Detection of the response of cortical rhythmic activities and extraction of the internal state such as affection and stress

我们进行了脑磁图(MEG)测量，而正常受试者正在观看一组选定的图片，并为这些图片建立了情感值。在测量过程中，以与视觉或听觉节律活动的频率匹配的刺激率(或其谐波)向受试者传递图像帧上的闪烁光刺激或重复的声音刺激。稳态反应的结果表明，消极情绪图片的反应幅度比积极情绪图片的反应幅度增大。我们认为，节律性神经活动可以作为情感或认知负荷等内在状态的客观测量。

We have conducted MEG (magnetoencephalography) measurements while normal subjects were watching a set of selected pictures for which affection values were established. During the measurement, either flicker-light stimulation at the frame of pictures or repetitive sound stimuli was delivered to the subjects at a stimulation rate that (or its harmonic) was matched to the frequency of visual or auditory rhythmic activity. Results of the steady state response indicated augmentation of the response-amplitude for negative than positive affective pictures. We suggest that the rhythmic neural activities could serve as objective measures of internal condition such as affection or cognitive load.