Reeves A
Perception. 1982;11(4):415-26. doi: 10.1068/p110415.
Different underlying processes account for the descending and ascending portions of the metacontrast U-shaped function obtained in the flanking-masks paradigm. One or another process is dominant on each trial. Each process is monotonic with stimulus onset asynchrony in the region in which it can be measured. The two processes may be isolated by asking the subject to report on each trial not only target visibility but also whether target and mask appear simultaneous or not. Standard U-shaped functions could be obtained only as an artifact of averaging across these different types of trials.
在侧翼掩蔽范式中获得的元对比U形函数的下降和上升部分由不同的潜在过程所导致。在每个试验中，一种或另一种过程占主导。每个过程在其可测量的区域内随刺激起始异步性呈单调变化。通过要求受试者在每次试验中不仅报告目标可见性，还要报告目标和掩蔽是否同时出现，可以分离这两个过程。标准的U形函数只能作为对这些不同类型试验进行平均的人为结果而获得。
