Tang Yingying, Li Yingjie, Wang Jijun, Tong Shanbao, Li Hui, Yan Jing
Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:1717-20. doi: 10.1109/IEMBS.2011.6090492.
Cognitive control of emotion plays an important role in maintaining emotional stability in people's daily life. However, the neural mechanism remains unclear. This study examined the induced gamma activity in response to emotional expressions which was associated with the cognitive regulation. Electroencephalogram (EEG) was recorded in fifteen normal subjects when detecting emotional expressions. The mean energy was estimated using time-frequency representations in two gamma bands, low gamma band (25-50 Hz) and high gamma band (50-70 Hz), and eight time windows from 0 to 800 ms after the stimulus onset. Two typical gamma activities were observed: (1) the early gamma activity in the 100-200 ms time window was attenuated along with the increased detection difficulty, reflecting the bottom-up attention regulation; (2) the late gamma activity after 400 ms post-stimulus was enhanced with the increased detection difficulty, reflecting the top-down cognitive control. The characteristics of the induced early gamma activity distinguished different mechanisms of attention regulation in the early stage for detecting the negative expression and detecting the positive one. Our study suggested the induced gamma activity was a useful tool to uncover the mechanism of cognitive control of emotion.
情绪的认知控制在人们日常生活中维持情绪稳定方面发挥着重要作用。然而，其神经机制仍不清楚。本研究检测了与认知调节相关的、对情绪表达产生的诱发伽马活动。在15名正常受试者检测情绪表达时记录脑电图（EEG）。使用时频表征在两个伽马频段，即低伽马频段（25 - 50赫兹）和高伽马频段（50 - 70赫兹）以及刺激开始后0至800毫秒的八个时间窗内估计平均能量。观察到两种典型的伽马活动：（1）在100 - 200毫秒时间窗内的早期伽马活动随着检测难度增加而减弱，反映自下而上的注意力调节；（2）刺激后400毫秒后的晚期伽马活动随着检测难度增加而增强，反映自上而下的认知控制。诱发的早期伽马活动特征区分了在检测负面表情和正面表情早期阶段注意力调节的不同机制。我们的研究表明，诱发伽马活动是揭示情绪认知控制机制的有用工具。
