Department of Psychology, University of Reading, Building 3, Earley Gate, Whiteknights, RG6 2AL, Reading, England.
Mem Cognit. 1976 Sep;4(5):525-31. doi: 10.3758/BF03213214.
Observers made same-different shape judgments of stimuli that were identical in shape and size different in shape but not in size, or differed in relative size along a number of steps for both same- and different- shaped forms. "Same" judgment RTs increased monotonically with increases in the magnitude of the relative size difference. In contrast, "different" judgment RTs were unaffected by changes in relative size. A second experiment in which stimulus presentation was successive rather than simultaneous yielded essentially the same results. Consideration was given to a dual- process model in which a time-consuming analog process normalizes stimuli that are size discrepant prior to a comparison stage that is operative for those structures responsible for "same" decisions but not for "different" judgments. Some evidence that seems inconsistent with a normalization process which operates prior to contact with memory was discussed, and an alternative explanation in which the early detection of a size difference causes changes in decision criteria was suggested.
观察者对形状和大小相同但形状不同或相对大小在多个步骤上不同的刺激进行相同-不同形状判断。“相同”判断的 RT 随着相对大小差异的增大而单调增加。相比之下，“不同”判断的 RT 不受相对大小变化的影响。在一个刺激呈现是连续而不是同时的第二个实验中，得到了基本相同的结果。考虑了一种双过程模型，其中耗时的模拟过程在比较阶段之前对大小不一致的刺激进行归一化，比较阶段适用于负责“相同”决策的结构，但不适用于“不同”判断。讨论了一些似乎与在接触记忆之前进行归一化过程不一致的证据，并提出了一种替代解释，即大小差异的早期检测导致决策标准的变化。
