Tononi G, Srinivasan R, Russell D P, Edelman G M
The Neurosciences Institute, 10640 John J. Hopkins Drive, San Diego, CA 92121, USA.
Proc Natl Acad Sci U S A. 1998 Mar 17;95(6):3198-203. doi: 10.1073/pnas.95.6.3198.
In binocular rivalry, a subject views two incongruent stimuli through each eye but consciously perceives only one stimulus at a time, with a switch in perceptual dominance every few seconds. To investigate the neural correlates of perceptual dominance in humans, seven subjects were recorded with a 148-channel magnetoencephalography array while experiencing binocular rivalry. A red vertical grating flickering at one frequency was presented to one eye through a red filter and a blue horizontal grating flickering at a different frequency was presented to the other eye through a blue filter. Steady-state neuromagnetic responses at the two frequencies were used as tags for the two stimuli and analyzed with high-resolution power spectra. It was found that a large number of channels showed peaks at both frequencies, arranged in a horseshoe pattern from posterior to anterior regions, whether or not the subject was consciously perceiving the corresponding stimulus. However, the amount of power at the stimulus frequency was modulated in relation to perceptual dominance, being lower in many channels by 50-85% when the subject was not conscious of that stimulus. Such modulation by perceptual dominance, although not global, was distributed to a large subset of regions showing stimulus-related responses, including regions outside visual cortex. The results demonstrate a correlation between the conscious perception of a visual stimulus and the synchronous activity of large populations of neurons as reflected by steady-state neuromagnetic responses.
在双眼竞争中，受试者通过每只眼睛观看两个不匹配的刺激，但每次只能有意识地感知到一个刺激，且每隔几秒感知优势就会发生切换。为了研究人类感知优势的神经关联，在七名受试者体验双眼竞争时，使用148通道脑磁图阵列对他们进行记录。通过红色滤光片向一只眼睛呈现以一种频率闪烁的红色垂直光栅，通过蓝色滤光片向另一只眼睛呈现以不同频率闪烁的蓝色水平光栅。两个频率下的稳态神经磁反应被用作两种刺激的标记，并通过高分辨率功率谱进行分析。结果发现，无论受试者是否有意识地感知相应的刺激，大量通道在两个频率上均显示出峰值，从后到前呈马蹄形排列。然而，刺激频率下的功率量与感知优势有关，当受试者未意识到该刺激时，许多通道中的功率会降低50 - 85%。这种由感知优势引起的调制虽然不是全局性的，但分布在显示与刺激相关反应的大部分区域，包括视觉皮层以外的区域。结果表明，视觉刺激的有意识感知与稳态神经磁反应所反映的大量神经元的同步活动之间存在关联。
