Perceptual moments of conscious visual experience inferred from oscillatory brain activity
Perceptual moments of conscious visual experience inferred from oscillatory brain activity
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DOI：
10.1073/pnas.0508972103
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发表时间：
2006-04-04
影响因子：
11.1
通讯作者：
Schyns, PG
中科院分区：
文献类型：
--
作者：
Smith, ML;Gosselin, F;Schyns, PG
大脑中同步振荡神经元放电的瞬时周期被认为支持潜藏在意识视觉体验下的离散感知时刻。然而，这些感知时刻的信息内容仍然是对意识理解的一个关键挑战。我们在四位观察者中发现了这一信息内容，他们有意识地看到了对模棱两可的达利绘画奴隶市场和消失的伏尔泰半身像的每一种解释。对于每个单独的观察者，我们分离出他们对输入的公开判断所依据的刺激空间频率(SF)特征，即“修女”和“伏尔泰”。在刺激开始和显性反应之间每隔2毫秒，我们得出观察者的振荡脑活动(在theta、α和β带宽上)对这些SF特征的敏感度。然后，在每个带宽中，我们估计与知觉时刻相对应的知觉特定SF特征被最大限度地整合的时刻(在刺激开始和知觉判断之间)。我们表明，中心顶层的β振荡支持修女有意识感知的知觉时刻，而theta振荡支持伏尔泰的感知。对于这两种感知，我们揭示了这些感知时刻的具体信息内容。
Transient periods of synchronized oscillating neuronal discharges in the brain have been proposed to support the discrete perceptual moments underlying conscious visual experience. However, the information content of these perceptual moments remains a critical challenge to the understanding of consciousness. We uncovered this information content in four observers who consciously perceived each interpretation of the ambiguous Dali painting Slave Market with the Disappearing Bust of Voltaire. For each individual observer, we isolated the stimulus spatial frequency (SF) features underlying their overt judgments of the input as '' the nuns '' and '' Voltaire ''. Every 2 ms between stimulus onset and overt response, we derived the sensitivity of the observer's oscillatory brain activity (in the theta, alpha, and beta bandwidths) to these SF features. Then, in each bandwidth, we estimated the moments (between stimulus onset and perceptual judgment) when perception-specific SF features were maximally integrated, corresponding to perceptual moments. We show that the centroparietal beta oscillations support perceptual moments underlying the conscious perception of the nuns, whereas theta oscillations support the perception of Voltaire. For both perceptions, we reveal the specific information content of these perceptual moments.