Blake Randolph, Sobel Kenith V, Gilroy Lee A
Vanderbilt Vision Research Center, Department of Psychology, Vanderbilt University, Nashville, TN 37203, USA.
Neuron. 2003 Aug 28;39(5):869-78. doi: 10.1016/s0896-6273(03)00495-1.
When the visual system is faced with conflicting or ambiguous stimulus information, visual perception fluctuates over time. We found that perceptual alternations are slowed when inducing stimuli move within the visual field, constantly engaging fresh, unadapted neural tissue. During binocular rivalry, dominance durations were longer when rival figures moved compared to when they were stationary, yielding lower alternation rates. Rate was not reduced, however, when observers tracked the moving targets, keeping the images on approximately the same retinal area. Alternations were reliably triggered when rival targets passed through a local region of the visual field preadapted to one of the rival targets. During viewing of a kinetic globe whose direction of rotation was ambiguous, observers experienced fewer alternations in perceived direction when the globe moved around the visual field or when the globe's axis of rotation changed continuously. Evidently, local neural adaptation is a key ingredient in the instability of perception.
当视觉系统面对相互冲突或模糊的刺激信息时，视觉感知会随时间波动。我们发现，当诱发刺激在视野内移动时，知觉交替会减慢，因为这会不断激活新的、未适应的神经组织。在双眼竞争中，与静止时相比，竞争图形移动时优势持续时间更长，交替率更低。然而，当观察者追踪移动目标，使图像保持在大致相同的视网膜区域时，交替率并未降低。当竞争目标穿过预先适应其中一个竞争目标的视野局部区域时，交替会被可靠地触发。在观看旋转方向模糊的动态球体时，当球体在视野中移动或其旋转轴不断变化时，观察者在感知方向上的交替次数较少。显然，局部神经适应是感知不稳定的关键因素。
