Kostandov É A, Cheremushkin E A, Ashkinazi M L
Zh Vyssh Nerv Deiat Im I P Pavlova. 2012 May-Jun;62(3):311-21.
A visual set was used as a model to study the influence of the increased memory load on the recognition of facial expression in 70 healthy adults. In order to additionally load the working memory, we lengthened the time gap between target (faces) and trigger stimuli. Such a lengthening from 1 to 8 s resulted in an increase of set plasticity (fewer mistakes in facial expression recognition). It also led to a reduction of the reaction time and less number of contrast illusions in recognition. We analyzed theta- and alpha-band EEG changes during individual segments of the time gap and suggested that repeated trials with a certain fixed interval between stimuli formed an inner representation of the interval duration. This inner representation up-regulates the visual attention in case of anticipation of a relevant event (stimulus) and down-regulates the attention when the stimulus is not expected. In case of the plastic set, the induced EEG synchronization in the alpha band is stronger in the trials with correct recognition in the middle of the inter-stimulus time gap. We think this synchronization reflects the action of the top-down cognitive control that suppresses the influence of irrelevant information on the brain activity. Theta-band dynamics in the inter-stimulus time gap can be associated with the emotional strain caused by the fact that a person had to retain in memory (for several seconds) the result of facial expression recognition.
以视觉组作为模型，研究增加记忆负荷对70名健康成年人面部表情识别的影响。为了额外增加工作记忆负荷，我们延长了目标（面部）与触发刺激之间的时间间隔。从1秒延长到8秒会导致组可塑性增加（面部表情识别错误减少）。这也导致反应时间缩短，识别中的对比错觉数量减少。我们分析了时间间隔各个阶段的θ波和α波段脑电图变化，并提出在刺激之间以一定固定间隔进行重复试验会形成间隔持续时间的内部表征。在预期相关事件（刺激）时，这种内部表征会上调视觉注意力，而在不预期刺激时则下调注意力。在可塑性组的情况下，在刺激间隔中间正确识别的试验中，α波段诱发的脑电图同步更强。我们认为这种同步反映了自上而下的认知控制作用，该控制抑制了无关信息对大脑活动的影响。刺激间隔中的θ波段动态可能与一个人必须在记忆中保留（几秒钟）面部表情识别结果所引起的情绪紧张有关。
