial network and semantic network, whereas for arithmetic, significant positive functional connectivity was observed only between the visuospatial network and phonological network. Conclusion These findings suggest that algebra relies on the semantic network and conversely, arithmetic relies on the phonological and visuospatial networks.

scholarly journals Influences of affective context on amygdala functional connectivity during cognitive control from adolescence through adulthood

2020 ◽  
Vol 45 ◽  
pp. 100836
Author(s):  
Orma Ravindranath ◽  
Sarah J. Ordaz ◽  
Aarthi Padmanabhan ◽  
William Foran ◽  
Maria Jalbrzikowski ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Cognitive Control
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