Classical, or Pavlovian, conditioning is a process by which new emotional and glandular reactions develop in response to previously neutral stimuli in the environment. But classical conditioning doesn't explain how we develop new skills or behaviors instrumental in changing our external environments. That learning process involves what is typically referred to as instrumental, or operant, condi...

The earliest studies of operant learning can be traced back to the research of psychologist E. L. Thorndike with cats in puzzle boxes (Kimble, 1961). In Thorndike's experiments, hungry cats had to escape from boxes fastened shut in different ways to obtain food. Thorndike observed that after being placed in the boxes, the cats engaged in various behaviors such as pacing, visually exploring, and...

Animals can learn to repeat a response when reinforcement is contingent upon accurate repetitions or to vary when reinforcement is contingent upon variability. In the first case, individual responses can readily be predicted; in the latter, prediction may be difficult or impossible. Particular levels of variability or (un)predictability can be reinforced, including responses that approximate a ...

Operant methods are powerful behavioral tools for the study of motivated behavior. These 'self-administration' methods have been used extensively in drug addiction research due to their high construct validity. Operant studies provide researchers a tool for preclinical investigation of several aspects of the addiction process. For example, mechanisms of acute reinforcement (both drug and non-dr...