Frishman L J, Freeman A W, Troy J B, Schweitzer-Tong D E, Enroth-Cugell C
J Gen Physiol. 1987 Apr;89(4):599-628. doi: 10.1085/jgp.89.4.599.
Spatiotemporal frequency responses were measured at different levels of light adaptation for cat X and Y retinal ganglion cells. Stationary sinusoidal luminance gratings whose contrast was modulated sinusoidally in time or drifting gratings were used as stimuli. Under photopic illumination, when the spatial frequency was held constant at or above its optimum value, an X cell's responsivity was essentially constant as the temporal frequency was changed from 1.5 to 30 Hz. At lower temporal frequencies, responsivity rolled off gradually, and at higher ones it rolled off rapidly. In contrast, when the spatial frequency was held constant at a low value, an X cell's responsivity increased continuously with temporal frequency from a very low value at 0.1 Hz to substantial values at temporal frequencies higher than 30 Hz, from which responsivity rolled off again. Thus, 0 cycles X deg-1 became the optimal spatial frequency above 30 Hz. For Y cells under photopic illumination, the spatiotemporal interaction was even more complex. When the spatial frequency was held constant at or above its optimal value, the temporal frequency range over which responsivity was constant was shorter than that of X cells. At lower spatial frequencies, this range was not appreciably different. As for X cells, 0 cycles X deg-1 was the optimal spatial frequency above 30 Hz. Temporal resolution (defined as the high temporal frequency at which responsivity had fallen to 10 impulses X s-1) for a uniform field was approximately 95 Hz for X cells and approximately 120 Hz for Y cells under photopic illumination. Temporal resolution was lower at lower adaptation levels. The results were interpreted in terms of a Gaussian center-surround model. For X cells, the surround and center strengths were nearly equal at low and moderate temporal frequencies, but the surround strength exceeded the center strength above 30 Hz. Thus, the response to a spatially uniform stimulus at high temporal frequencies was dominated by the surround. In addition, at temporal frequencies above 30 Hz, the center radius increased.
在不同光适应水平下，对猫的X和Y视网膜神经节细胞的时空频率响应进行了测量。使用对比度随时间呈正弦调制的静止正弦亮度光栅或漂移光栅作为刺激。在明视照明下，当空间频率保持在或高于其最佳值时，随着时间频率从1.5 Hz变化到30 Hz，X细胞的响应性基本保持不变。在较低的时间频率下，响应性逐渐下降，而在较高的时间频率下，响应性迅速下降。相比之下，当空间频率保持在较低值时，X细胞的响应性随着时间频率从0.1 Hz时的非常低的值持续增加到高于30 Hz时的显著值，之后响应性再次下降。因此，0周/度成为高于30 Hz时的最佳空间频率。对于明视照明下的Y细胞，时空相互作用更为复杂。当空间频率保持在或高于其最佳值时，响应性保持恒定的时间频率范围比X细胞的短。在较低的空间频率下，这个范围没有明显差异。与X细胞一样，0周/度是高于30 Hz时的最佳空间频率。在明视照明下，均匀场的时间分辨率（定义为响应性降至10个脉冲/秒时的高时间频率）对于X细胞约为95 Hz，对于Y细胞约为120 Hz。在较低的适应水平下，时间分辨率较低。结果根据高斯中心-周边模型进行了解释。对于X细胞，在低和中等时间频率下，周边和中心强度几乎相等，但在高于30 Hz时，周边强度超过中心强度。因此，在高时间频率下对空间均匀刺激的响应由周边主导。此外，在高于30 Hz的时间频率下，中心半径增大。
