Abstract
3 groups of fish were trained and extinguished in an alley-type apparatus to assess the effects of partial reinforcement (57% random, 57% single alternation, and 100% continuous). They received 49 training and 49 extinction trials under massed conditions. The results indicated that fish (unlike rats) fail to show a partial reinforcement effect upon resistance to extinction, and they cannot learn to respond appropriately when rewarded and nonrewarded trials are regularly alternated. These results suggested species differences between fish and rats in terms of the rate of conditioning, and the responsivity to changes of aftereffects.
