[Changes of EEG frequency-fluctuation characteristics during visual workloads].
OBJECTIVE
To observe the changes of alpha-band frequency-fluctuation characteristics of EEG under visual task.


METHODS
Nineteen healthy right-handed male volunteers served as subjects, aged 24-32. EEG were recorded during rest (eyes-closed and eyes-open) and visual task, then analyzed using EEG frequency-fluctuation analysis system.


RESULTS
From eyes-closed to eyes-open, then to visual task state, the probability distribution characteristics of alpha-band frequency-fluctuation were significantly changed. The probability of 9 Hz and 10 Hz dominance decreased significantly, while the probability of 8 Hz and 11-13 Hz dominance increased significantly. The single component occupying absolute dominance was gradually transformed into the competition between these various components, and the lower frequency component in the front brain-areas gradually occupied dominance; meanwhile, the dominant fluctuation entropy increase significantly, the dominant fluctuation energy decreased significantly, and these processes showed obviously the brain-area related characteristics.


CONCLUSIONS
These changes of alpha-band frequency-fluctuation characteristics reflect the further enhancement of brain activities in the areas related to visual task. This method may be helpful in the study of visual workloads.
Institute of Space Medico-Engineering, Beijing, China.
Dong-xu
DX
Han
Chuan-dai
CD
Zhou
Yue-hong
YH
Liu
Li-wei
LW
Pang
D000328:Adult; D000513:Alpha Rhythm; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D006801:Humans; D008297:Male; D017711:Nonlinear Dynamics; D014796:Visual Perception / Q000502:physiology*