Marko H
Biol Cybern. 1981;39(2):111-23. doi: 10.1007/BF00336737.
By considering only the modulation transfer functions of stationary, uniformly moved, and time modulated sinusoidal gratings it is possible to derive a simple model, the "z-model", for the spatio-temporal frequency behaviour of one-dimensional patterns. The transmission function of this model is a band pass function of a single coordinate z, which is a quadratic form of the spatial and temporal frequencies (rotational symmetry with respect to space and time). The model is determined by only three constants. Optionally a time phase which accounts for delay and phase distortion can be added. This model can also be derived from reaction time measurements for switched on sinusoidal gratings. With this model the response of a wide variety of spaito-temporal patterns have been calculated and compared with measured threshold data. For two-dimensional patterns orientational filtering has to be added to the model leading to a further parameter. This model predicts satisfactorily the threshold modulation for a great variety of arbitrary spaito-temporal patterns. However the absolute threshold value for aperiodic transient patterns differs slightly in direction of smaller sensitivity as compared with periodic stationary patterns. This suggests that the peak detection scheme usually used in threshold detection modeling should be replaced by an integrative mechanism.
通过仅考虑静止、匀速移动和时间调制的正弦光栅的调制传递函数，可以推导出一个简单模型，即“z模型”，用于描述一维图案的时空频率行为。该模型的传递函数是单个坐标z的带通函数，它是空间和时间频率的二次形式（关于空间和时间具有旋转对称性）。该模型仅由三个常数确定。还可以选择添加一个考虑延迟和相位失真的时间相位。该模型也可以从正弦光栅开启时的反应时间测量中推导出来。利用这个模型，已经计算了各种时空图案的响应，并与测量的阈值数据进行了比较。对于二维图案，必须在模型中添加方向滤波，这会导致另一个参数。该模型令人满意地预测了各种任意时空图案的阈值调制。然而，与周期性静止图案相比，非周期性瞬态图案的绝对阈值在灵敏度较小的方向上略有不同。这表明阈值检测建模中通常使用的峰值检测方案应该被一种积分机制所取代。
