Institute for Brain, Cognition and Behavior (IR3C), University of Barcelona, Barcelona, Spain..
Neuroimage. 2010 Jan 1;49(1):1038-44. doi: 10.1016/j.neuroimage.2009.07.059. Epub 2009 Jul 30.
Effective orienting of attention towards novel events is crucial for survival, particularly if they occur in a dangerous situation. This is why stimuli with emotional value are more efficient in capturing attention than neutral stimuli, and why the processing of unexpected novel stimuli is enhanced under a negative emotional context. Here we measured the phase-synchronization (PS) of gamma-band responses (GBR) from human EEG scalp-recordings during performance of a visual discrimination task in which task-irrelevant standard and novel sounds were presented in either a neutral or a negative emotional context, in order to elucidate the brain mechanisms by which emotion tunes the processing of novel events. Visual task performance was distracted by novel sounds, and this distraction was enhanced by the negative emotional context. Similarly, gamma PS was enhanced after novel as compared to standard sounds and it was also larger to auditory stimuli in the negative than in the neutral emotional context, reflecting the synchronization of neural networks for increasing of attentional processing. Remarkably, the larger PS increase of GBR after novel sounds in the negative as compared to the neutral emotional context over midline and right frontal regions reveals that a negative emotional context tunes novelty processing by means of the PS of brain activity in the gamma frequency band around 40 Hz in specific neural networks.
有效引导注意力关注新事件对生存至关重要，特别是如果这些事件发生在危险的情况下。这就是为什么具有情感价值的刺激比中性刺激更能有效地吸引注意力，以及为什么在负面情绪背景下，对意外新颖刺激的处理会增强。在这里，我们测量了人类 EEG 头皮记录中的伽马波段响应 (GBR) 的相位同步 (PS)，在执行视觉辨别任务期间，在中性或负面情绪背景下呈现与任务无关的标准和新颖声音，以阐明情绪调整新颖事件处理的大脑机制。视觉任务表现受到新颖声音的干扰，而负面情绪背景会增强这种干扰。同样，与标准声音相比，新颖声音后伽马 PS 增强，并且在负面情绪背景下，伽马 PS 对听觉刺激也更大，反映了神经网络的同步增强了注意力处理。值得注意的是，与中性情绪背景相比，负面情绪背景下新颖声音后的 GBR 相位同步增加更大，这表明负面情绪背景通过在特定神经网络中约 40 Hz 的伽马频带的脑活动的 PS 来调整新颖处理。
