Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada.
Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada; Neurosciences and Mental Health Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Psychology, University of Toronto, Toronto, Ontario, Canada.
PLoS One. 2014 Apr 11;9(4):e93753. doi: 10.1371/journal.pone.0093753. eCollection 2014.
It is well known that we continuously filter incoming sensory information, selectively allocating attention to what is important while suppressing distracting or irrelevant information. Yet questions remain about spatiotemporal patterns of neural processes underlying attentional biases toward emotionally significant aspects of the world. One index of affectively biased attention is an emotional variant of an attentional blink (AB) paradigm, which reveals enhanced perceptual encoding for emotionally salient over neutral stimuli under conditions of limited executive attention. The present study took advantage of the high spatial and temporal resolution of magnetoencephalography (MEG) to investigate neural activation related to emotional and neutral targets in an AB task. MEG data were collected while participants performed a rapid stimulus visual presentation task in which two target stimuli were embedded in a stream of distractor words. The first target (T1) was a number and the second (T2) either an emotionally salient or neutral word. Behavioural results replicated previous findings of greater accuracy for emotionally salient than neutral T2 words. MEG source analyses showed that activation in orbitofrontal cortex, characterized by greater power in the theta and alpha bands, and dorsolateral prefrontal activation were associated with successful perceptual encoding of emotionally salient relative to neutral words. These effects were observed between 250 and 550 ms, latencies associated with discrimination of perceived from unperceived stimuli. These data suggest that important nodes of both emotional salience and frontoparietal executive systems are associated with the emotional modulation of the attentional blink.
众所周知，我们不断地过滤传入的感官信息，有选择地将注意力集中在重要的事情上，同时抑制分散注意力或不相关的信息。然而，关于注意偏向于世界上情感重要方面的神经过程的时空模式仍存在疑问。注意偏向的一个指标是注意瞬脱（AB）范式的情感变体，它揭示了在有限的执行注意条件下，对情感上显著的刺激比中性刺激有更强的感知编码。本研究利用脑磁图（MEG）的高空间和时间分辨率，研究了 AB 任务中与情感和中性目标相关的神经激活。当参与者在快速呈现刺激的视觉呈现任务中执行任务时，MEG 数据被收集，其中两个目标刺激嵌入在分散注意力的单词流中。第一个目标（T1）是一个数字，第二个目标（T2）是一个情感上显著的或中性的词。行为结果复制了以前的发现，即情感上显著的 T2 词比中性词的准确性更高。MEG 源分析显示，眶额皮层的激活与theta 和 alpha 波段的功率增加以及背外侧前额叶的激活有关，这与成功地感知到情感上显著的词与中性词有关。这些效应在 250 到 550 毫秒之间观察到，与感知到与未感知到的刺激的区分有关。这些数据表明，情感显著性和额顶执行系统的重要节点都与注意瞬脱的情感调节有关。
