SAWTOOTH CONTRAST SENSITIVITY - DECREMENTS HAVE THE EDGE
SAWTOOTH CONTRAST SENSITIVITY - DECREMENTS HAVE THE EDGE
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DOI：
10.1016/0042-6989(89)90134-x
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发表时间：
1989-01-01
期刊：
影响因子：
1.8
通讯作者：
SMITH, VC
中科院分区：
文献类型：
--
作者：
BOWEN, RW;POKORNY, J;SMITH, VC
镜像锯齿波形（快速启动和快速关闭）用于测试对增量和减量刺激的敏感性差异。测量快速开启和快速关闭锯齿波以及正弦波刺激（2-26 Hz，平均视网膜照度为 500 td，圆形目标为 1.8 度，中心凹）的时间对比敏感度函数。在低频和中频下，快速关闭锯齿波比快速开启锯齿波产生更高的灵敏度。检测递减光的这一优点在一项实验中得到了证实，在该实验中，对比灵敏度是针对在整个相位角范围内添加的快速开启和快速关闭波形的总和来确定的。我们的数据基于周期性刺激而不是脉冲刺激，扩大并强化了视觉系统对光强度的减弱比对光强度的增加更敏感的证据。
Mirror-image sawtooth waveforms (rapid-on and rapid-off) were used to test for differences in sensitivity to incremental and decremental stimuli. Temporal contrast sensitivity functions were measured for rapid-on and rapid-off sawtooths and for sine wave stimuli (for 2-26 Hz, mean retinal illuminance of 500 td, circular target of 1.8 deg, foveal). Rapid-off sawtooths yielded higher sensitivity than rapid-on sawtooths at low and middle frequencies. This advantage for detection of decremental lights was confirmed in an experiment in which contrast sensitivity was determined for the sum of a rapid-on and a rapid-off waveform added over the full range of phase angles. Our data, based on periodic rather than pulsed stimuli, broaden and strengthen the evidence that the visual system is more sensitive to decrements than to increments in light level.