EFFECTS OF THE SAMPLE/COMPARISON STIMULUS BAIlO ON CONDITIONAL DISCRIMINATION

Abstract

To evaluate the effects of sample/comparison stimulus ratio on conditional discrimination performance, three pigeons were exposed to a conditional discrimination procedure in which each trial began with the sample stimuli presentation, where the stimulus presentation was either 5 a or 30s. Then two sida keys were illuminated red and green for 3 s. These key colors servad as the comparison stimuli. Qn those trials where a long sample stimulus was presentad the sample/comparison ratio was 10(30/3) and on those trials where a short comparison stimulus was presentad the sample/comparison ratio was 1.67 (5/3). During the 3-s illumination of the comparison key, pecking the red key following a short sample stimulus or pecking the green key following a long sample stimulus was reinforced with access to food. Pecking an incorrect sample key was without consequence. For each subject, the discrimination mdcx was higher, that is, performance was more accurate, when the sample/comparison ratio was 10 than when it was 1.67. The importance of the sample/comparmson ratio a discussed.