Effects of Preshift Small Magnitude of Reward Received during Goalbox Placements on the Negative Contrast Effect

Abstract

During preshift, one experimental group of rats was given a large magnitude of food reward following a traversal of a straight alley and during a goalbox placement, while the other experimental group was given a small reward during goalbox placement and a large reward following a run. During postshift, all experimental groups were given a small reward of food following a traversal down the runway and during a goalbox placement. A control group was maintained on small reward during placements and following a traversal throughout the study. Only the group who received preshift large reward during placement and following a runway response ran slower to small reward during postshift than the control group maintained on small reward (negative contrast effect).

Perseveration of the Partial Reinforcement Effect in Extinction with Rats over Two Phases of Extinction and Two Stages of Continuous Reinforcement

“…A straight runway was used in the present study similar to that of Calef, Choban, Glenney, Calef, Mace, and Cummings (2004). The running and goal sectors were painted black, and photocells and clock circuits were used to obtain a traversal time over the first and last 30.5 cm (1 ft.) segments of the run and goal measures.…”