Beta-Range EEG-EMG Coherence With Isometric Compensation for Increasing Modulated Low-Level Forces

2009 ◽  
Vol 102 (2) ◽  
pp. 1115-1120 ◽  
Author(s):  
Vihren Chakarov ◽  
José Raúl Naranjo ◽  
Jürgen Schulte-Mönting ◽  
Wolfgang Omlor ◽  
Frank Huethe ◽  
...  
Keyword(s):  
Spectral Power ◽  
Broad Band ◽  
Voluntary Contraction ◽  
Separate Analysis ◽  
Force Level ◽  
Beta Band ◽  
Low Level ◽  
Visuomotor Task ◽  
Gamma Range ◽  
Significant Difference

Corticomuscular synchronization has been shown to occur in beta (15–30 Hz) and gamma range (30–45 Hz) during isometric compensation of static and dynamic (periodically modulated) low-level forces, respectively. However, it is still unknown to what extent these synchronization processes in beta and gamma range are modified with increasing modulated force. We addressed this question by investigating the corticomuscular coherence (CMC) between the electroencephalogram (EEG) and electromyogram (EMG) from the first dorsal interosseus muscle (FDI) as well as the cortical and muscular spectral power during a visuomotor task where different levels of a dynamic (modulated) force were used. Seven healthy right-handed female subjects compensated dynamic forces at 8, 16, and 24% of the maximal voluntary contraction (MVC) isometrically with their right index finger. Under the three conditions investigated, we found a broad-band CMC comprising both beta and gamma range and peaking at ∼22 Hz within the beta band. This broad-band coherence increased linearly with higher force level. A separate analysis of the gamma range CMC did not show significant modulation of the CMC by the force levels. EEG and EMG spectral power did not show any significant difference among the three force conditions. Our results favor the view that the function of beta range CMC is not specific for low-level static forces only. The sensorimotor system may resort to stronger and also broader beta-range CMC to generate stable corticospinal interaction during increased force level, as well as when compensating for dynamic modulated forces. This finding re-enforces the importance of the beta-range EEG-EMG coherence in sensorimotor integration.

The strength of the corticospinal coherence depends on the predictability of modulated isometric forces

2013 ◽  
Vol 109 (6) ◽  
pp. 1579-1588 ◽  
Author(s):  
Ignacio Mendez-Balbuena ◽  
Jose Raul Naranjo ◽  
Xi Wang ◽  
Agnieska Andrykiewicz ◽  
Frank Huethe ◽  
...  
Keyword(s):  
Sensory Feedback ◽  
Muscle Activation ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Visuomotor Task ◽  
Gamma Range ◽  
Cortical Motor ◽  
Contralateral Hand ◽  
Hand Motor Area ◽  
Isometric Forces

Isometric compensation of predictably frequency-modulated low forces is associated with corticomuscular coherence (CMC) in beta and low gamma range. It remains unclear how the CMC is influenced by unpredictably modulated forces, which create a mismatch between expected and actual sensory feedback. We recorded electroencephalography from the contralateral hand motor area, electromyography (EMG), and the motor performance of 16 subjects during a visuomotor task in which they had to isometrically compensate target forces at 8% of the maximum voluntary contraction with their right index finger. The modulated forces were presented with predictable or unpredictable frequencies. We calculated the CMC, the cortical motor alpha-, beta-, and gamma-range spectral powers (SP), and the task-related desynchronization (TRD), as well as the EMG SP and the performance. We found that in the unpredictable condition the CMC was significantly lower and associated with lower cortical motor SP, stronger TRD, higher EMG SP, and worse performance. The findings suggest that due to the mismatch between predicted and actual sensory feedback leading to higher computational load and less stationary motor state, the unpredictable modulation of the force leads to a decrease in corticospinal synchrony, an increase in cortical and muscle activation, and a worse performance.

scholarly journals Effect of bilateral contraction on the ability and accuracy of rapid force production at submaximal force level

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247099
Author(s):  
Yoichi Ohta
Keyword(s):  
Grip Force ◽  
Force Production ◽  
Standing Position ◽  
Voluntary Contraction ◽  
Force Level ◽  
Noticeable Effect ◽  
Force Ratio ◽  
Significant Difference ◽  
Small Effect Size ◽  
The Difference

The present study aims to clarify the effects of bilateral contraction on the ability and accuracy of rapid force production at the submaximal force level. Eleven right-handed participants performed rapid gripping as fast and precisely as they could in unilateral (UL) and bilateral (BL) contractions in a standing position. Participants were required to impinge a grip force of 30% and 50% of their maximal voluntary contraction (MVC). Ability and accuracy of rapid force production were evaluated using the rate of force development (RFD) and force error, respectively. The data analysis did not observe a significant difference in the RFD between UL and BL contractions in both 30% (420±86 vs. 413±106%MVC/s, p = 0.34) and 50% of MVC (622±84 vs. 619±103%MVC/s, p = 0.77). Although the RFD to peak force ratio (RFD/PF) in BL contraction was lower than in UL in 30% of MVC (12.8±2.8 vs. 13.4±2.7, p = 0.003), it indicated a small effect size (d = 0.22) of the difference between UL and BL in RFD/PF. The absolute force error of BL contraction was higher than of UL contraction in 30% (4.67±2.64 vs. 3.64±1.13%MVC, p = 0.005) and 50% of MVC (5.53±2.94 vs. 3.53±0.71%MVC, p = 0.009). In addition, medium and large effect sizes were observed in absolute force error from 30% (d = 0.51) and 50% of MVC (d = 0.94), respectively. In conclusion, results indicated that the bilateral contraction reduced in the ability and accuracy of rapid force production at the submaximal force level. Nevertheless, the present results suggest that the noticeable effect of bilateral contraction is more prominent on the accuracy than in the ability of rapid force production at the submaximal force level.

Exploring The Effect of Visual Information Degradation on Human Perception and Performance In A Human-Telerobot System

2020 ◽  
Vol 64 (1) ◽  
pp. 1302-1307
Author(s):  
Richard Stone ◽  
Minglu Wang ◽  
Thomas Schnieders ◽  
Esraa Abdelall
Keyword(s):  
Visual Information ◽  
Human Perception ◽  
Low Level ◽  
Hit Rate ◽  
Word Level ◽  
Level Of Automation ◽  
Significant Difference ◽  
Human Operators ◽  
And Performance ◽  
High Level

Human-robotic interaction system are increasingly becoming integrated into industrial, commercial and emergency service agencies. It is critical that human operators understand and trust automation when these systems support and even make important decisions. The following study focused on human-in-loop telerobotic system performing a reconnaissance operation. Twenty-four subjects were divided into groups based on level of automation (Low-Level Automation (LLA), and High-Level Automation (HLA)). Results indicated a significant difference between low and high word level of control in hit rate when permanent error occurred. In the LLA group, the type of error had a significant effect on the hit rate. In general, the high level of automation was better than the low level of automation, especially if it was more reliable, suggesting that subjects in the HLA group could rely on the automatic implementation to perform the task more effectively and more accurately.

scholarly journals Sensory feedback-dependent coding of arm position in local field potentials of the posterior parietal cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul VanGilder ◽  
Ying Shi ◽  
Gregory Apker ◽  
Christopher A. Buneo
Keyword(s):  
Local Field ◽  
Sensory Feedback ◽  
Posterior Parietal Cortex ◽  
Spectral Power ◽  
Field Potential ◽  
Beta Activity ◽  
Beta Band ◽  
Arm Position ◽  
Multisensory Interactions ◽  
Spiking Activity

AbstractAlthough multisensory integration is crucial for sensorimotor function, it is unclear how visual and proprioceptive sensory cues are combined in the brain during motor behaviors. Here we characterized the effects of multisensory interactions on local field potential (LFP) activity obtained from the superior parietal lobule (SPL) as non-human primates performed a reaching task with either unimodal (proprioceptive) or bimodal (visual-proprioceptive) sensory feedback. Based on previous analyses of spiking activity, we hypothesized that evoked LFP responses would be tuned to arm location but would be suppressed on bimodal trials, relative to unimodal trials. We also expected to see a substantial number of recording sites with enhanced beta band spectral power for only one set of feedback conditions (e.g. unimodal or bimodal), as was previously observed for spiking activity. We found that evoked activity and beta band power were tuned to arm location at many individual sites, though this tuning often differed between unimodal and bimodal trials. Across the population, both evoked and beta activity were consistent with feedback-dependent tuning to arm location, while beta band activity also showed evidence of response suppression on bimodal trials. The results suggest that multisensory interactions can alter the tuning and gain of arm position-related LFP activity in the SPL.

scholarly journals An Analysis of the External Validity of EEG Spectral Power in an Uncontrolled Outdoor Environment during Default and Complex Neurocognitive States

2021 ◽  
Vol 11 (3) ◽  
pp. 330
Author(s):  
Dalton J. Edwards ◽  
Logan T. Trujillo
Keyword(s):  
External Validity ◽  
Spectral Power ◽  
Brain Activity ◽  
Outdoor Environment ◽  
Oscillatory Activity ◽  
Brain State ◽  
Beta Band ◽  
Eeg Spectral Power ◽  
Eeg Power ◽  
Human Participants

Traditionally, quantitative electroencephalography (QEEG) studies collect data within controlled laboratory environments that limit the external validity of scientific conclusions. To probe these validity limits, we used a mobile EEG system to record electrophysiological signals from human participants while they were located within a controlled laboratory environment and an uncontrolled outdoor environment exhibiting several moderate background influences. Participants performed two tasks during these recordings, one engaging brain activity related to several complex cognitive functions (number sense, attention, memory, executive function) and the other engaging two default brain states. We computed EEG spectral power over three frequency bands (theta: 4–7 Hz, alpha: 8–13 Hz, low beta: 14–20 Hz) where EEG oscillatory activity is known to correlate with the neurocognitive states engaged by these tasks. Null hypothesis significance testing yielded significant EEG power effects typical of the neurocognitive states engaged by each task, but only a beta-band power difference between the two background recording environments during the default brain state. Bayesian analysis showed that the remaining environment null effects were unlikely to reflect measurement insensitivities. This overall pattern of results supports the external validity of laboratory EEG power findings for complex and default neurocognitive states engaged within moderately uncontrolled environments.

Exploration of the Development of Children's Empathy

2021 ◽  
pp. 103-112
Author(s):  
Shih-Tseng Tina Huang ◽  
Vinh-Long Tran-Chi
Keyword(s):  
Fourth Graders ◽  
Sixth Graders ◽  
Future Research ◽  
Affective Empathy ◽  
Separate Analysis ◽  
Significant Difference ◽  
Fourth Grade Students ◽  
Dependent Variables ◽  
Grade Difference ◽  
Acceptable Reliability

Empathy is an important social skill. It is believed to play an essential role in socioemotional and moral development. The current study aimed to explore empathy development during childhood especially among students in the primary and middle schools located in Southern Vietnam. Bryant's Empathy Index for children and adolescents was administrated on 403 children, including 210 boys and 193 girls. The results showed that there was no significant difference between boys and girls in affective empathy. The results further indicated that there is a significant grade difference on affective empathy with the fourth-grade students being placed higher than those of the second and the sixth grades. A separate analysis was conducted for each of the dependent variables. It was found that the fourth graders were significantly higher than the second and the sixth graders on Understanding Feelings, Feelings of Sadness and Bryant's Empathy Index respectively. The result also showed that the Vietnamese version of Bryant's Empathy Index has acceptable reliability and can be used for future research.

scholarly journals Exercise tolerance during muscle contractions below and above the critical torque in different muscle groups

2018 ◽  
Vol 43 (2) ◽  
pp. 174-179 ◽  
Author(s):  
Leonardo Henrique Perinotto Abdalla ◽  
Benedito Sérgio Denadai ◽  
Natália Menezes Bassan ◽  
Camila Coelho Greco
Keyword(s):  
Exercise Intensity ◽  
Maximal Voluntary Contraction ◽  
Exercise Tolerance ◽  
Voluntary Contraction ◽  
Knee Extensors ◽  
Isometric Contractions ◽  
Plantar Flexors ◽  
Significant Difference ◽  
Muscle Groups

The objective of this study was to test the hypotheses that end-test torque (ET) (expressed as % maximal voluntary contraction; MVC) is higher for plantar flexors (PF) than knee extensors (KE) muscles, whereas impulse above ET (IET) is higher for KE than PF. Thus, we expected that exercise tolerance would be longer for KE than PF only during the exercise performed above ET. After the determination of MVC, 40 men performed two 5-min all-out tests to determine ET and IET. Eleven participants performed a further 4 intermittent isometric tests, to exhaustion, at ET + 5% and ET – 5%, and 1 test for KE at the exercise intensity (%MVC) corresponding to ET + 5% of PF. The IET (7243.2 ± 1942.9 vs. 3357.4 ± 1132.3 N·m·s) and ET (84.4 ± 24.8 vs. 73.9 ± 19.5 N·m) were significantly lower in PF compared with KE. The exercise tolerance was significantly longer for PF (300.7 ± 156.7 s) than KE (156.7 ± 104.3 s) at similar %MVC (∼60%), and significantly shorter for PF (300.7 ± 156.7 s) than KE (697.0 ± 243.7 s) at ET + 5% condition. However, no significant difference was observed for ET – 5% condition (KE = 1030.2 ± 495.4 s vs. PF = 1028.3 ± 514.4 s). Thus, the limit of tolerance during submaximal isometric contractions is influenced by absolute MVC only during exercise performed above ET, which seems to be explained by differences on both ET (expressed as %MVC) and IET values.

scholarly journals Low-level laser therapy for temporomandibular disorders (tmd) treatment: a systematic review of randomized trials

2014 ◽  
Vol 2 (5) ◽  
pp. 376
Author(s):  
Priscila Leite ◽  
Nicole Melo ◽  
Pâmela Silva ◽  
Robinsom Montenegro ◽  
Paulo Bonan ◽  
...  
Keyword(s):  
Systematic Review ◽  
Temporomandibular Joint ◽  
Laser Therapy ◽  
Diagnostic Criteria ◽  
Temporomandibular Disorders ◽  
Low Level Laser Therapy ◽  
Low Level ◽  
Low Level Laser ◽  
Level Laser ◽  
Significant Difference

AIM: Conducting a systematic review of randomized clinical trials focusing on the efficacy of LLLT on pain control in patients with TMD, diagnosed by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). MATERIAL AND METHODS: Search was performed at PubMed/MEDLINE database with the terms: (1) “Laser AND temporomandibular disorders”; (2) “Laser AND temporomandibular disorders AND RDC/TMD”; (3) “Low-level laser therapy AND temporomandibular disorders”; (4) “Low-level laser therapy AND temporomandibular disorders AND RDC/TMD”; (5) “Low-level laser therapy AND temporomandibular joint dysfuntion syndrome”; (6) “Low-level laser therapy AND temporomandibular joint dysfuntion syndrome AND RDC/TMD”; (7) “Laser AND temporomandibular joint dysfuntion syndrome” (8) “Laser AND RDC/TMD”; (9) “Low-level laser therapy AND RDC/TMD”. Inclusion criteria: articles need to be randomized clinical trial performed in humans; evaluate the effect of LLLT in the treatment of TMD diagnosed by the use of RDC/TMD; published in English or Portuguese in the last 10 years. Protocol studies and pilot studies were excluded. RESULTS: Ten studies were included. The type of laser used was Gallium Aluminum Arsenide (GaAlAs) diode, with exception of 1 paper, which used super pulsed Gallium Arsenide laser. Eight studies reported decreased in pain levels, in two articles there was no statistically significant difference between test and placebo groups. CONCLUSION: In most studies, LLLT was effective in pain remission, but there is no standardization in parameters like wavelength, output power and frequency. Studies with more complex experimental designs, standardized diagnostic criteria for TMD and defined protocols for the use of LLLT are needed to determine its efficacy in the treatment of TMD.

scholarly journals Modulation of magnetoencephalography alpha band activity by radiofrequency electromagnetic field depicted in sensor and source space

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jasmina Wallace ◽  
Lydia Yahia-Cherif ◽  
Christophe Gitton ◽  
Laurent Hugueville ◽  
Jean-Didier Lemaréchal ◽  
...  
Keyword(s):  
High Performance ◽  
Spectral Power ◽  
Heart Rate Variability Analysis ◽  
Alpha Band ◽  
Control Parameters ◽  
Double Blind ◽  
Eyes Closed ◽  
Significant Difference ◽  
Cortical Regions ◽  
Band Activity

AbstractSeveral studies reported changes in spontaneous electroencephalogram alpha band activity related to radiofrequency electromagnetic fields, but findings showed both an increase and a decrease of its spectral power or no effect. Here, we studied the alpha band modulation after 900 MHz mobile phone radiofrequency exposure and localized cortical regions involved in these changes, via a magnetoencephalography (MEG) protocol with healthy volunteers in a double-blind, randomized, counterbalanced crossover design. MEG was recorded during eyes open and eyes closed resting-state before and after radiofrequency exposure. Potential confounding factors, known to affect alpha band activity, were assessed as control parameters to limit bias. Entire alpha band, lower and upper alpha sub-bands MEG power spectral densities were estimated in sensor and source space. Biochemistry assays for salivary biomarkers of stress (cortisol, chromogranin-A, alpha amylase), heart rate variability analysis and high-performance liquid chromatography for salivary caffeine concentration were realized. Results in sensor and source space showed a significant modulation of MEG alpha band activity after the radiofrequency exposure, with different involved cortical regions in relation to the eyes condition, probably because of different attention level with open or closed eyes. None of the control parameters reported a statistically significant difference between experimental sessions.

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