Kostandov Ē A, Cheremushkin E A, Ashkinazi M L, Iakovenko I A
Zh Vyssh Nerv Deiat Im I P Pavlova. 2011 Nov-Dec;61(6):675-87.
A certain alpha-band EEG dynamics was revealed in healthy adults (n = 16) at the interval between a warning and a target stimulus in a simple visuospatial task (subjects were instructed to locate a specific letter in the table of letters). Two series of experiment--either with a 2-sec or a 9-sec inter-stimulus interval were conducted, each consisting of 60 trials. In both series, we observed an induced desynchronization of low alpha (8-10 Hz) at the first second after the warning stimulus and its desynchronization just before the target stimulus. In series with a 9-sec inter-stimulus interval at the 4-6 s of it we observed an alpha-band synchronization, especially distinct in high alpha (10.5-13 Hz). This synchronization gradually reduced towards the end of the inter-stimulus interval. We consider the above changes in alpha-band spectral power during the inter-stimulus interval to be induced by "inner impulsations" caused by an internal representation (set) of the stimuli time-sequence. Changes in the level of cognitive control during the inter-stimulus interval cause increases and decreases in fronto-thalamic system activity, which are manifested in changes of alpha-band spectral power. Analysis of theta-band dynamics suggests that cortico-hippocampal system doesn't participate in this process.
在一项简单的视觉空间任务（受试者被要求在字母表中找出特定字母）中，研究人员在健康成年人（n = 16）身上发现，在警告刺激和目标刺激之间的间隔期，特定的阿尔法波段脑电图动态变化。实验分为两个系列，刺激间隔分别为2秒或9秒，每个系列由60次试验组成。在两个系列中，我们都观察到在警告刺激后的第一秒出现低阿尔法（8 - 10赫兹）诱导去同步化，以及在目标刺激前其去同步化。在刺激间隔为9秒的系列中，在间隔的4 - 6秒时，我们观察到阿尔法波段同步化，在高阿尔法（10.5 - 13赫兹）中尤为明显。这种同步化在刺激间隔结束时逐渐减弱。我们认为，刺激间隔期间阿尔法波段频谱功率的上述变化是由刺激时间序列的内部表征（定势）引起的“内部冲动”所诱发的。刺激间隔期间认知控制水平的变化导致额丘脑系统活动的增加和减少，这表现为阿尔法波段频谱功率的变化。对θ波段动态的分析表明，皮质 - 海马系统不参与这一过程。
