Related Experiment Video
Updated: Sep 28, 2026

Modeling Verbal Behavior Deficits with the Stimulus Control Ratio Equation, SCoRE
Published on: May 14, 2019
On the nature of the conditioned stimulus: comment on Leri and Stewart (2002)
1Department of Psychology, University of Kentucky, Lexington 40506-0044, USA. mbardo@pop.uky.edu
Abstract:
F. Leri and J. Stewart (2002) present convincing evidence that a relapse to heroin-seeking behavior is established when rats are given a momentary lapse in which they are allowed to respond while under the influence of heroin. Although exposure to a conditioned stimulus (CS) paired with heroin self-infusion did not induce a relapse, it was able to control responding. In addition to serving as both a discriminative stimulus and a conditioned reinforcer, it is argued in this article that the CS also may have positive hedonic value independent of its association with heroin and that this property should be considered in interpreting the results of future experiments.
Related Concept Videos
Real-World Application of Classical Conditioning
Higher-order, or second-order, conditioning occurs when a neutral stimulus becomes associated with an already established conditioned stimulus through repeated pairings. For instance, if a dog has been...
Principles of Classical Conditioning
During the...
Classical Conditioning
Ivan Pavlov observed that dogs salivated...
Associative Learning
Classical conditioning, also known...
Classical Conditioning in Daily Life
John B. Watson and Rosalie Rayner famously demonstrated the development of fear through classical conditioning in their experiment with Little Albert. They paired the...
Behaviorism
The core premise of behaviorism is its focus on observable behavior rather than internal thoughts or feelings. This approach argues that true scientific...

