Flaisch Tobias, Imhof Martin, Schmälzle Ralf, Wentz Klaus-Ulrich, Ibach Bernd, Schupp Harald T
Department of Psychology, University of Konstanz Konstanz, Germany.
Department of Radiology, Kantonsspital Münsterlingen Münsterlingen, Switzerland.
Front Psychol. 2015 Dec 18;6:1861. doi: 10.3389/fpsyg.2015.01861. eCollection 2015.
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.
本研究利用功能磁共振成像（fMRI）来检验在不同的显性和隐性注意需求下同时呈现的情绪刺激的神经加工过程。具体而言，在不同的试验中，参与者指出图片或单词的类别。单词被放置在图片的中心位置，并且在快速事件相关设计中，图片 - 单词复合刺激呈现1500毫秒。结果揭示了任务和情绪的显著主效应：图片分类任务在视觉、顶叶、颞叶、额叶和皮层下区域引发了强烈的激活；单词分类任务仅在左侧纹外皮层引起激活增加。此外，除了复制关于情绪图片和单词加工的关键发现外，结果还指出了单词的语义 - 情感和感觉 - 知觉过程的分离：无论任务如何，情绪单词都激活了左半球的语义 - 情感网络，而当单词叠加在色情图像上时，与明确关注单词相关的左侧纹外皮层活动增加减弱。最后，我们在背侧视觉联合区域、下顶叶、背外侧和内侧前额叶皮层观察到图片类别和任务之间的显著交互作用：在单词分类任务中，与浪漫图片相比，当单词叠加在色情图片上时，这些区域的激活增加。在图片分类任务中，与浪漫图片相比，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影响了致力于控制与任务相关的单词或图片加工的脑区。将结合强制性刺激加工与任务相关注意控制机制的相互作用来讨论这些发现。
