Abstract
Goldfish were trained and extinguished in an alley-type apparatus in order to test the assumption that the PRE could be found even in fish by strengthening the rate of conditioning to the stimulus aftereffect of nonreinforcement. There were 3 groups: 2 partial reinforcement groups in which reinforcement ratios were gradually increased (Group gI) or decreased (Group gD), and one continuous reinforcement (control) group. The PRE was not found in Group gI. Group gD showed the least resistance to extinction, These results suggest that resistance to extinction is influenced mainly by a series of reinforced trials very close to the extinction period, but not influenced by the aftereffect of nonreinforcement.
