Ratcliff R, Rouder J N
Department of Psychology, Northwestern University, Evanston, Illinois 60208, USA.
J Exp Psychol Hum Percept Perform. 2000 Feb;26(1):127-40. doi: 10.1037//0096-1523.26.1.127.
The diffusion model developed by R. Ratcliff (1978, 1981, 1985, 1988) for 2-choice decisions was applied to data from 2 letter identification experiments. In the experiments, stimulus letters were displayed and then masked, and the stimulus onset asynchrony between letter and mask was manipulated to vary accuracy from near chance to near ceiling. A standard reaction time procedure was used in one experiment and a deadline procedure in the other. Two hypotheses about the effect of masking on the information provided to the decision process were contrasted: (a) The output of perception to the decision process varies with time, so that the information used by the decision process rises and falls, reflecting the stimulus onset and mask onset. (b) The output of perception to the decision is constant over time, reflecting information integrated over the time between the stimulus and mask onsets. The data were well fit by the diffusion model only with the assumption of constant information over time.
R. 拉特克利夫（1978年、1981年、1985年、1988年）开发的用于二选一决策的扩散模型被应用于两项字母识别实验的数据。在实验中，呈现刺激字母然后进行掩蔽，字母与掩蔽之间的刺激开始异步性被操控，以使准确率从接近随机水平变化到接近上限水平。在一项实验中使用了标准反应时程序，在另一项实验中使用了截止期限程序。关于掩蔽对提供给决策过程的信息的影响的两个假设进行了对比：（a）感知到决策过程的输出随时间变化，因此决策过程使用的信息上升和下降，反映刺激开始和掩蔽开始。（b）感知到决策的输出随时间恒定，反映在刺激和掩蔽开始之间的时间内整合的信息。只有在假设信息随时间恒定的情况下，数据才能很好地拟合扩散模型。
