Abstract: | Experiment 1 (n = 110 male rats) showed that pairing sucrose with toxicosis under forward or backward conditioning procedures yielded reliable poison-enhanced neophobia toward casein hydrolysate. Forward procedures produced reliably greater and more persistent enhancement of neophobia. Experiment 2 (n = 160 male rats) showed that interpolating 10 min, or 1, 4, 8, or 12 hr between sucrose and toxicosis yielded reliable aversion effects to sucrose and poison-enhanced neophobia to casein at each interval except 8 and 12 hr. Generally speaking, the effects of training interval were similar for conditioned aversion and enhanced neophobia but conditioned aversion effects were more enduring. |