Neural signature of the conscious processing of auditory regularities
Neural signature of the conscious processing of auditory regularities
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DOI：
10.1073/pnas.0809667106
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发表时间：
2009-02-03
影响因子：
11.1
通讯作者：
Naccache, Lionel
中科院分区：
文献类型：
--
作者：
Bekinschtein, Tristan A.;Dehaene, Stanislas;Naccache, Lionel
有意识的处理过程能从神经生理学的测量中推断出来吗？一些模型规定，跨时间主动维持知觉表征需要意识。利用这一假设，我们设计了一个听觉范式，评估大脑的反应，无论是局部的时间或全球跨越几秒钟的时间间隔的侵犯。局部侵犯导致听觉皮层的早期反应，独立的注意力或存在的并发视觉任务，而全球的侵犯导致一个迟来的和空间分布的反应，只有当受试者注意和意识到的侵犯。我们可以使用功能性MRI以及头皮和脑内事件相关电位来检测个体受试者的整体效应。8名意识障碍的非沟通患者的记录证实，只有有意识的个人提出了一个全球性的影响。这些观察结果表明，整体效应的存在是有意识加工的一个标志，尽管在没有意识到整体听觉刺激的有意识受试者中可能不存在。因此，这种简单的电生理标记物可以作为一种有用的临床工具。
Can conscious processing be inferred from neurophysiological measurements? Some models stipulate that the active maintenance of perceptual representations across time requires consciousness. Capitalizing on this assumption, we designed an auditory paradigm that evaluates cerebral responses to violations of temporal regularities that are either local in time or global across several seconds. Local violations led to an early response in auditory cortex, independent of attention or the presence of a concurrent visual task, whereas global violations led to a late and spatially distributed response that was only present when subjects were attentive and aware of the violations. We could detect the global effect in individual subjects using functional MRI and both scalp and intracerebral event-related potentials. Recordings from 8 noncommunicating patients with disorders of consciousness confirmed that only conscious individuals presented a global effect. Taken together these observations suggest that the presence of the global effect is a signature of conscious processing, although it can be absent in conscious subjects who are not aware of the global auditory regularities. This simple electrophysiological marker could thus serve as a useful clinical tool.