Figure 5.

Experimental results (A) and simulated results (B) of a study on the feature-positive effect in object category learning by pigeons (Edwards and Honig, 1987). In the feature-positive discrimination, objects from a category predict the delivery of reward, whereas in the feature-negative discrimination, objects from a category predict absence of reward. In the pseudocategorization task, different objects from the same category predict either reward or no reward.