Schellekens Wouter, van Wezel Richard J A, Petridou Natalia, Ramsey Nick F, Raemaekers Mathijs
Brain Center Rudolf Magnus, UMC Utrecht, Str. 4.205, Postbus 85060, 3508 AB, Utrecht, The Netherlands.
Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
Brain Struct Funct. 2016 Mar;221(2):879-90. doi: 10.1007/s00429-014-0942-2. Epub 2014 Dec 2.
The current study investigates if early visual cortical areas, V1, V2 and V3, use predictive coding to process motion information. Previous studies have reported biased visual motion responses at locations where novel visual information was presented (i.e., the motion trailing edge), which is plausibly linked to the predictability of visual input. Using high-field functional magnetic resonance imaging (fMRI), we measured brain activation during predictable versus unpreceded motion-induced contrast changes during several motion stimuli. We found that unpreceded moving dots appearing at the trailing edge gave rise to enhanced BOLD responses, whereas predictable moving dots at the leading edge resulted in suppressed BOLD responses. Furthermore, we excluded biases in directional sensitivity, shifts in cortical stimulus representation, visuo-spatial attention and classical receptive field effects as viable alternative explanations. The results clearly indicate the presence of predictive coding mechanisms in early visual cortex for visual motion processing, underlying the construction of stable percepts out of highly dynamic visual input.
当前的研究调查了早期视觉皮层区域V1、V2和V3是否使用预测编码来处理运动信息。先前的研究报告称，在呈现新视觉信息的位置（即运动后缘）存在有偏差的视觉运动反应，这可能与视觉输入的可预测性有关。使用高场功能磁共振成像（fMRI），我们在几种运动刺激过程中，测量了可预测运动与无前兆运动诱发的对比度变化期间的大脑激活情况。我们发现，出现在后缘的无前兆移动点会引起增强的血氧水平依赖（BOLD）反应，而前缘的可预测移动点则导致BOLD反应受到抑制。此外，我们排除了方向敏感性偏差、皮层刺激表征的变化、视觉空间注意力和经典感受野效应作为可行的替代解释。结果清楚地表明，早期视觉皮层中存在用于视觉运动处理的预测编码机制，这是从高度动态的视觉输入中构建稳定感知的基础。
