scholarly journals Dynamics of the EEG sensorimotor and alpha rhythm amplitude patterns in a training series of controlling the power platform with visual feedback

2019 ◽  
Vol 70 ◽  
pp. 09006
Author(s):  
Sergei Makhin ◽  
Elena Birukova ◽  
Elena Chuyan ◽  
Oleg Kubryak
Keyword(s):  
Visual Feedback ◽  
Alpha Rhythm ◽  
Right Hemisphere ◽  
Healthy Male ◽  
The Third ◽  
Eeg Alpha ◽  
The Right ◽  
Male Subjects ◽  
Fourth Session ◽  
Regular Patterns

The study of the EEG alpha reactivity patterns in the prefrontal, central, parietal and occipital regions involved 25 healthy male subjects who participated in four training sessions of controlling the power platform with visual feedback. A significant prefrontal alpha rhythm synchronization was found which was not essentially modulated in a series of subsequent trainings. A significant desynchronization of the occipital alpha was registered for the second session which gradually increased up to the fourth session. The sensorimotor alpha rhythm didn’t show regular patterns. The use of the dominant (right) hand resulted in a significant desynchronization of the parietal alpha in the right hemisphere in the third and the fourth training sessions.

CHANGES IN ELECTROENCEPHALOGRAM PATTERN IN RIGHT- AND LEFT-HANDERS DURING IMAGINARY MOVEMENTS

2019 ◽  
pp. 85-92
Author(s):  
K.A. Morenova ◽  
O.A. Vedyasova
Keyword(s):  
Hemispheric Asymmetry ◽  
Alpha Rhythm ◽  
Right Hemisphere ◽  
Eeg Rhythms ◽  
Complex Motor ◽  
Depression Level ◽  
Eeg Alpha ◽  
The Right ◽  
Electroencephalogram Eeg ◽  
Eeg Pattern

The objective of the paper is to analyze changes in electroencephalogram (EEG) pattern in right- and left-handers during imaginary movements of leading and non-leading legs. Materials and Methods. The authors examined 40 right-handers and 20 left-handers, whose motor domination profile was determined by standard tests. EEGs were recorded at rest and during imaginary rotational movements of the right and left legs. NVX 36 digital DC EEG neurovisor, “10–20” system, was used for this perpose. The authors also analyzed the amplitude of the EEG rhythms (standard frequency ranges), evaluated changes in hemispheric asymmetry coefficients of frontal and central alpha and beta1 rhythms as EEG correlates of imaginary activity. Results. Imaginary movements caused a decrease in the amplitude of alpha, beta1, theta and delta rhythms on EEG in all trial subjects. The intensity of observed changes in right- and left-handers differed in symmetrical leads. As for frontal and central alpha and beta1 rhythms, which marked changes in the EEG pattern during imaginary movements, right-handers demonstrated that their depression level in symmetric cortical areas depended significantly on the imaginary movements of leading and non-leading legs and dominated in left or right hemispheres, respectively. For left-handers, changes in alpha and beta1 waves during imaginary movements of leading and non-leading legs did not differ significantly and in both cases dominated in the right hemisphere. Conclusion. Thus, the intra- and inter-hemispheric dynamics of the EEG pattern, while forming the concept and program of complex motor leg actions in left-handers, is alternative in comparison to right-handers. Keywords: EEG, alpha rhythm, beta1 rhythm, imaginary leg movements, hemispheric asymmetry, right-handers, left-handers.

scholarly journals Ethanol Reduces Asymmetry of Visual rCBF Responses

1994 ◽  
Vol 14 (6) ◽  
pp. 963-973 ◽  
Author(s):  
Peter E. Wendt ◽  
Jarl Risberg ◽  
Georg Stenberg ◽  
Ingmar Rosén ◽  
David H. Ingvar
Keyword(s):  
Visual Information ◽  
Right Hemisphere ◽  
Healthy Male ◽  
Posterior Cortex ◽  
Left Posterior ◽  
Before And After ◽  
Posterior Parietal ◽  
Cerebral Vasodilatation ◽  
The Right ◽  
Male Subjects

Visual regional CBF (rCBF) responses were measured in 10 healthy male subjects before and after an ethanol dose of 1 g/kg body weight. This dose induces well-established cerebral vasodilatation. However, significant bilateral occipital increases were found in both conditions. Apparently, the coupling between neuronal activity and rCBF is preserved following ethanol. The occipital and posterior parietal flow increases were, however, larger on the right than the left side in the sober state. During inebriation the asymmetry disappeared, possibly representing a more undifferentiated processing of visual information. We propose that ethanol causes a reduced inhibition of the left posterior cortex and a reduction of right-hemisphere information processing.

Hemispheric Asymmetries in a Signal Detection Task

1983 ◽  
Vol 57 (3) ◽  
pp. 923-929 ◽  
Author(s):  
John L. Andreassi ◽  
Charles S. Rebert ◽  
Ferol F. Larsen
Keyword(s):  
Signal Detection ◽  
Right Hemisphere ◽  
Reaction Times ◽  
Vigilance Task ◽  
Verbal Stimulus ◽  
Right Visual Field ◽  
Left And Right ◽  
The Right ◽  
Male Subjects ◽  
Central Fixation

Reaction time and signal detection performance were measured during a 78-min. vigilance task. 12 right-handed male subjects served in two experimental sessions. Subjects focused on a central fixation point and responded to signals presented at unpredictable times in one of three locations: 2.5° to right of central fixation, central, and 2.5° to the left of center. Subjects decided whether to press a response key with either the left or right hand with each presentation. Over-all vigilance performance (signal detections and response time) was similar for left and right visual-field presentations. Evidence from reaction times indicated that responses controlled by the left hemisphere were faster to a verbal stimulus (T) while reactions controlled by the right hemisphere were faster to an apparent non-verbal stimulus, an inverted T.

Cerebral blood flow velocity in humans exposed to 24 h of head-down tilt

1993 ◽  
Vol 74 (6) ◽  
pp. 3046-3051 ◽  
Author(s):  
Y. Kawai ◽  
G. Murthy ◽  
D. E. Watenpaugh ◽  
G. A. Breit ◽  
C. W. Deroshia ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Linear Regression ◽  
Cerebral Blood Flow Velocity ◽  
Bed Rest ◽  
Healthy Male ◽  
Increased Risk ◽  
The Right ◽  
Male Subjects ◽  
Peak Value

This study investigates cerebral blood flow (CBF) velocity in humans before, during, and after 24 h of 6 degree head-down tilt (HDT), which is a currently accepted experimental model to simulate microgravity. CBF velocity was measured by use of the transcranial Doppler technique in the right middle cerebral artery of eight healthy male subjects. Mean CBF velocity increased from the pre-HDT upright seated baseline value of 55.5 +/- 3.7 (SE) cm/s to 61.5 +/- 3.3 cm/s at 0.5 h of HDT (P < 0.05), reached a peak value of 63.2 +/- 4.1 cm/s at 3 h of HDT, and remained significantly above the pre-HDT baseline for > or = 6 h of HDT. During upright seated recovery (1–5 h post-HDT), mean CBF velocity decreased to 87% of the pre-HDT baseline value (P < 0.05). Mean CBF velocity correlated well with calculated intracranial arterial pressure (IAP) (r = 0.54, P < 0.001). As analyzed by linear regression, mean CBF velocity = 29.6 + 0.32IAP. These results suggest that HDT increases CBF velocity by increasing IAP during several hours after the onset of microgravity. Importantly, the decrease in CBF velocity after HDT may be responsible, in part, for the increased risk of syncope observed in subjects after prolonged bed rest and also in astronauts returning to Earth.

Spatial Frequency-Dependent Asymmetry of Visual Evoked Potential Amplitudes

1996 ◽  
Vol 82 (3) ◽  
pp. 1011-1018
Author(s):  
Karl F. van Orden ◽  
John F. House
Keyword(s):  
Spatial Frequency ◽  
Left Hemisphere ◽  
Evoked Potential ◽  
Right Hemisphere ◽  
Field Configuration ◽  
Sinusoidal Grating ◽  
Pattern Reversal ◽  
Hemispheric Differences ◽  
The Right ◽  
Male Subjects

The extent to which pattern reversal evoked potential amplitudes are distributed symmetrically over the scalp was investigated as a function of stimulus spatial frequency. Nine right-handed male subjects viewed sinusoidal grating stimuli of 4.0 and 0.5 c/deg phase reversed every 900 msec. A visual half-field configuration enabled selective stimulation of the right- or left-hemisphere visual cortex. Evoked responses were recorded from the 2 cm above the inion (Oz) and at 7 and 13 cm lateral to Oz. Analyses of normalized evoked response amplitudes showed a significant asymmetry for the 4.0 c/deg stimulus; right-hemisphere amplitudes declined as a function of distance from the midline, while left-hemisphere amplitudes were greatest at the 7 cm recording site. No hemispheric differences were observed for the 0.5 c/deg stimulus; amplitudes for both hemispheres declined as a function of distance from the midline. The data are discussed in terms of hemispheric differences in morphology and functional asymmetries at early levels of sensory processing.

scholarly journals Peculiarities of electroencephalogram of left-handed individuals in imagination and realiza-tion of feet movements

2018 ◽  
Vol 26 (3) ◽  
pp. 360-368
Author(s):  
Olga A. Vedyasova ◽  
Kseniya A. Morenova
Keyword(s):  
Alpha Rhythm ◽  
Right Hemisphere ◽  
Type I ◽  
Mu Rhythm ◽  
Type Iii ◽  
Left Handed ◽  
Hemisphere Dominance ◽  
Neurophysiological Mechanisms ◽  
The Right ◽  
Motor Acts

Background. Relevance of the study arises from a lack of knowledge about peculiarities of programming and realization of movements in individuals with different profiles of motor dominance. This knowledge is important for understanding the neurophysiological mechanisms of motor functions and for creating neurocomputer interfaces. Aim. The analysis of electroencephalogram (EEG) patterns in lefties during imaginary and real motor acts by right and left legs. Materials and Methods. The left-handed students were examined. They were divided into two groups on the basis of coefficients of motor asymmetry – with low (n=14) and high (n=7) degree of right-hemisphere dominance (LDRD and HDRD). EEG was recorded on neurovisor «NVX 36 digital DC EEG» in standard leads at rest and in successive imagination and fulfilment of movements by the right and left legs. Types of EEG were determined and the amplitude of the sensorimotor alpha-rhythm (mu-rhythm) was evaluated on the basis of analysis of spectral patterns of EEG. Results. It was shown that the majority of left-handed individuals with LDRD had type I EEG, and the minority had type III, whereas all left-handed individuals with HDRD had type I EEG. In imagination and realization of leg movements in the first group the quantity of individuals with EEG of type III increased, while in the second group the type of EEG did not change. Motor tasks were associated with depression of alpha-rhythm in central and frontal areas, but with different extent of evidence in lefties with LDRD and HDRD. More pronounced desynchronization of the central mu-rhythm was observed in left-handed individuals with HDRD, while the amplitude of the frontal alpha-rhythm, on the contrary, was more decreased in left-handed individuals with LDRD. Conclusions. The obtained data show dependence of EEG pattern in left-handed people during imagination and realization of motor acts by the leading and non-leading leg on the degree of the right hemisphere dominance that may find clinical application.

Clustering and switching in divergent thinking: Neurophysiological correlates underlying flexibility during idea generation

2021 ◽  
Author(s):  
Serena Mastria ◽  
Sergio Agnoli ◽  
Marco Zanon ◽  
Selcuk Acar ◽  
Mark Runco ◽  
...  
Keyword(s):  
Divergent Thinking ◽  
Right Hemisphere ◽  
Idea Generation ◽  
Cortical Activation ◽  
Cognitive Resources ◽  
Alpha Band ◽  
Everyday Objects ◽  
Posterior Parietal ◽  
Eeg Alpha ◽  
The Right

EEG alpha synchronization, especially in posterior parietal cortical regions of the right hemisphere, is indicative of high internal processing demands that are typically involved in divergent thinking (DT). During the course of DT, as ideation proceeds, ideas tend to become more creative, being more likely to be drawn from new conceptual categories through the use of the cognitive mechanism of flexibility. The present study investigated whether EEG alpha synchronization can be modulated by flexibility in DT by comparing cortical activation patterns during the switch of category (switching) and the stay in the same category (clustering). Twenty participants were required to generate alternative uses of everyday objects during EEG recording. Differential results were specifically found in the lower alpha band (8-10 Hz): whereas clustering showed synchronization typically lateralized in the right posterior parietal areas, switching induced posterior parietal synchronization over both right and left hemispheres. These findings indicate that the two distinct cognitive mechanisms subsuming flexibility (switching and clustering) are associated with a different hemispheric modulation of lower alpha activity, as switching, in comparison to clustering, is related to higher power in the lower alpha band over the left hemisphere. Switching in comparison to clustering may thus require a larger investment of cognitive resources due to the exploratory process of moving from one semantic conceptual category to another in the course of creative ideation.

Language and Reading in the Right Hemisphere: Highways or Byways of the Brain?

1990 ◽  
Vol 2 (3) ◽  
pp. 159-179 ◽  
Author(s):  
Kathleen Baynes
Keyword(s):  
Individual Variation ◽  
Right Hemisphere ◽  
Reading Processes ◽  
The Third ◽  
Normal Reading ◽  
Reading Errors ◽  
Limited Support ◽  
The Right ◽  
Disconfirming Evidence ◽  
The Brain

The literature pertaining to the representation of language in the right hemisphere of hemispherectomy and callosotomy patients is reviewed to ascertain whether it provides an empirical basis for the assertions that (1) the right hemisphere participates in the recovery of language in aphasia, (2) the right hemisphere mediates the reading errors of deep dyslexic and pure alexic patients, and (3) the right hemisphere plays a fixed role in normal reading processes. At present, there appears to be some support for the first assertion, limited support for the second (if individual variation in representation can be accepted), and disconfirming evidence for the third in the data from these populations.

scholarly journals SPATIAL PICTURE OF DISTRIBUTION OF ELECTROENCEPHALOGRAM RHYTHMS IN THE RIGHT-HANDED STUDENTS DURING AN EXAM

2017 ◽  
Vol 20 (3) ◽  
pp. 202-212
Author(s):  
D.A. Trushina ◽  
O.A. Vedyasova ◽  
M.A. Paramonova
Keyword(s):  
Hemispheric Asymmetry ◽  
Alpha Rhythm ◽  
Right Hemisphere ◽  
Wave Activity ◽  
Eeg Rhythms ◽  
Beta Rhythm ◽  
Delta Waves ◽  
Theta Waves ◽  
The Right ◽  
Electroencephalogram Eeg

Registration of electroencephalogram (EEG) in the right-handed students during an exam revealed weakening of alpha rhythm in all areas of right and left cerebral hemispheres as well as increased beta rhythm in parietal and end-lobes of the right hemisphere. Simultaneously regular delta waves in the frontal leads ofboth hemispheres and theta waves in right frontal, occipitalis and temporal leads were marked. Offset of EEG slow wave activity in the right hemisphere in partial right-handers was marked in more noticeable way than in that of the true right-handers. The obtained data suggest that the distribution of EEG rhythms in condition of mental and emotional stress in right-handers depends on the type and severity of functional hemispheric asymmetry.

Sign in / Sign up

Export Citation Format

Share Document