Yo C, Wilson H R
Department of Ophthalmology and Visual Science, University of Chicago, IL 60637.
Vision Res. 1993 Jan;33(1):33-45. doi: 10.1016/0042-6989(93)90056-3.
Perceived temporal frequency is vastly underestimated in the peripheral visual field, as all temporal frequencies above 10 Hz are perceived as flickering at 10 Hz even after scaling for acuity. Varying the contrast and spatial frequency of the peripheral pattern four-fold have negligible effects on the perceived flicker rate. Speed and auditory matching experiments also support this finding. Despite the saturation of perceived temporal frequency, frequency discrimination beyond 10 Hz was as accurate as in the fovea. By using a temporal masking paradigm, we obtained threshold elevation data that could be accounted for by three overlapping, broadly tuned temporal channels peaking at 5.5, 12 and 22 Hz. Based on these temporal frequency channels, we proposed that the visual system uses a line-element scheme for mediating temporal frequency discrimination, but adopts a weighted-average method for determining perceived temporal frequency. In the peripheral visual field, the weight assigned to the highest temporal channel is much larger than those assigned to the lower frequency channels.
在周边视野中，感知到的时间频率被大大低估，因为即使在根据视敏度进行缩放后，所有高于10Hz的时间频率都被感知为以10Hz闪烁。将周边图案的对比度和空间频率变化四倍，对感知到的闪烁频率影响可忽略不计。速度和听觉匹配实验也支持这一发现。尽管感知到的时间频率已饱和，但超过10Hz的频率辨别与中央凹一样准确。通过使用时间掩蔽范式，我们获得了阈值升高数据，这些数据可以由三个重叠的、调谐宽泛的时间通道来解释，它们分别在5.5Hz、12Hz和22Hz达到峰值。基于这些时间频率通道，我们提出视觉系统使用线元方案来介导时间频率辨别，但采用加权平均方法来确定感知到的时间频率。在周边视野中，分配给最高时间通道的权重远大于分配给较低频率通道的权重。
