Denison Rachel N, Piazza Elise A, Silver Michael A
Helen Wills Neuroscience Institute, University of California Berkeley, CA, USA.
Front Hum Neurosci. 2011 Dec 15;5:166. doi: 10.3389/fnhum.2011.00166. eCollection 2011.
it has been proposed that the brain continuously generates predictions about forthcoming sensory information. However, little is known about how prediction contributes to the selection of a conscious percept from among competing alternatives. Here, we used binocular rivalry to investigate the effects of prediction on perceptual selection. In binocular rivalry, incompatible images presented to the two eyes result in a perceptual alternation between the images, even though the visual stimuli remain constant. If predictive signals influence the competition between neural representations of rivalrous images, this influence should generate a bias in perceptual selection that depends on predictive context. To manipulate predictive context, we developed a novel binocular rivalry paradigm in which rivalrous test images were immediately preceded by a sequence of context images presented identically to the two eyes. One of the test images was consistent with the preceding image sequence (it was the expected next image in the series), and the other was inconsistent (non-predicted). We found that human observers were more likely to perceive the consistent image at the onset of rivalry, suggesting that predictive context biased selection in favor of the predicted percept. This prediction effect was distinct from the effects of adaptation to stimuli presented before the binocular rivalry test. In addition, perceptual reports were speeded for predicted percepts relative to non-predicted percepts. These results suggest that predictive signals related to visual stimulus history exist at neural sites that can bias conscious perception during binocular rivalry. Our paradigm provides a new way to study how prior information and incoming sensory information combine to generate visual percepts.
有人提出大脑会持续生成关于即将到来的感觉信息的预测。然而，对于预测如何在相互竞争的备选方案中促成有意识知觉的选择，我们却知之甚少。在此，我们利用双眼竞争来研究预测对知觉选择的影响。在双眼竞争中，呈现给双眼的不兼容图像会导致图像之间的知觉交替，即便视觉刺激保持不变。如果预测信号影响相互竞争图像的神经表征之间的竞争，那么这种影响应该会在知觉选择中产生一种依赖于预测背景的偏差。为了操控预测背景，我们开发了一种新颖的双眼竞争范式，在该范式中，相互竞争的测试图像之前会紧接着呈现一系列双眼所见完全相同的背景图像。其中一幅测试图像与之前的图像序列一致（它是该序列中预期的下一幅图像），而另一幅则不一致（未被预测到）。我们发现，人类观察者在竞争开始时更有可能知觉到一致的图像，这表明预测背景使选择产生偏差，从而有利于被预测的知觉。这种预测效应不同于对双眼竞争测试之前呈现的刺激的适应效应。此外，相对于未被预测到的知觉，对被预测到的知觉的知觉报告速度更快。这些结果表明，与视觉刺激历史相关的预测信号存在于能够在双眼竞争期间使有意识知觉产生偏差的神经部位。我们的范式提供了一种新方法，用于研究先验信息和传入的感觉信息如何结合以生成视觉知觉。
