SD (discrimitive stimulus)
• discriminative stimulus (Sd or SD) is created when the response is reinforced in its presence, but not when it is absent
1. An antecedent stimulus
2. In the presence of which the consequential operation is in effect
3. In the absence of which the behaviour can occur but the consequential operation is not in effect
• Example: a child requests to watch TV and historically, he is granted more screen time when his Mom has to get on a conference call for work, but never when she doesn’t have to take a call
S-delta (extinction stimulus)
• imagine thatyou taught your dog to shake hands. Over time, the trick became less interesting. You stop rewarding the behavior and eventually stop asking your dog to shake. Eventually, the response becomes extinct, and your dog no longer displays the behavior.
1. An antecedent stimulus 2. In the presence of which the behaviour can occur but the consequential operation is not in effect 3. In the absence of which the consequential operation is in effect
Operant stimulus discrimination training
refers to the procedure of reinforcing a response in the presence of an SD and extinguishing that response in the presence of an SΔ. After sufficient stimulus discrimination training, the effects can be described as (1) good stimulus control—a strong correlation between the occurrence of a particular stimulus and a particular response, or (2) a stimulus discrimination—a response occurs to an SD, not to an SΔ.
Operant stimulus generalization
• refers to the procedure of reinforcing a response in the presence of a stimulus or situation and the effect of the response becoming more probable not only in the presence of that stimulus or situation, but also in the presence of another stimulus or situation. In other words, instead of discriminating between two stimuli and responding differentially to them, an individual responds in the same way to two different stimuli. Thus, stimulus
generalization is the opposite of stimulus discrimination
Common element stimulus class
- a set of stimuli, all of which have one or more physical characteristics in common. For example, cars typically have four wheels, windows, and a steering wheel.
- Example: When a child learns to say the word car when seeing a particular car, the child is likely to show unlearned stimulus generalization and be able to identify other cars.
Stimulus equivalence class
- a set of completely dissimilar stimuli—i.e., have no common stimulus element— which an individual has learned to group or match together or respond to in the same way.
- Example: if a child has learned to becryin the presence of dogs, this may transfer to crying when seeing a cat as well because they are both fluffy animals in the same stimulus class
Factors influencing the effectiveness of stimulus discrimination
- Choosing Distinct Signals
- greater the similarity, more difficult the discrimination - Minimize the opportunity for error
- add prompts - Maximize # of trials
- both SD and S-delta presentations
- correction procedure - Instructions
- specify ABC
- specify antecedents and consequences for both correct + incorrect responses - Overt responding
- improves discrimination training - Use intermittent reinforcement (tentative)
- small ratio schedules (vs. CRF) for correct responding may improve attention - Order of stimulus presentation
- cumulative vs. all-at once
- all-at-once would entail teaching all 3 discriminations from start
- cumulative would entail teaching 1 discrimination and only adding a new one to the mix after current discrimination is mastered - Stimulus specific reinforcement
- dfferential outcomes effect
- use when teaching multiple discriminations
Reflexivity, Symmetry and Transivity
Reflexivity simply involves recognizing instances of a
stimulus. In other words, a child is able to match 3 to 3, ∴ to ∴, and III to III
Symmetry involves being able to recognize the equality of two different stimuli, so that if A = B then B = A.
Transitivity is demonstrated when the
child passes the test in the third panel shown in Figure 11.1. In other words, as a result of learning to match A to B and B to C, an individual now matches C to A without specific training to do so.
