Experimental design of the two category learning phases for the different groups: In the Blocked and Intermixed Discrimination tasks, stimuli were categorized with regard to one of two category labels on each trial.

In the Triplet Discrimination task, stimuli were to be assigned to one of either two or three category labels on each trial. In the Identification task, only one category label was presented (the category in parenthesis was not shown), and participants had to decide whether the stimulus belonged to that category or not. The transfer phase was the same for all groups. Stimuli had to be assigned to one of two category labels (B and C) which were never explicitly discriminated before (but all groups separately classified instances of both B and C).