Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing.
Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing.
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DOI：
10.3389/fpsyg.2015.01861
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发表时间：
2015
影响因子：
3.8
通讯作者：
Schupp HT
中科院分区：
文献类型：
--
作者：
Flaisch T;Imhof M;Schmälzle R;Wentz KU;Ibach B;Schupp HT
本研究利用功能磁共振成像（fMRI）研究了不同外显和内隐注意要求下并发情绪刺激的神经加工过程。具体来说，在单独的试验中，参与者指出图片或文字的类别。在快速事件相关设计中，将单词置于图片的中心，并在1500 ms内呈现图片-单词复合刺激。结果表明，任务和情绪的主效应显著：图像分类任务在视觉区、顶叶区、颞叶区、额叶区和皮层下区均有较强的激活；单词分类任务仅在左侧纹状外皮层引起激活增加。此外，除了复制有关情感图片和文字处理的关键发现外，研究结果还指出了文字的语义-情感和感觉-知觉过程的分离：尽管与任务无关的情感词汇涉及左半球的语义-情感网络，但当单词覆盖在色情图像上时，与明确关注单词相关的左外皮层活动的增加减少了。最后，我们观察到图片类别和任务之间在背侧视觉联想区、顶叶下皮层、背外侧皮层和内侧前额叶皮层中存在显著的相互作用：在单词分类任务中，当单词覆盖在色情图片上时，这些区域的激活程度比覆盖在浪漫图片上时有所增加。在图片分类任务中，与对浪漫图片进行分类相比，对色情图片进行分类时，这些区域的活动相对减少。因此，图片的情绪强度强烈地影响了负责控制与任务相关的文字或图像处理的大脑区域。这些发现讨论了强制性刺激处理与任务相关的注意控制机制的相互作用。
The present study utilized functional magnetic resonance imaging (fMRI) to examine the neural processing of concurrently presented emotional stimuli under varying explicit and implicit attention demands. Specifically, in separate trials, participants indicated the category of either pictures or words. The words were placed over the center of the pictures and the picture-word compound-stimuli were presented for 1500 ms in a rapid event-related design. The results reveal pronounced main effects of task and emotion: the picture categorization task prompted strong activations in visual, parietal, temporal, frontal, and subcortical regions; the word categorization task evoked increased activation only in left extrastriate cortex. Furthermore, beyond replicating key findings regarding emotional picture and word processing, the results point to a dissociation of semantic-affective and sensory-perceptual processes for words: while emotional words engaged semantic-affective networks of the left hemisphere regardless of task, the increased activity in left extrastriate cortex associated with explicitly attending to words was diminished when the word was overlaid over an erotic image. Finally, we observed a significant interaction between Picture Category and Task within dorsal visual-associative regions, inferior parietal, and dorsolateral, and medial prefrontal cortices: during the word categorization task, activation was increased in these regions when the words were overlaid over erotic as compared to romantic pictures. During the picture categorization task, activity in these areas was relatively decreased when categorizing erotic as compared to romantic pictures. Thus, the emotional intensity of the pictures strongly affected brain regions devoted to the control of task-related word or picture processing. These findings are discussed with respect to the interplay of obligatory stimulus processing with task-related attentional control mechanisms.