Başar E, Schürmann M, Başar-Eroglu C, Karakaş S
Institute of Physiology, Medical University Lübeck, Germany.
Int J Psychophysiol. 1997 Jun;26(1-3):5-29. doi: 10.1016/s0167-8760(97)00753-8.
The old concept stating that EEG alpha (10-Hz) activity reflects passive or idling states of the brain is giving way to modern views of 10-Hz oscillations in relation to diverse brain functions comprising sensory, motor, and memory processes: (1) Spontaneous alpha activity is not pure noise as shown by methods of chaos analysis. (2) Evoked alpha oscillations patterns (precisely time-locked to a stimulus; duration approx. 200-300 ms) depend on the modality of stimulation and the recording site. (3) Induced alpha oscillations are initiated by, but not closely time-locked to a stimulus. (4) 10-Hz oscillations are recorded in nervous systems of different complexities, from the human brain to isolated ganglia of invertebrates. The neural origins of 10-Hz oscillations are demonstrated by recordings at the cellular level. (5) Rather than trying to locate a unique alpha generator, it is preferable to assume that a 'diffuse and distributed alpha system' exists. A particular support for this hypothesis is given by stimulus-dependent hippocampal alpha responses in the cat brain. (6) The major physiological meaning of 10-Hz oscillations may be comparable to the putative universal role of gamma responses in brain signaling.
认为脑电图α（10赫兹）活动反映大脑被动或闲置状态的旧观念，正让位于关于10赫兹振荡与包括感觉、运动和记忆过程在内的多种脑功能相关的现代观点：（1）如混沌分析方法所示，自发α活动并非纯粹噪声。（2）诱发α振荡模式（精确地与刺激时间锁定；持续时间约200 - 300毫秒）取决于刺激方式和记录部位。（3）诱导α振荡由刺激引发，但与刺激时间并非紧密锁定。（4）从人类大脑到无脊椎动物的孤立神经节，在不同复杂程度的神经系统中都记录到了10赫兹振荡。10赫兹振荡的神经起源在细胞水平记录中得到证实。（5）与其试图定位一个独特的α发生器，不如假定存在一个“弥散且分布式的α系统”。猫脑中海马体对刺激的α反应为这一假说提供了特别支持。（6）10赫兹振荡的主要生理意义可能与γ反应在脑信号传导中假定的普遍作用相当。
