[The dynamic changes in the confidence of recognition in the learning of a highly structured set of stimuli]

In this study using a highly structured set of stimuli, each stimulus had five attributes and each attribute could take one of two values. Two stimuli were selected from the set for the control condition and three for the experimental condition. Two learned stimuli in the control condition were those which could be transformed between one another by four relevant transformations. Among the not-learned stimuli a few stimuli were related to the learned stimuli by relevant transformations and were called generative stimuli, while the leftover stimuli were called ungenerative stimuli. In the experiment, the subjects memorized two or three learned stimuli and immediately recalled them. After several minutes of an inserted task, they made "old" or "new" judgments of the test stimuli and then rated their own confidence of judgment. The experimental results showed that; (a) the recognition confidence was highest for the learned stimuli, the second highest for the generative stimuli, and lowest for the ungenerative stimuli, and (b) the learning of the third stimulus increases the confidence of the generative stimuli. The main conclusion is that the recognition confidence for the test stimuli systematically change, as stimuli in a highly structured set of stimuli are learned one after the other.