1.5 Definition of Discriminative Stimulus
The next term is discriminative stimulus, which is a stimulus in the presence of which a given response has a history of being reinforced. For example, if a hungry lab rat receives a pellet (reinforcement) for pressing a bar only when a red light is on, the red light is probably functioning as a discriminative stimulus.
| Term | Definition |
|---|---|
| Stimulus | A physical energy change capable of affecting an organism through one of its receptors: photoreceptors, phonoreceptors, chemoreceptors (gustatory and olfactory), mechanoreceptors (touch), thermoreceptors, and free nerve endings. |
| Discriminative Stimulus | A stimulus in the presence of which a given response has a history of being reinforced. |
Discriminative stimulus (SD) is conditioned through learning history.
Discriminative stimulus always have history associated
This example makes sense because the red light is basically a cue that tells the rat, “pressing the bar will work right now.” I like how it shows that an SD is only meaningful because of the reinforcement history connected to it.
The discriminative stimulus is something that has been conditioned through previous reinforcement.
I think of the discriminative stimulus as an introduction/ heads up that reinforcement is going to occur.
Discriminative stimulus signals when a behavior is likely to receive reinforcement.