scholarly journals Induced Gamma-Band Activity during Actual and Imaginary Movements: EEG Analysis

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1545
Author(s):  
Carlos Amo Usanos ◽  
Luciano Boquete ◽  
Luis de Santiago ◽  
Rafael Barea Navarro ◽  
Carlo Cavaliere

The purpose of this paper is to record and analyze induced gamma-band activity (GBA) (30–60 Hz) in cerebral motor areas during imaginary movement and to compare it quantitatively with activity recorded in the same areas during actual movement using a simplified electroencephalogram (EEG). Brain activity (basal activity, imaginary motor task and actual motor task) is obtained from 12 healthy volunteer subjects using an EEG (Cz channel). GBA is analyzed using the mean power spectral density (PSD) value. Event-related synchronization (ERS) is calculated from the PSD values of the basal GBA (GBAb), the GBA of the imaginary movement (GBAim) and the GBA of the actual movement (GBAac). The mean GBAim and GBAac values for the right and left hands are significantly higher than the GBAb value (p = 0.007). No significant difference is detected between mean GBA values during the imaginary and actual movement (p = 0.242). The mean ERS values for the imaginary movement (ERSimM (%) = 23.52) and for the actual movement (ERSacM = 27.47) do not present any significant difference (p = 0.117). We demonstrated that ERS could provide a useful way of indirectly checking the function of neuronal motor circuits activated by voluntary movement, both imaginary and actual. These results, as a proof of concept, could be applied to physiology studies, brain–computer interfaces, and diagnosis of cognitive or motor pathologies.

2018 ◽  
Vol 9 (1) ◽  
pp. 63-79
Author(s):  
Meghan McGowan ◽  
Camille Hémond-Hill ◽  
Justine Nakazawa

 The bereitschaftspotential (BP)—also known as the readiness potential—is a measure of brain activity that precedes voluntary movement by approximately one second in the supplementary motor area and the contralateral primary motor cortex. Motor task reaction time for bimanual task performance is affected by both the individual and the environment; however, it is unclear whether motor task reaction time (as measured via the BP) is significantly affected by congruency. A congruent motor task is an ipsilateral stimulus (e.g., a stimulus on the right is responded to by the right hand), and an incongruent task is a contralateral stimulus (e.g., a stimulus on the right is responded to by the left hand). Congruency is re-emerging as an important topic in motor learning as it may require different levels of cortical processing. The purpose of this study was to examine the effect of congruency on the BP. Participants were asked to complete the computer task, Keyboard Hero, where they pressed keys with both their left and right hands in response to discrete congruent and incongruent stimuli. A MUSE™  apparatus recorded brain activity 1000 ms prior to, and 1000 ms after each stimulus. Results from every participant for the incongruent and congruent trials were averaged and compared using a grand average waveform. Means of accuracy (how often participants pressed the key correctly) and BP for each condition were averaged and compared using a 95% Confidence Interval (CI). Across congruent and incongruent conditions, a non-significant difference (p > 0.05 ) was found in BP (p > 0.59 ), accuracy (p > 0.64 ), and BP within −200  ms to 200 ms (p > 0.31 ). BP and mean accuracy scores were not significantly different between congruent and incongruent conditions, which may be due to only minute differences in brain activity or due to the study’s design. Further research should analyze individual variations of the present study, such as stimulus location, differences in the responding limb, correctness of responses, and the sensory modality being tested


2016 ◽  
Vol 3 (3) ◽  
pp. 150593 ◽  
Author(s):  
Gavin Perry

It has been suggested that gamma (30–100 Hz) oscillations mediate awareness of visual stimuli, but tests of this hypothesis have produced differing results. We used phase scrambling to vary the perceptibility of face stimuli in order to determine whether gamma is indeed linked to perceptual awareness. Magnetoencephalography was used to measure the gamma response in 25 participants while viewing three conditions in which faces were presented either above, below or at the threshold for detection. In each of 400 trials (100 each for the sub- and suprathreshold conditions, 200 for the threshold condition), participants indicated whether they perceived a face in the stimulus. Gamma-band activity during the task was localized to bilateral ventral occipito-temporal cortex. For the threshold condition, we failed to find a significant difference in gamma amplitude between trials in which a face was perceived relative to those in which no face was perceived. However, we did find that gamma amplitude was significantly increased for threshold relative to subthreshold stimuli and for suprathreshold relative to threshold stimuli. This leads us to conclude that the gamma response to faces is primarily modulated by the presence of sensory evidence of a face rather by perceptual awareness.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 526.1-526
Author(s):  
L. Nacef ◽  
H. Riahi ◽  
Y. Mabrouk ◽  
H. Ferjani ◽  
K. Maatallah ◽  
...  

Background:Hypertension, diabetes, and dyslipidemia are traditional risk factors of cardiac events. Carotid ultrasonography is an available way to detect subclinical atherosclerosis.Objectives:This study aimed to compare the intima-media thickness in RA patients based on their personal cardiovascular (CV) history of hypertension (hypertension), diabetes, and dyslipidemia.Methods:The present study is a prospective study conducted on Tunisian RA patients in the rheumatology department of Mohamed Kassab University Hospital (March and December 2020). The characteristics of the patients and those of the disease were collected.The high-resolution B-mode carotid US measured the IMT, according to American Society of Echocardiography guidelines. The carotid bulb below its bifurcation and the internal and external carotid arteries were evaluated bilaterally with grayscale, spectral, and color Doppler ultrasonography using proprietary software for carotid artery measurements. IMT was measured using the two inner layers of the common carotid artery, and an increased IMT was defined as ≥0.9 mm. A Framingham score was calculated to predict the cardiovascular risk at 10-year.Results:Forty-seven patients were collected, 78.7% of whom were women. The mean age was 52.5 ±11.06 [32-76]. The rheumatoid factor (RF) was positive in 57.8% of cases, and anti-citrullinated peptide antibodies (ACPA) were positive in 62.2% of cases. RA was erosive in 81.6% of cases. Hypertension (hypertension) was present in 14.9% of patients, diabetes in 12.8% of patients, and dyslipidemia in 12.8% of patients. Nine patients were active smokers. The mean IMT in the left common carotid (LCC) was 0.069 ±0.015, in the left internal carotid (LIC) was 0.069 ±0.015, in the left external carotid (LEC) was 0.060 ±0.023. The mean IMT was 0.068 ±0.01 in the right common carotid (RCC), 0.062 ±0.02 in the right internal carotid (RIC), and 0.060 ±0.016 in the right external carotid (REC). The IMT was significantly higher in the left common carotid (LCC) in patients with hypertension (p=0.025). There was no significant difference in the other ultrasound sites (LIC, LEC, RCC, RIC, and REC) according to the presence or absence of hypertension. The IMT was also significantly increased in patients with diabetes at LCC (p=0.017) and RIC (p=0.025). There was no significant difference in the IMT at different ultrasound sites between patients with and without dyslipidemia.Conclusion:Hypertension was significantly associated with the increase in IMT at the LCC level in RA patients. Diabetes had an impact on IMT in LCC and RIC. However, dyslipidemia did not affect the IMT at the different ultrasound sites.References:[1]S. Gunter and al. Arterial wave reflection and subclinical atherosclerosis in rheumatoid arthritis. Clinical and Experimental Rheumatology 2018; 36: Clinical E.xperimental.[2]Aslan and al. Assessment of local carotid stiffness in seronegative and seropositive rheumatoid arthritis. SCANDINAVIAN CARDIOVASCULAR JOURNAL, 2017.[3]Martin I. Wah-Suarez and al, Carotid ultrasound findings in rheumatoid arthritis and control subjects: A case-control study. Int J Rheum Dis. 2018;1–7.[4]Gobbic C and al. Marcadores subclínicos de aterosclerosis y factores de riesgo cardiovascular en artritis temprana. Subclinical markers of atherosclerosis and cardiovascular risk factors in early arthritis marcadores subclínicos de aterosclerose e fatores de risco cardiovascular na artrite precoce.Disclosure of Interests:None declared


2001 ◽  
Vol 112 (7) ◽  
pp. 1219-1228 ◽  
Author(s):  
I.G Gurtubay ◽  
M Alegre ◽  
A Labarga ◽  
A Malanda ◽  
J Iriarte ◽  
...  

PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e44215 ◽  
Author(s):  
Nicholas Maling ◽  
Rowshanak Hashemiyoon ◽  
Kelly D. Foote ◽  
Michael S. Okun ◽  
Justin C. Sanchez

2006 ◽  
Vol 43 (6) ◽  
pp. 533-540 ◽  
Author(s):  
Atsushi Matsumoto ◽  
Yoko Ichikawa ◽  
Noriaki Kanayama ◽  
Hideki Ohira ◽  
Tetsuya Iidaka

2008 ◽  
Vol 115 (9) ◽  
pp. 1301-1311 ◽  
Author(s):  
J. A. van Deursen ◽  
E. F. P. M. Vuurman ◽  
F. R. J. Verhey ◽  
V. H. J. M. van Kranen-Mastenbroek ◽  
W. J. Riedel

Cephalalgia ◽  
2007 ◽  
Vol 27 (12) ◽  
pp. 1360-1367 ◽  
Author(s):  
G Coppola ◽  
A Ambrosini ◽  
L Di Clemente ◽  
D Magis ◽  
A Fumal ◽  
...  

Between attacks, migraineurs lack habituation in standard visual evoked potentials (VEPs). Visual stimuli also evoke high-frequency oscillations in the gamma band range (GBOs, 20–35 Hz) assumed to be generated both at subcortical (early GBOs) and cortical levels (late GBOs). The consecutive peaks of GBOs were analysed regarding amplitude and habituation in six successive blocks of 100 averaged pattern reversal (PR)-VEPs in healthy volunteers and interictally in migraine with (MA) or without aura patients. Amplitude of the two early GBO components in the first PR-VEP block was significantly increased in MA patients. There was a significant habituation deficit of the late GBO peaks in migraineurs. The increased amplitude of early GBOs could be related to the increased interictal visual discomfort reported by patients. We hypothesize that the hypo-functioning serotonergic pathways may cause, in line with the thalamocortical dysrhythmia theory, a functional disconnection of the thalamus leading to decreased intracortical lateral inhibition, which can induce dishabituation.


2015 ◽  
Vol 3 (6) ◽  
pp. e12431 ◽  
Author(s):  
Brennon Luster ◽  
Stasia D'Onofrio ◽  
Francisco Urbano ◽  
Edgar Garcia-Rill

Sign in / Sign up

Export Citation Format

Share Document