A stimulus in the presence of which responses have been reinforced and in the absence of which the same responses have occurred and not been reinforced is called what?

• A. Discriminated avoidance
• B. Exclusion time out
• C. Discriminative stimulus
• D. Discriminated operant

Answer: (C)

Discriminative stimulus signals that reinforcement for a specific response is available in its presence and not available in its absence. The organism has learned that when this stimulus is present, performing the response will be reinforced, and when it’s absent, the same response is not reinforced. That exactly matches the description in the question.

The other terms refer to different ideas: an exclusion timeout is a punishment procedure removing the individual from the environment; discriminated avoidance involves taking a action to avoid an aversive event after a warning cue; and a discriminated operant describes the operant behavior under the control of a discriminative stimulus, not the stimulus itself.