Neural systems for orienting attention to the location of threat signals: An event-related fMRI study
Neural systems for orienting attention to the location of threat signals: An event-related fMRI study
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DOI：
10.1016/j.neuroimage.2005.12.034
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发表时间：
2006-06-01
期刊：
影响因子：
5.7
通讯作者：
Vuilleumier, Patrik
中科院分区：
文献类型：
--
作者：
Pourtois, Gilles;Schwartz, Sophie;Vuilleumier, Patrik
注意力可能会反射性地转移到感知到威胁的位置，但这些空间偏见是如何招募参与选择性注意其他方面的分布式额顶叶皮质网络的，目前尚不清楚。我们使用事件相关功能磁共振成像来确定在隐蔽定向任务中出现在同一位置的面孔的情绪表达如何影响大脑对中性视觉目标的反应。在每次试验中，简短地呈现两张脸，在每个上视野（一个中性的，一个情绪的，恐惧的或快乐的），然后是一个单方面的目标（一个小的水平或垂直的条）取代其中一张脸。参与者必须区分目标方向，显示在与情绪脸相同（有效）或相反（无效）的一面。包括有人脸但没有后续目标的试验（仅线索试验），以解开由于情绪线索对目标检测的影响而引起的激活。我们发现，与快乐面孔相比，恐惧面孔在双侧颞顶叶区和右侧枕顶叶皮层的反应增加，与后续目标和提示有效性无关。更重要的是，我们发现，当被试看到一张无效的恐惧面孔时，他们的顶叶内皮层和眶额叶皮层有选择性的调节，而当被试看到一张有效的恐惧面孔时，他们的右侧枕侧皮层的视觉反应也有所增加。而对于快乐的脸，没有观察到这样的影响。这些结果表明，恐惧的面孔可以作为外源性线索，通过增加纹外皮层对同一位置出现的后续目标的感觉处理，但也会通过改变IPS对无效线索目标的反应而产生脱离到另一个位置的成本。因此，负责将注意力导向情绪和非情绪刺激的神经机制在顶叶和视觉区域部分共享，但也部分不同。(c) 2005爱思唯尔公司版权所有。
Attention may reflexively shift towards the location of perceived threats, but it is still unclear how these spatial biases recruit the distributed fronto-parietal cortical networks involved in other aspects of selective attention. We used event-related fMRI to determine how brain responses to a neutral visual target are influenced by the emotional expression of faces appearing at the same location during a covert orienting task. On each trial, two faces were briefly presented, one in each upper visual field (one neutral and one emotional, fearful or happy), followed by a unilateral target (a small horizontal or vertical bar) replacing one of the faces. Participants had to discriminate the target orientation, shown on the same (valid) or opposite (invalid) side as the emotional face. Trials with faces but no subsequent target (cue-only trials) were included to disentangle activation due to emotional cues from their effects on target detection. We found increased responses in bilateral temporo-parietal areas and right occipito-parietal cortex for fearful faces relative to happy faces, unrelated to the subsequent target and cueing validity. More critically, we found a selective modulation of intraparietal and orbitofrontal cortex for targets following an invalid fearful face, as well as an increased visual response in right lateral occipital cortex for targets following a valid fearful face. No such effects were observed with happy faces. These results demonstrate that fearful faces can act as exogenous cues by increasing sensory processing in extrastriate cortex for a subsequent target presented at the same location, but also produce a cost in disengaging towards another location by altering the response of IPS to invalidly cued targets. Neural mechanisms responsible for orienting attention towards emotional vs. non-emotional stimuli are thus partly shared in parietal and visual areas, but also partly distinct. (c) 2005 Elsevier Inc. All rights reserved.