Ratcliff Roger
Department of Psychology, The Ohio State University, Columbus, OH 43210, USA.
Cogn Psychol. 2006 Nov;53(3):195-237. doi: 10.1016/j.cogpsych.2005.10.002. Epub 2006 Aug 4.
The diffusion model (Ratcliff, 1978) and the leaky competing accumulator model (LCA, Usher & McClelland, 2001) were tested against two-choice data collected from the same subjects with the standard response time procedure and the response signal procedure. In the response signal procedure, a stimulus is presented and then, at one of a number of experimenter-determined times, a signal to respond is presented. The models were fit to the data from the two procedures simultaneously under the assumption that responses in the response signal procedure were based on a mixture of decision processes that had already terminated at response boundaries before the signal and decision processes that had not yet terminated. In the latter case, decisions were based on partial information in one variant of each model or on guessing in a second variant. Both variants of the diffusion model fit the data well and both fit better than either variant of the LCA model, although the differences in numerical goodness-of-fit measures were not large enough to allow decisive selection between the models.
扩散模型（拉特克利夫，1978年）和泄漏竞争累加器模型（LCA，厄舍和麦克莱兰，2001年）通过标准反应时程序和反应信号程序，针对从同一受试者收集的二选一数据进行了测试。在反应信号程序中，先呈现一个刺激，然后在实验者确定的多个时间点之一，呈现一个做出反应的信号。在假设反应信号程序中的反应基于信号出现前已在反应边界终止的决策过程和尚未终止的决策过程的混合的前提下，将这些模型同时拟合到来自这两种程序的数据上。在后一种情况下，决策在每个模型的一个变体中基于部分信息，或者在第二个变体中基于猜测。扩散模型的两个变体都能很好地拟合数据，并且都比LCA模型的任何一个变体拟合得更好，尽管数值拟合优度指标的差异不够大，无法在这些模型之间做出决定性的选择。
