Visual and Olfactory Oddity Learning in Rats: What Evidence is Necessary to Show Conceptual Behavior?

Investigated the oddity concept in 2 experiments with 7 rats. Exp I involved the use of plastic and wooden objects and trial-unique problems. The Ss performed successfully on nonconceptual oddity problems given before and after conceptual training, showing that the testing conditions were suitable, but they showed chance performances on the trial-unique problems. Ss involved the use of olfactory discriminanda. Five pretraining problems and 300 unique 5-trial problems were presented. Two of 3 Ss performed better than chance on Trial 2 and Trials 3–5, but all performed at chance levels on Trial 1 throughout. Data suggest that the Ss responded to specific odors on Trials 2–5 following the Trial 1 experience, as opposed to responding conceptually to the odd odor. Had they responded conceptually to odd odors, they should have performed better than chance on Trial 1