Extinction after Training with Runs Being Preceded by Nonrewarded Placements in an Intermittently Rewarding Situation
Two groups of 20 male albino rats were given either 32 rewarded placements (Group E) in a distinctive placement box (PB) or 32 non-rewarded placements (Group C). In the training phase both groups were given two placement trials per day for 20 days. One of these daily placements was non-rewarded (a “frustration treatment” for Group E Ss) and was immediately followed by a rewarded run in a runway. The other placement, not followed by a run, was rewarded for Group E Ss and non-rewarded for Group C Ss. Following a 5-trial transition phase with rewarded runs only, both groups were given 40 extinction runs (without prior placements). The acquisition and transition phase runway performances of the two groups were very similar, but Group E Ss were more resistant to extinction. The extinction findings were predicted from the frustration theory of the partial reinforcement effect.