Figure 5.

Prototype learning (27). Examples of the 40 study items and 84 test items used to study prototype learning. The study items are all distortions of a prototype (average) dot pattern that is never presented. For training, the 40 study patterns are presented for 5 sec each, and the subject points to the dot closest to the center of the pattern (to guarantee attention). Five minutes later, subjects are instructed that the dot patterns they have just seen all belong to a single category of patterns in the same sense that, if a series of different dogs had been presented, they would all belong to the category “dog.” Then for each of 84 new dot patterns subjects judge (yes/no) whether or not it belongs to the same category as the training patterns. The test items consist of four repetitions of the prototype, 20 new “low” distortions of the prototype, 20 new “high” distortions of the prototype, and 40 random dot patterns.