Changes in functional connectivity support conscious object recognition
Changes in functional connectivity support conscious object recognition
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DOI：
10.1016/j.neuroimage.2012.07.056
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发表时间：
2012-12-01
期刊：
影响因子：
5.7
通讯作者：
Haynes, John-Dylan
中科院分区：
文献类型：
--
作者：
Imamoglu, Fatma;Kahnt, Thorsten;Haynes, John-Dylan
介导有意识物体识别的大脑机制是什么？为了研究这个问题，有必要区分引起对刺激的有意识识别的大脑过程和其感官处理的其他相关过程。先前的功能磁共振成像研究已经确定了与有意识的视觉感知或识别相关的从条纹到高级感觉和前额叶区域的大规模大脑活动。然而，在这些区域之间的意识感知过程中，连接变化的可能作用很少被研究。在这里，我们使用功能磁共振成像和连通性分析，以及120张自定义生成的双色穆尼图像，直接评估对物体的有意识识别是否伴随着外皮层和前额叶区域之间功能耦合的动态变化。我们用两种不同的反应模式比较了19名天真受试者对物体的识别与不识别。我们发现，当有意识地识别物体时，层外皮层和背外侧前额叶皮层（DLPFC）之间的连通性增加。这种相互作用独立于用于报告意识识别的反应方式。此外，计算识别和未识别条件之间的格兰杰因果关系差显示，当被试识别物体时，前馈连通性比反馈连通性更强。我们认为，额叶和视觉脑区是一个功能网络的一部分，通过功能连接的变化来支持有意识的物体识别。(C) 2012爱思唯尔公司版权所有。
What are the brain mechanisms that mediate conscious object recognition? To investigate this question, it is essential to distinguish between brain processes that cause conscious recognition of a stimulus from other correlates of its sensoly processing. Previous fMRI studies have identified large-scale brain activity ranging from striate to high-level sensory and prefrontal regions associated with conscious visual perception or recognition. However, the possible role of changes in connectivity during conscious perception between these regions has only rarely been studied. Here, we used fMRI and connectivity analyses, together with 120 custom-generated, two-tone, Mooney images to directly assess whether conscious recognition of an object is accompanied by a dynamical change in the functional coupling between extrastriate cortex and prefrontal areas. We compared recognizing an object versus not recognizing it in 19 naive subjects using two different response modalities. We find that connectivity between the extrastriate cortex and the dorsolateral prefrontal cortex (DLPFC) increases when objects are consciously recognized. This interaction was independent of the response modality used to report conscious recognition. Furthermore, computing the difference in Granger causality between recognized and not recognized conditions reveals stronger feedforward connectivity than feedback connectivity when subjects recognized the objects. We suggest that frontal and visual brain regions are part of a functional network that supports conscious object recognition by changes in functional connectivity. (C) 2012 Elsevier Inc. All rights reserved.