Gurney K, Wright M J
Department of Psychology, University of Sheffield, UK.
Biol Cybern. 1996 Apr;74(4):349-58. doi: 10.1007/BF00194927.
We test the model of early visual processing introduced in the companion paper by simulating a range of psychophysical phenomena. We present new data concerning our ability to discriminate the speed of drifting gratings when spatiotemporally apertured in a variety of ways. We shall investigate the role played by the aperture in modifying the grating's behaviour from its idealisation as a pure Fourier component and show that this is not negligible. Other phenomena which we simulate and explain relate to the way perceived velocity is influenced by contrast and spatial frequency. Many of our explanations are couched in terms of the relative number of cells occurring within each locale of the Fourier domain. This use of the cell density map is a unifying concept and avoids the necessity for a range of separate mechanisms. We argue that a neurophysiologically detailed model is necessary in order to explain psychophysical data (Weber fractions) which vary over less than an order of magnitude, and small deviations from veridical encoding of velocity.
我们通过模拟一系列心理物理学现象，测试了在配套论文中引入的早期视觉处理模型。我们展示了关于在以各种方式进行时空孔径处理时，我们辨别漂移光栅速度能力的新数据。我们将研究孔径在将光栅行为从其作为纯傅里叶分量的理想化状态进行修改时所起的作用，并表明这一作用不可忽略。我们模拟和解释的其他现象涉及对比度和空间频率对感知速度的影响方式。我们的许多解释都是基于傅里叶域中每个区域内出现的细胞相对数量。细胞密度图的这种使用是一个统一的概念，避免了一系列单独机制的必要性。我们认为，为了解释变化小于一个数量级的心理物理学数据（韦伯分数）以及速度的真实编码的小偏差，需要一个神经生理学细节模型。
