TEMPORAL SUMMATION OF MOVING IMAGES BY THE HUMAN VISUAL-SYSTEM
TEMPORAL SUMMATION OF MOVING IMAGES BY THE HUMAN VISUAL-SYSTEM
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DOI：
10.1098/rspb.1981.0010
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发表时间：
1981-01-01
期刊：
影响因子：
--
通讯作者：
BURR, DC
中科院分区：
文献类型：
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作者：
BURR, DC
对小移动点目标、漂移正弦光栅和正弦光栅移动斑块的刺激暴露持续时间进行阈值可见度测量，以研究人类视觉神经系统如何随时间总结运动刺激产生的信号。在图像速度 < 16 度/秒时，移动点的时间求和与静止点的时间求和一样强且延伸（总求和超过约 100 毫秒）。该总和大约是单独考虑空间和时间整合区域所预期的总和的两倍。使用正弦光栅的测量表明，求和的性质主要取决于刺激的空间频率：低空间频率的光栅在运动时（并且仅在运动时）可以很好地求和；高空间频率的那些只有在静止或非常慢的运动时才能很好地求和。使用电子滤波器的模拟模拟表明，这些心理物理结果可以根据人类视觉系统的已知传递特性直接预测（附加阈值概率求和的假设）。对于小块正弦光栅，可以确定穿过视网膜的平移本身对时间总和影响很小。显然，用正弦光栅获得的结果在很大程度上也与小的移动刺激有关，使得用点刺激获得的求和结果可以根据空间选择性视觉探测器的时间传递特性进行讨论。提出对运动中的点观察到的扩展时间求和是由这些刺激中存在的低空间频率的能量求和产生的。
Measurements of threshold visibility were made as a function of duration of stimulus exposure for small moving dot targets, drifting sinusoidal gratings and moving patches of sinusoidal gratings to investigate how the human visual nervous system summates over time signals arising from stimuli in motion. At image speeds of < 16 degree/s, temporal summation is as strong and as extended for moving as for stationary dots (total summation over to about 100 ms). This summation is about twice that which would be expected from separate consideration of the regions of spatial and temporal integration. Measurements with sinusoidal gratings reveal that the nature of the summation critically depends on the spatial frequency of the stimulus: gratings of low spatial frequency summate well when in motion (and only when in motion); those of high spatial frequency summate well only when stationary or in very slow motion. An analog simulation with electronic filters showed that these psychophysical results are directly predictable from the known transfer characteristics of the human visual system (with the additional assumption of probability summation at threshold). With small patches of sinusoidal grating, it was established that translation per se across the retina has little effect on temporal summation. Apparently, the results obtained with sinusoidal gratings of a large extent are also relevant to small moving stimuli, allowing the summation results obtained with dot stimuli to be discussed in terms of the temporal transfer properties of spatially selective visual detectors. It is proposed that the extended temporal summation observed for dots in motion results from summation of energy of low spatial frequency present in these stimuli.