视觉作业负荷下脑波频率涨落特征的变化特点

目的考察静态和视觉作业负荷下的脑波α段频率涨落特征、以及视觉作业相关的变化特点。方法记录19名青年男性静态(闭眼及睁眼)和执行视觉作业过程中的EEG，应用脑波频率涨落分析技术分析状态相关的α段频率涨落特征及变化特点。结果由闭眼、睁眼至视觉作业状态，α段频率涨落优势概率分布特征显著改变，9Hz、10Hz优势下降，8Hz、11～13Hz优势上升，具有绝对优势的主涨落成分逐渐为多成分竞争所代替，前部脑区较慢成分逐渐居于优势；各脑区α段优势涨落熵值显著增加，优势涨落能量逐渐显著降低，且其增加／下降过程均具有明显的脑区性。结论脑波α段频率涨落特征指标的变化反映了视觉作业下相关脑区活动的进一步增强，表明该技术可应用于视觉作业负荷的研究。

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. Method: 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. Result: 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. Conclusion: 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.