Response decrements produced by extinction and by response-independent reinforcement.

The effects of extinction and of response-independent (free) reinforcement in decreasing rates of key pecking by pigeons were compared in single schedule (Phase 1) and multiple (Phase 2) conditions. In both phases, response rates decreased more rapidly with extinction than with free reinforcement conditions. Behavioral contrast was obtained from subjects trained in a multiple schedule involving extinction in Phase 2, whereas subjects trained in a multiple schedule involving free reinforcement showed a slight negative induction effect. Whether subjects experienced extinction or free reinforcement under single stimulus conditions did not affect subsequent performance in the discrimination situation of the second phase. Disinhibition testing was carried out at the end of both phases, but there was no evidence for disinhibitory effects under any condition.