Department of Biology, Augsburg College, Minneapolis, MN 55454, USA.
Proc Natl Acad Sci U S A. 2010 Dec 28;107(52):22677-81. doi: 10.1073/pnas.1009857108. Epub 2010 Dec 13.
We studied visual perception using an annular random-dot motion stimulus called the racetrack. We recorded neural activity using magnetoencephalography while subjects viewed variants of this stimulus that contained no inherent motion or various degrees of embedded motion. Subjects reported seeing rotary motion during viewing of all stimuli. We found that, in the absence of any motion signals, patterns of brain activity differed between states of motion perception and nonperception. Furthermore, when subjects perceived motion, activity states within the brain did not differ across stimuli of different amounts of embedded motion. In contrast, we found that during periods of nonperception brain-activity states varied with the amount of motion signal embedded in the stimulus. Taken together, these results suggest that during perception the brain may lock into a stable state in which lower-level signals are suppressed.
我们使用一种称为“跑道”的环形随机点运动刺激来研究视觉感知。我们使用脑磁图记录了受试者在观看这种刺激的各种变体时的神经活动，这些变体没有内在的运动或不同程度的嵌入运动。受试者在观看所有刺激时都报告看到了旋转运动。我们发现，在没有任何运动信号的情况下，运动感知和非感知状态下的大脑活动模式不同。此外，当受试者感知运动时，大脑内的活动状态在不同嵌入运动量的刺激之间没有差异。相比之下，我们发现，在非感知期间，大脑活动状态随刺激中嵌入的运动信号量而变化。总的来说，这些结果表明，在感知过程中，大脑可能会锁定到一个稳定的状态，在这个状态下，较低层次的信号被抑制。
