CNRS, UMR5549, Centre de Recherche Cerveau et Cognition, Faculté de Médecine de Purpan, Toulouse, France; Université Paul Sabatier, Toulouse, France.
CNRS, UMR5549, Centre de Recherche Cerveau et Cognition, Faculté de Médecine de Purpan, Toulouse, France; Université Paul Sabatier, Toulouse, France.
Cell Rep. 2019 Jan 8;26(2):374-380.e4. doi: 10.1016/j.celrep.2018.12.058.
EEG reverse-correlation techniques have revealed that visual information processing entails a ∼10-Hz (alpha) occipital response that reverberates sensory inputs up to 1 s. However, the spatial distribution of these perceptual echoes remains unknown: are they synchronized across the brain, or do they propagate like a traveling wave? Here, in two experiments with varying stimulus locations, we demonstrate the systematic phase propagation of perceptual echoes. A single stimulation in the upper visual field produced an "echo traveling wave" propagating from posterior to frontal sensors. The simultaneous presentation of two independent stimuli in separate visual hemifields produced two superimposed traveling waves propagating in opposite directions. Strikingly, in each sensor, the phase of the two echoes differed, with a phase advance for the contralateral stimulus. Thus, alpha traveling waves sweep across the human brain, encoding stimulus position in the phase domain, in line with the 70-year-old "cortical scanning" hypothesis (Pitts and McCulloch, 1947).
EEG 负相关技术表明，视觉信息处理需要一个约 10Hz（阿尔法）的枕部反应，该反应可以将感觉输入回响长达 1 秒。然而，这些感知回波的空间分布尚不清楚：它们是在整个大脑中同步的，还是像行波一样传播？在这里，我们在两个具有不同刺激位置的实验中证明了感知回波的系统相位传播。在上部视野中的单个刺激产生了从后向前部传感器传播的“回声行波”。在两个独立的刺激分别在两个视觉半视野中同时呈现产生了两个传播方向相反的叠加行波。引人注目的是，在每个传感器中，两个回波的相位不同，对于对侧刺激有相位超前。因此，阿尔法行波在人脑上扫过，以相位域编码刺激位置，符合 70 年前的“皮层扫描”假说（Pitts 和 McCulloch，1947）。
