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Objectives: The map topography analysis gives an idea of temporal dynamics of electric fields, which is reference independent, making the results unambiguous. These topographic maps remain stable for 80 to 100 milliseconds, abruptly shifting to a new topographic map configuration and remains stable in that state are called the ‘functional microstates’ as described by Lehmann et al (1987). There has been no study done in the resting state eye closed and eye open conditions showing the microstate maps in healthy Indian subjects in resting eyes open and resting eyes closed condition using 128 channel EEG. So our study aim was to assess the microstates in resting eyes closed and eyes open condition. And to compare the microstate parameters such as mean duration, global explained variance (GEV) and time coverage between eyes closed and eyes open condition. Materials and Methods: A cross-sectional and observational study on 20 indian subjects (Mean age- 26.65 and (SD) - 2.78 years) was done on resting eyes closed and eyes open conditions. After EEG acquisition using 128 channel EEG machine, EEG was preprocessed and microstate analysis using CARTOOL software was performed on the EEG data. Results: After microstate analysis four maps topography were obtained. There was statistically non-significant difference observed in microstate maps between resting eyes closed and resting eyes open condition for the all parameters i.e. mean duration, time coverage and GEV. Conclusion: Our findings suggests that, both eyes closed and eyes open conditions were similar to each other in terms of stability and predominance of Maps
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Introducción: El electroencefalograma permite registrar la actividad eléctrica cerebral en estado de reposo y durante la ejecución de tareas cognitivas. Objetivo: Evaluar si la actividad cerebral, analizada como dinámica no lineal, se mantiene estable durante diferentes ventanas temporales en una condición basal con ojos cerrados. Métodos: Se realizaron registros con electroencefalograma durante dos minutos a 14 estudiantes universitarios varones. Posteriormente, se compararon las medias de índices de Hurst (H) en ventanas temporales de 60, 30 y 10 segundos. Resultados: Las medias de los índices H son estables a través de diferentes ventanas temporales en las regiones prefrontales, temporales y occipitales. Conclusiones: Los registros de electroencefalograma en condiciones basales con los ojos cerrados son válidos para comparar protocolos experimentales de resolución de problemas cognitivos utilizando el exponente de Hurst en los sujetos de la muestra y en otros con características similares(AU)
Introduction: Electroencephalography makes it possible to record brain electrical activity at rest and during the performance of cognitive tasks. Objective: Determine whether brain activity analyzed as nonlinear dynamics remains stable during various time windows in basal, eyes closed conditions. Methods: Electroencephalographic records of 14 male university students were taken during two minutes. Hurst's index means (H) were then compared in time windows of 60, 30 and 10 seconds. Results: H index means are stable throughout the various time windows in the prefrontal, temporal and occipital regions. Conclusions: Electroencephalographic records in basal, eyes closed conditions are valid to compare experimental protocols for cognitive problem solving using the Hurst exponent in subjects from the sample as well as others of similar characteristics(AU)
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Humans , Male , Young Adult , Rest , Electroencephalography , Students , Nonlinear DynamicsABSTRACT
BACKGROUND:One-legged standing with eyes closed is a method to test the muscle strength and the ability of body balance, it is considered to be an important quality indicator for evaluation of adults and elderly balancing capability in our country. A lot of works have been done in many provinces and cities, but there is a lack of in-depth studies. OBJECTIVE:To review the research progress of one-legged standing with eyes closed, to analyze its problem used in the physical fitness test and to prospect the future direction of the related researches. METHODS:A computer-based search on CNKI database and Elsevier database was undertaken to identify the article of balance capacity. The key words were“eyes closed and single legged standing, balance ability, physical fitness test”. Total y articles were searched and checked primarily, and those meeting the criteria were looked up. RESULTS AND CONCLUSION:The standard of one-legged standing with eyes closed for the male is higher than that for the female. Some elderly just stand for a short time in the test, and thus it is difficult to distinguish the balance ability. Elderly balance is significantly lower than that in young people. The same test method for adults and elderly people is employed, but whether it is scientific or not should be further studied. Various indicators in the test of one-legged standing with eyes closed have low correlation. For the above reasons, further studies should be made before the test of one-legged standing with eyes closed becomes a valuable measurement of the balance ability in the national physique.
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ObjectiveTo investigate the effects of eyes-closed (EC) and eyes-open (EO) EEG field powers on the auditory P300 evoke potentials.MethodsThe EEG was recorded in 12 healthy male college students (20 ～24 years) respectively in their eyes-closed and eyes-open states,and then the auditory P300 paradigm was performed.Results① Alpha band was distributed at the posterior-occipital area,while Alpha-1 (7.5～9.5 Hz) field power were EC as (2.62 ±0.81 ) μV2 and EO as ( 1.80 ±0.56) μV2,with statistical significance (P ＜ 0.01 ) ; Alpha-2 ( 10 ～ 12 Hz) field power were EC as ( 8.55 ± 1.85 ) μV2 and EO as (4.95 ± 1.59 )μV2,also with statistical significance (P＜0.05).②In P300,the Common stimulus elicited clear component N1 (90ms)and P2 (180ms) in the ERPs after stimulus,while there were no significant differences between EC and EO states.Correspondingly,the rare stimulus elicited clear component N2 (207 ms) and P3 (313 ms) in the ERPs after stimulus on-set.Comparing the differences of field potentials of the rare stimulus between the two states,N2field potential in EC ( (0.01 ± 0.71 ) μV) was smaller than that in EO ( ( - 2.13 ± 0.80 ) μV ),with statistical significance (P ＜ 0.05 ) ; while P3 field potential in the EC ( ( 4.16 ± 1.08 ) μV ) was smaller than that in EO ( (4.78 ± 1.20) μV),but without statistical significance (P ＞ 0.05 ).ConclusionThe alpha field power is higher in eyes-closed than in eyes-open state,while performing the same auditory P300 paradigm,significant reduction of field potential in the N2 component are observed in eyes-closed than in eyes-open state.
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@#ObjectiveTo investigate the changes of non-linear dynamics characteristic of EEG in patient with acute cerebral stroke under eyes closed state. MethodsEEG were recorded in 31 patients with acute cerebral infarction and 22 healthy volunteers under eyes closed state. Correlation dimension (D2) and Approximate Entropy (ApEn) were calculated for all subjects. ResultsD2 and ApEn of uninjured forehead cortex (FP1,FP2)reduced significantly in the group of cerebral infarction as compared with the group of normal control at eyes closed state. ConclusionDynamic analysis based on D2 and ApEn topographic maps might be helpful in understand the changes of mental functions after stroke, that can be used in the study of mental function.