MAGNITUDE OF NEGATIVE CONTRAST EFFECT IN RELATION TO DRIVE LEVEL

Two levels of drive were combined factorially with two amounts of reward in a runway experiment involving four groups of 12 rats each. After 18 acquisition trials all groups were shifted to the lower reward for 22 additional trials, with drive maintained at the preshift level A negative contrast effect was obtained only in the goal section at the higher level of drive. A replication of the two reward conditions at the higher level of drive confirmed the finding. The results are consonant with Spence’s emotional-motivational theory of contrast effects. © 1969, Psychonomic Journals, Inc.. All rights reserved.