Negative induction and local negative contrast as a function of an added stimulus in one component of a multiple fixed interval schedule

Abstract

Two experitnentally naive femaie pigeons were trained to peck response keys on a two-component multiple fixed-interval one-minute schedule. When the changed compo­nent of the mu!tiple schedule was manipulated such. that the discriminative stirnulus blinked interinittently during the 31 to 42-second portion of the fixed interval, overall negative induction effects were observed. The most dramatic response rate decreases in the unchanged conrpanent occurred in the corresponding segment to that where the dis­criminative stimu!us had been blinked in the changed component. Slight negative contrast effects were noted in tire first thirty second partían of tire respective fixed intervals. The response rates recovered when conditions were returned to tirase associated witir baseline.