OLFACTORY INTENSITY-DIFFERENCE THRESHOLDS IN PIGEON

Used methods of single stimuli and constant stimuli with a modified conditioned suppression technique to determine olfactory intensity-difference thresholds in 3 White Carneaux and 3 White King pigeons. While responding for grain reinforcement on a variable interval 2-min schedule, conditioned suppression was established in the Ss after several sessions by pairing amyl acetate odor at 7% of vapor saturation with electric shock. The degree of suppression to nonshocked lower intensities of this odor determined the discrimination learning (DLs). Weber fractions computed from these values ranged .6-.7. Both psychophysical methods produced identical DLs. Olfactory nerve section abolished the 7% intensity response in all Ss, showing that odor was the only cue utilized by the birds during preoperative discriminations. (21 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.