Chapter 17
What is stimulus control?
•Stimulus control occurs when
–The rate, latency, duration, or amplitude of a response is altered
–In the presence of an
•Stimulus control is acquired when
–Responses are only in the
•Known as the (SD)
–And not in the presence of
•Known as (S
The Development of Stimulus Control
Not to be confused with respondent conditioning
Stimulus Control and Motivating Operations
•Similarities
–Both events occur
–Both events have
•However, they are different
Motivating Operations
•Remember, a motivating operation is something that changes the
of a stimulus as a
–Establishing operation (EO) makes the reinforcer more valuable
–Abolishing operation (AO) makes the reinforcer less valuable
MOs and Stimulus Control
Stimulus Generalization
•Occurs when stimuli that with the evoke the as the controlling stimulus
Stimulus Discrimination
•Occurs when that are do not evoke as the controlling stimulus
Stimulus Control and Stimulus Generalization Are a Continuum
Development of Stimulus Control
•Stimulus discrimination training
–Requires one behavior
–Two antecedent stimulus conditions (the SD and the S)
•Responses that occur are reinforced (thus, the response increases in the presence of the SD)
•Responses that occur are reinforced (thus, the response decreases in the presence of the S
–Can also result in a lesser amount or quality of reinforcement
The Development of Stimulus Control
Concept Formation
•Not a hypothetical construct or mental process
•Complex example of stimulus control that requires
–Stimulus a class of stimuli
–Stimulus classes of stimuli
Example: Concept of Red
•Stimulus generalization across all red objects
–Light red to dark red
–Different objects (car, ball, pencil)
•Stimulus discrimination between red and other colors
–Red ball vs. yellow ball
–Red dress vs. blue dress
Teaching Concepts
•Requires
–Antecedent stimuli representative of a group of stimuli sharing a common relationship ( ) are presented, along with…
–Antecedent stimuli from other stimulus classes ( )
•So that the examples form a stimulus class
Types of Stimulus Classes
•stimulus class
–Stimuli share common (i.e., topographical structures)
–Stimuli share common (i.e., spatial arrangements)
–Developed through
•stimulus class
–Do not share a
–
–Developed using
Stimulus Equivalence
•The emergence of accurate responding to and stimulus-stimulus relations following the reinforcement of responses to
•Useful for teaching complex verbal relations
–Reading
–Language arts
–Mathematics
Testing for Stimulus Equivalence
•Must have a positive demonstration on three different behavioral tests that represent the following mathematical statement:
–If , and
–, then
–
Tests for Stimulus Equivalence
•
–Occurs when in the absence of training and reinforcement, a participant selects a stimulus that is (A = A)
•Matching to sample
•
–Occurs with of the sample stimulus and the comparison stimulus (if A = B, then B = A)
Teach spoken word “bicycle” =
Present and participant matches to
spoken word “bicycle” (as opposed to “car” or “airplane”)
•
–Requires demonstration of
A = B relation (spoken name = picture)
B = C relation (picture = written word)
A = C relation (spoken word = written word)
Matching-to-Sample
•Participant observes the sample stimulus
•The comparison stimuli are then presented
•Participant makes a
–Matches are
–Nonmatches are
•Conditional discrimination training
–Same selection must be correct with , but incorrect with one or more other
Factors Affecting Stimulus Control
•Consistent use of reinforcers contingent upon correct responding in the presence of the SD is critical
•Also important are:
–Pre-attending skills
–Stimulus salience
–Masking and overshadowing
Pre-attending
•A for stimulus control
–Looking at instructional materials
–Looking at teacher when responses are modeled
–Listening to oral instructions
–Sitting quietly for short periods of time
•These may need to be taught before stimulus control procedures are implemented
Stimulus Salience
•of the stimulus in the environment
•Increased saliency facilitates
Masking and Overshadowing
•salience of stimuli
•Competing stimuli of an SD
•To limit the negative effects of these:
–the environment
–Make more intense
–Consistently
Using Prompts
• used to in the presence of an SD (that will eventually control behavior)
–Response prompts operate directly on the
–Stimulus prompts operate directly on the
Response Prompts
•
–Vocal
–Non-vocal (e.g., written)
•
–A demonstration of the desired behavior
•
–Partially physically guide the student’s movements
Stimulus Prompts
•
–Pointing, tapping, touching, looking at
•
–Place one stimulus closer to the student
•
–Stimulus or response dimensions are paired with correct choice
Transfer of Stimulus Control
•Prompts should be used only
•Transfer stimulus control from to quickly using fading
Transferring from Response Prompts
•
–participant through entire performance
–Gradually
•
•
•
•
–Immediately fade physical prompts
–Follow participant closely with hands
–Gradually increase distance between hands and participant
•
–Provide participant with an opportunity to perform the response with the least amount of assistance on each trial
–Participant receives greater degrees of assistance with each successive trial without a correct response
•
–Varying the time interval between presentation of a natural stimulus and the presentation of a response prompt
•
–Begin with a 0-sec delay
–Then use a (e.g., 3 sec)
•
–Begin with a 0-sec delay
–Gradually and (e.g., in 1-sec intervals) according to some rule
Transferring from Stimulus Prompts
•
–Highlighting a and then gradually that exaggerated dimension
–Superimposing one stimulus on top of another and gradually fading it out
•
–Use an initial stimulus shape that will prompt a correct response
–This shape is gradually changed to form the natural stimulus, while maintaining correct responding