Stimulus Control

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Stimulus Control
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Stimulus Control

• Reinforcement of an operant response increases
  the likelihood of the future occurrence of the
  response and influences the stimuli that
  immediately precede the response or are present
  during reinforcement.
• The stimuli preceding the response (i.e.,
  antecedent stimuli) may acquire some control over
  the recurrence of that response.
• Behavior that is emitted more often in the
  presence of the SD than during its absence is
  under stimulus control.

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Stimulus Generalization

• When a response is reinforced in the presence of
  one stimulus, there is a general tendency to
  respond in the presence of new stimuli that have
  similar physical properties or have been
  associated with the stimulus.
• This tendency is called stimulus generalization.
• Conversely, discrimination is demonstrated when
  the response is emitted in the presence of new
  stimuli.
• Different degrees of stimulus control are the
  defining characteristics of stimulus
  generalization ad discrimination.
• Stimulus generalization reflects a loose degree
  of stimulus control, whereas discrimination
  indicates a relatively precise degree of control.
• Stimulus generalization is more likely to occur
  when the new stimuli are of similar physical
  dimension but differ from the original stimulus
  only in some quantitative property of that
  dimension.

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Measurement of Stimulus Generalization

• Stimulus generalization gradients are used to
  measure stimulus generalization ad
  discrimination.
• The generalization gradients show the extent to
  which responses reinforced in one stimulus
  condition are emitted in the presence of new
  stimuli.

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Stimulus Discrimination Training

• The basic stimulus discrimination training
  paradigm is usually described as alternating
  conditions of reinforcement and extinction.
• An SD sets the occasion for a response to occur
  that will be reinforced.
• As S? sets the occasion for ay response to
  receive no reinforcement or less frequent
  reinforcement.

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Stimulus and Successive Discrimination

• Discrimination training with differential
  reinforcement can be implemented in one of two
  ways.
• First, two or more different stimuli (SD and S?
  conditions) can be presented at the same time.
• This concurrent presentation of multiple stimuli
  is a procedure of simultaneous discrimination.
• Second, stimulus tasks can be presented in
  sequence, one condition at a time.
• The successive presentation of stimuli is a
  procedure of successive discrimination.

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Response and Stimulus Prompts

• Prompts are supplementary stimuli used to
  increase the likelihood that a student will emit
  a correct response in the presence of the SD,
  which will eventually control the behavior.

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Response Prompts

• Verbal Directions
• Verbal directions can be used as a supplementary
  prompt to occasion a response. Verbal prompts can
  be one word, several words, or even a paragraph
  in length.
• Modeling
• A behavior can be modeled by demonstrating the
  desired behavior so that it can be imitated.
  Modeling prompts are slightly more intrusive than
  verbal prompts because the teacher must
  demonstrate the correct response.

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Response Prompts

• Physical Guidance
• With physical guidance an individual is bodily
  assisted through an action. For example, a
  parent using physical guidance to prompt his
  athetoid cerebral palsied child to eat would
  place his hands on top of the childs, scoop up a
  spoonful of food, and raise the childs hand to
  her mouth. All of the performance is under the
  direction of the parent. Physical guidance is
  the most intrusive of the three response prompts
  mentioned thus far.