Extinction
Extinction n Operant Extinction: n No longer reinforcing operant behavioral response n Ultimately reducing B s probability to zero n Ideally combined with DRO (esp. DRI)
n Initial & Temporary Effects n Extinction Burst Effects of Extinction n Emotional Behaviors n Frustration n emotion when no longer reinforced n Aggression n (kicking, cursing; biting: my cat!)
Effects of Extinction cont. n Other Effects (most occur soon, disappear quickly) n Increase in Behavior Variability n Resurgence n Depression n Spontaneous Recovery n recovery of extinguished response after a sufficient break n Ultimately, response decreases (or is eliminated entirely)
Resistance to Extinction (RTE) n Ext. takes longer under intermittent reinforcement n PRE (Partial Reinforcement Effect) n Resistance to Extinction: extinction takes longer n CRF schedules have low RTE (extinguish rapidly) n Intermittent schedules have high RTE (ext. slowly) n To decrease RTE (best strategy): Combine extinction of inappropriate B with reinforcement of incompatible B (DRI)
Generalization & Discrimination n Discriminative Stimuli n Stimulus Control n Stimulus Generalization n Generalization Gradient n Stimulus Discrimination n Discrimination Training n Peak Shift
Stimulus Discrimination n Stimulus Discrimination: The tendency for an operant response R to be emitted more in the presence of one stimulus than another.
Discriminative Stimuli n Pigeon learns to emit key peck R to obtain S R of food: R (peck) à S R (food) n Reinforce R only in the presence of a lighted key: S D (yellow key): R (peck) à S R (food) n Discriminative Stimulus (S D ): a stimulus in the presence of which responses are reinforced and in the absence of which they are NOT reinforced.
Stimulus Control n Stimulus Control: When the presence of a discriminative stimulus S D reliably affects the probability of the behavior R. n Examples: n Pigeon more likely to peck key when it s lit up. n Drivers more likely to pull into gas station when low fuel light comes on.
Stimulus Generalization n Stimulus Generalization: The tendency for an operant response R to be emitted in the presence of a stimulus that is similar to the Discriminative Stimulus S D. n S D (Yellow Key): R (Peck) à S R (Food) n What happens if we expose the Pigeon to key lights of different colors?
Generalization Gradient
Discrimination Training n Not always desirable for a B to occur in every situation (e.g. flirting during a funeral) n How do we behave appropriately in each situation? n Discrimination Training involves reinforcement of responding in the presence of one stimulus (the S D ) and not another stimulus. n Discriminative Stimulus for Extinction S Δ : A stimulus that signals the absence of reinforcement.
Discrimination Training Examples n Pigeon: S D (Yellow Key): R (Peck) à S R (Food) AND S Δ (Blue Key): R (Peck) à NO Food n Human: S D (Friends): R (casual) à S R (Social Approval) AND S Δ (Interviewer): R (casual) à NO Social Approval n Human: S D (Smile): R (pickup line) à S R (Flirt) AND S Δ (Glare): R (pickup line) à Rejection
2 Types of Discrimination Training n Intradimensional: Both S D & S Δ are from the same dimension (e.g., same spectrum, noise type, etc.) n Interdimensional: S D & S Δ are from different dimensions (e.g., S D = light; S Δ = sound) n Having a stimulus being ON vs. OFF also counts (e.g., S D = light ON; S Δ = light OFF) n Intra = within (Intramural sports) n Inter = between (Interstate highways)
Peak shift
The Peak Shift n Peak shift has two crucial elements: n Peak is no longer centered over S D n The entire gradient has shifted away from S Δ n What causes the Peak Shift? n Interaction bet. Excitatory and Inhibitory Gradients n Excitatory gradient (S D ) n Inhibitory gradient (S Δ ) usually more flat n Peak shift occurs ONLY after Intradimensional training