Stimulus Discrimination Training

Stimulus discrimination training is a strategy that is used to teach an individual to engage in particular behaviors in the presence of certain situations, events, or stimuli. Specifically, this is a procedure in which a response is trained to occur in the presence of a particular stimulus and to not occur in the presence of other stimuli. When a response is trained to occur in a particular situation, this situation or stimulus is referred to as a discriminative stimulus, or SD. When a response is trained to not occur in a given situation, this situation or stimulus is referred to as Sρ, or S-delta. Hence, during training, the behavior is reinforced when it occurs in the presence of a discriminative stimulus and is not reinforced when the discriminative stimulus is not present. It is important to note that a discriminative stimulus signals the availability of the reinforcer for the designated behavior, but it does not cause the behavior to occur. Rather, the behavior is more likely to occur because it has been reinforced in the past in the presence of the discriminative stimulus.

It is helpful to use an everyday experience to understand stimulus discrimination training. When a person approaches a traffic light, he or she responds differently depending on the color of the light. In the presence of a red light, the person pushes the brake pedal because this behavior has been reinforced in the past. However, in the presence of other color lights, pushing the brake pedal does not occur. Pushing the brake pedal in the presence of a red light is reinforced (e.g., safely arriving at the destination), but pushing the brake pedal in the presence of other stimuli (e.g., a green light) is not reinforced (and likely is punished by others honking or yelling at the driver).

Many examples of child behavior are impacted by stimulus discrimination training. Often, parents report that children act differently depending on the adults present or on the setting (e.g., the child is more compliant with one parent than the other or behaves more appropriately in one class than in another). These differences likely are due to stimulus discrimination training. That is, the child has learned that some behaviors [Page 1061]are more likely to elicit reinforcement in certain situations or in the presence of certain adults, whose presence may be conceptualized as discriminative stimuli.

Stimulus discrimination training also is involved in traditional academic education. For example, if a child responds “4” in the presence of the question “What is 2 + 2,” the behavior of saying “4” will be reinforced, but saying “4” will not be reinforced in the presence of the question “What is 2 + 5?” Accordingly, the child is trained to discriminate between those stimuli that do and do not signal the availability of reinforcement for the response “4.” This same explanation can be applied to learning in many other capacities.