[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.
Han
Dong-xu
DX
Institute of Space Medico-Engineering, Beijing, China.
Zhou
Chuan-dai
CD
Liu
Yue-hong
YH
Pang
Li-wei
LW
D000328:Adult; D000513:Alpha Rhythm; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D006801:Humans; D008297:Male; D017711:Nonlinear Dynamics; D014796:Visual Perception / Q000502:physiology*