PERCEPTUAL-LEARNING IN PIGEONS - DECREASED ABILITY TO DISCRIMINATE SAMPLES MAPPED ONTO THE SAME COMPARISON IN MANY-TO-ONE MATCHING

Humans often treat two stimuli that are associated with a common respo nse as similar in other contexts, They do so presumably because those stimuli become conceptually or perceptually more similar to each other (perceptual learning), An analogous phenomenon may occur in pigeons w hen they are trained with a matching-to-sample procedure in which more than one sample is mapped onto the same comparison, In the present re search, pigeons were trained to select one comparison following either of two samples (S-1 or S-2) and to select the other comparison follow ing either of two different samples (S-3 or S-4). When the samples wer e then presented as positive and negative stimuli in a simple successi ve discrimination, samples that had been associated with the same comp arison during original training (e.g., S-1 vs. S-2) were more difficul t to discriminate than were samples that had been associated with diff erent comparisons (e.g., S-1 vs. S-3). Thus, it appears that perceptua l learning occurs in pigeons as well.