Decoding perceptual awareness across the brain with a no-report fMRI masking paradigm
Decoding perceptual awareness across the brain with a no-report fMRI masking paradigm
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DOI：
10.1016/j.cub.2022.07.068
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发表时间：
2022-10-10
期刊：
影响因子：
9.2
通讯作者：
Cohen, Michael A.
中科院分区：
文献类型：
--
作者：
Hatamimajoumerd, Elaheh;Murty, N. Apurva Ratan;Cohen, Michael A.
感知觉是在大脑的感觉区域还是在更高层次的区域（例如，额叶（frontal lobe）？为了回答这个问题，研究人员传统上比较了观察者报告意识到与不知道刺激时的神经活动。然而，目前尚不清楚所产生的激活是否与刺激的有意识感知或与报告该刺激相关的感知后过程相关。为了解决这一限制，我们在视觉掩蔽范式中使用了报告和无报告条件，同时使用功能性MRI（fMRI）对参与者进行扫描。我们发现，在额叶的可见刺激的整体单变量反应是强大的报告条件下，但在无报告条件下消失。然而，使用多变量模式，我们仍然可以在两种情况下解码刺激是否通过大脑（包括额叶）达到有意识的意识。这些结果有助于调和最近文献中的关键差异，并为识别与感知意识相关的神经机制提供了一条前进的道路。
Does perceptual awareness arise within the sensory regions of the brain or within higher-level regions (e.g., the frontal lobe)? To answer this question, researchers traditionally compare neural activity when observers report being aware versus being unaware of a stimulus. However, it is unclear whether the resulting activations are associated with the conscious perception of the stimulus or the post-perceptual processes associated with reporting that stimulus. To address this limitation, we used both report and no-report conditions in a visual masking paradigm while participants were scanned using functional MRI (fMRI). We found that the overall univariate response to visible stimuli in the frontal lobe was robust in the report condition but disappeared in the no-report condition. However, using multivariate patterns, we could still decode in both conditions whether a stimulus reached conscious awareness across the brain, including in the frontal lobe. These results help reconcile key discrepancies in the recent literature and provide a path forward for identifying the neural mechanisms associated with perceptual awareness.