For over a century and a quarter, the science of learning has expanded at an increasing rate and has achieved the status of a mature science. It has developed powerful methodologies and applications. The rise of this science has been so swift that other learning texts often overlook the fact that, like other mature sciences, the science of…

Several recent studies have explored what Michael (e.g., 1982) termed the "value-altering" effect and the "behavior-altering" effect of motivating operations. One aspect of the behavior-altering effect that has garnered no recent attention involves changes in stimulus control produced by motivating operations. To call attention to this aspect of…

Extinction and recovery of the discriminative stimulus effects of nicotine (0.3 mg/kg) was investigated with a devalued food reinforcer (rats sated). Sixteen rats were trained in a counterbalanced one manipulandum (nose-poke) drug discrimination procedure with the roles of nicotine and saline counterbalanced as S[superscript D] and S[superscript…