Background: Over the last few years much research has been devoted to investigating the synchronization between cortical motor and muscular activity as measured by EEG/MEG-EMG coherence. The main focus so far has been on corticomuscular coherence (CMC) during static force condition, for which coherence in beta-range has been described. In contrast, we showed in a recent study 1 that dynamic force condition is accompanied by gamma-range CMC. The modulation of the CMC by various dynamic force amplitudes, however, remained uninvestigated. The present study addresses this question. We examined eight healthy human subjects. EEG and surface EMG were recorded simultaneously. The visuomotor task consisted in isometric compensation for 3 forces (static, small and large dynamic) generated by a manipulandum. The CMC, the cortical EEG spectral power (SP), the EMG SP and the errors in motor performance (as the difference between target and exerted force) were analyzed.

Results: For the static force condition we found the well-documented, significant beta-range CMC (15-30 Hz) over the contralateral sensorimotor cortex. Gamma-band CMC (30-45 Hz) occurred in both small and large dynamic force conditions without any significant difference between both conditions. Although in some subjects beta-range CMC was observed during both dynamic force conditions no significant difference between conditions could be detected. With respect to the motor performance, the lowest errors were obtained in the static force condition and the highest ones in the dynamic condition with large amplitude. However, when we normalized the magnitude of the errors to the amplitude of the applied force (relative errors) no significant difference between both dynamic conditions was observed.

Conclusion: These findings confirm that during dynamic force output the corticomuscular network oscillates at gamma frequencies. Moreover, we show that amplitude modulation of dynamic force has no effect on the gamma CMC in the low force range investigated. We suggest that gamma CMC is rather associated with the internal state of the sensorimotor system as supported by the unchanged relative error between both dynamic conditions.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2245954PMC
http://dx.doi.org/10.1186/1471-2202-8-101DOI Listing

Publication Analysis

Top Keywords

dynamic force
28
force condition
16
force
13
small large
12
large dynamic
12
static force
12
dynamic
11
cmc
9
force output
8
motor performance
8

Similar Publications

: The impact of shoe stiffness on running biomechanics is well-documented, while the specific effect on the performance of biomechanically distinct groups such as novice runners and experienced runners is still largely unexplored. The study aimed to evaluate the biomechanical effect of different shoe longitudinal bending stiffness on the lower limb during running in novice runners and experienced runners. : Twelve experienced runners and ten novice runners ran at a speed of 4.

View Article and Find Full Text PDF

Highly deformable flapping membrane wings suppress the leading edge vortex in hover to perform better.

Proc Natl Acad Sci U S A

February 2025

École polytechnique fédérale de Lausanne, School of Engineering, Institute of Mechanical Engineering, Unsteady Flow Diagnostics Laboratory, Lausanne 1015, Switzerland.

Airborne insects generate a leading edge vortex when they flap their wings. This coherent vortex is a low-pressure region that enhances the lift of flapping wings compared to fixed wings. Insect wings are thin membranes strengthened by a system of veins that does not allow large wing deformations.

View Article and Find Full Text PDF

Enzyme-enzyme interactions are fundamental to the function of cells. Their atomistic mechanisms remain elusive mainly due to limitations of in-cell measurements. We address this challenge by atomistically modeling, for a total of ≈80 μs, a slice of the human cell cytoplasm that includes three successive enzymes along the glycolytic pathway: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK), and phosphoglycerate mutase (PGM).

View Article and Find Full Text PDF

In 2025 the changes in national leadership cast a surprising light and ineffable shadows on America's race, gender and class dynamics. Unexpectedly, women and people of color did not vote as a monolithic force in favor of one side or another of culture wars. In the health promotion discipline alarms are being sounded that America's new political leadership will use their newfound popularity among a wider constituency to question the integrity of public health and challenge the value of science writ large.

View Article and Find Full Text PDF

Symmetry Breaking: Case Studies with Organic Cage-Racemates.

Acc Chem Res

January 2025

School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.

ConspectusSymmetry is a pervasive phenomenon spanning diverse fields, from art and architecture to mathematics and science. In the scientific realms, symmetry reveals fundamental laws, while symmetry breaking─the collapse of certain symmetry─is the underlying cause of phenomena. Research on symmetry and symmetry breaking consistently provides valuable insights across disciplines, from parity violation in physics to the origin of homochirality in biology.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!