Doing the Right Thing at the Right Time and Place: Stimulus

Discrimination and Generalization

Chapter 8

Stimulus Discrimination Learning and Stimulus

Control• How do we learn to perform certain

behaviors at certain times but not others?

• Always cues around when behavior is reinforced or extinguished

• Situations in which behaviors occur analyzed in terms of:– Antecedent Stimuli – stimuli that exist just

prior to behavior– Behavior– Consequences

Stimulus Discrimination Learning and Stimulus

Control Stimulus Control Degree of correlation between a stimulus and

subsequent response Good or Effective stimulus control

High correlation Stimulus Discrimination

Process by which we learn to emit a specific behavior in the presence of some stimuli and not in the presence of other stimuli

Stimulus Discrimination Training Process of teaching stimulus discrimination

Controlling Stimuli Reinforcement in the presence of specific stimuli or

extinction in the presence of different stimuli

Types of Controlling Stimuli

• SD – Discriminative Stimulus for Reinforcement– Response has been reinforced only in the

presence of a particular stimulus– Cue that a particular response will pay off

• S - Discriminative Stimulus for Extinction– Response has been extinguished only in the

presence of a particular stimulus– Cue that a particular response will not pay

off• A stimulus may be simultaneously an SD

for one response and an S for another

Stimulus Generalization

• Responding the same way to two different stimuli

• Opposite of stimulus discrimination• Unlearned Stimulus Generalization

due to Considerable Physical Similarity– Likely to perform a behavior in a new

situation if that situation is similar to situation when behavior was learned

Stimulus Generalization

• Learned Stimulus Generalization Involving Minimal Physical Similarity– Have to learn the stimulus class, or

concept– Stimulus common-element class

• Set of stimuli, all of which have some physical characteristic in common

• Conceptual behavior – emitting appropriate behavior to all members of a stimulus common-element class, but not those that don’t belong

Stimulus Generalization

• Learned Stimulus Generalization due to Stimulus Equivalence Class– Stimulus Equivalence Class

• set of completely dissimilar stimuli in which all members of the class control the same response

Effectiveness of Stimulus Discrimination Training

• Choose distinct signals• Minimize opportunities for error• Maximize the number of trials

– Need multiple trials to learn the behavior

• Make use of rules: describe the contingencies– Rules can speed up learning

Pitfalls

• Can be misapplied• May inadvertently teach others to

respond inappropriately to particular cues

Guidelines for Effective Stimulus Discrimination

Training• Choose distinct goals• Select an appropriate reinforcer• Develop the discrimination

– Arrange for several reinforced responses in the presence of the SD

– When the S is presented, make the change from the SD very obvious and follow the rules for extinction for the behavior of concern

• Wean the individual from the program – Plan natural reinforcers– Plan periodic assessments of behavior to make

sure it is occasionally being reinforced and that the desired frequency of the behavior is being maintained in the presence of the SD