Positive contrast in the runway obtained with delay of reward.
The failure to find positive contrast effects in the runway may be attributed to a ceiling effect that can be overcome with the use of delay of reward. Rats were trained one trial a day in a runway with small, medium, or large reward. When a shift to large reward was combined with delay of reward, shift groups slowed down less than controls.
D000704:Analysis of Variance; D000818:Animals; D008297:Male; D009043:Motor Activity; D051381:Rats; D012201:Reward; D013997:Time Factors