Fründ Ingo, Wichmann Felix A, Macke Jakob H
Bernstein Center for Computational Neuroscience, Technical University Berlin, GermanyCenter for Vision Research, York University, Toronto, ON, Canada.
Neural Information Processing Group, Eberhard Karls Universität, Max Planck Institute for Intelligent Systems, Bernstein Center for Computational Neuroscience, Tübingen, Germany.
J Vis. 2014 Jun 18;14(7):9. doi: 10.1167/14.7.9.
In the perceptual sciences, experimenters study the causal mechanisms of perceptual systems by probing observers with carefully constructed stimuli. It has long been known, however, that perceptual decisions are not only determined by the stimulus, but also by internal factors. Internal factors could lead to a statistical influence of previous stimuli and responses on the current trial, resulting in serial dependencies, which complicate the causal inference between stimulus and response. However, the majority of studies do not take serial dependencies into account, and it has been unclear how strongly they influence perceptual decisions. We hypothesize that one reason for this neglect is that there has been no reliable tool to quantify them and to correct for their effects. Here we develop a statistical method to detect, estimate, and correct for serial dependencies in behavioral data. We show that even trained psychophysical observers suffer from strong history dependence. A substantial fraction of the decision variance on difficult stimuli was independent of the stimulus but dependent on experimental history.We discuss the strong dependence of perceptual decisions on internal factors and its implications for correct data interpretation.
在感知科学中，实验者通过用精心构建的刺激探测观察者来研究感知系统的因果机制。然而，长期以来人们都知道，感知决策不仅由刺激决定，还受内部因素影响。内部因素可能导致先前的刺激和反应对当前试验产生统计影响，从而产生序列依赖性，这使得刺激与反应之间的因果推断变得复杂。然而，大多数研究并未考虑序列依赖性，而且它们对感知决策的影响程度尚不清楚。我们推测，这种忽视的一个原因是一直没有可靠的工具来量化它们并校正其影响。在此，我们开发了一种统计方法来检测、估计和校正行为数据中的序列依赖性。我们表明，即使是训练有素的心理物理学观察者也存在强烈的历史依赖性。在困难刺激上，相当一部分决策方差与刺激无关，而是取决于实验历史。我们讨论了感知决策对内部因素的强烈依赖性及其对正确数据解释的影响。
