Extinction of Conditioned Behavior Effects of Extinction the rate of responding decreases response variability increases experiment by Neuringer,
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Extinction of Conditioned Behavior
Effects of Extinction the rate of responding decreases response variability increases experiment by Neuringer, Kornell, & Olufs (2001)
Extinction does not eliminate the original learning
Spontaneous Recovery Renewal Reinstatement US-devaluation
What is learned during extinction?
The non-reinforcement of a response in the presence of a specific stimulus produces an inhibitory S-R association that suppresses that response whenever S is present
Partial Reinforcement Extinction Effect
Extinction is slower if a partial reinforcement schedule, rather than CRF, was in effect before extinction
Possible explanations: Discrimination hypothesis Frustration hypothesis Sequential memory hypothesis
Stimulus Control of Behavior
Stimulus control Stimulus discrimination Generalization Gradient
Stimulus and Response Factors in Stimulus Control
sensory capacity relative ease of conditioning various stimuli
• overshadowing type of reinforcement
• certain types of stimuli are more likely to gain control over the instrumental response with positivereinforcement than with negative reinforcement
type of instrumental response
• experiment by Foree & LoLordo (1973)
• experiment by Dobrzecka, Szwejkowska, &Konorski (1966)
Foree & LoLordo (1973)2 groups of pigeons trained to press a foot treadle in the presence of a LT compound stimulus
For 1 group of pigeons, reinforcement was foodFor the other group of pigeons, reinforcement was theavoidance of shock
5
10
15
Meanresponses
Tone
Shock-avoidancereinforcement
Foodreinforcement
Light Tone + Light
Foree & LoLordo (1973)
Pigeons trained with food reinforcement responded muchmore when tested with the light alone than when tested with the tone alone
Pigeons trained with shock-avoidance reinforcement responded much more when tested with the tone alone than when tested with the light alone
Selective association?
Dobrzecka, Szwejkowska, & Konorski (1966)
Buzzer
Raise left leg
Metronome
Raise right leg
Buzzer
Raise leg(go)
Metronome
Do notraise leg(no go)
Group 1(right/left discrimination)
Group 2(go/no go discrimination)
Training
TestingBuzzer
Raised left leg
Metronome
Raised right leg
Buzzer
Did notraise leg
Metronome
Raised leg
Dobrzecka, Szwejkowska, & Konorski (1966)
Two components to the auditory cues: - quality - location
Dogs trained on the left/right discrimination respondedmainly on the basis of the location of the auditory cues
Dogs trained on the go/no go discrimination respondedmainly on the basis of the quality of the auditory cues
Selective association?
Stimulus elements versus configural cues
So far, we’ve assumed that subjects treat stimulus elements as distinct and separate features of the environment (i.e., quality and location of sounds)
However, subjects could treat a complex stimulus as an integral whole that is not divided into parts or elements
Stimulus-element approach
Configural-cue approach
Learning Factors in Stimulus Control
Effects of Training on Generalization and Discrimination
- Intradimensional Training: * reinforced in the presence of S+ and not reinforced in the presence of
S-
Nondifferential Training :
- S+ always present. Differential (or Discrimination) Training: - Presence/Absence Training:
* reinforced in the presence of S+, not in its absence.
More peaked gradient
Flat gradient
Most peaked gradient
Less generalization; more discrimination
Least generalization; most discrimination
Non-Differential
Presence/Absence
Intradimensional
What is learned in discrimination training?
respond during the S+ do not respond during the S- or both (i.e., Spence)
Contextual Cues and Conditional Relations
Control of behavior by discrete stimuli (i.e., L or T)- discrete cues are those which are present for a
brief time and have a clear beginning and end
Contextual cues are the visual, auditory, and olfactorycues of the room or place where the discrete stimuli are presented
Contextual cues can provide an additional source ofcontrol of learned behavior
Conditioned Place Preference
Control by Contextual Cues
barrier
Rats given drugand put in Black side
Rats given salineand put in White side
On test:Barrierremoved
Rats placed in the center
On test:
Rats spend more time in drug paired context
Contextual cues can control behavior if they serve as a signal for a US or reinforcer
- experiment by Akins (1998) described on p. 243
Do contextual cues control behavior when they serve asbackground rather than explicit signal for reinforcer?
Experiment by Thomas, McKelvie, & Mah (1985)
Trained pigeons on a line-orientation discrimination in context 1
Context 1:S+ = vertical line (90º)S- = horizontal line (0º)
After the discrimination was learned, the context was changed andthe discrimination training contingencies were reversed
Context 2:S+ = horizontal line (0º)S- = vertical line (90º)
After learning the second problem, pigeons given generalizationtests in which lines of orientation between 0º and 90º were presentedin the two contexts
10
20
30
0 15 30 45 60 75 90
Responses
Line angle(degrees)
S+ S-Context 1 90 0Context 2 0 90
Results:
Thomas et al (1985) showed that: contextual cues can come to control instrumentalbehavior contextual control can occur without one context being more strongly associated with reinforcementthan the other direct associations between context and reinforcercannot explain the pattern of results each context associated with a different S+/S-contingency
Conditional Relations
Control by Conditional Relations
Binary relations:
S-R S-O R-O
In some cases the nature of a binary relation isdetermined by a third event = modulator
S-(R-O)
This is termed a conditional relation
S+/S- discriminations are conditional relations
Conditional Control in Pavlovian Conditioning
Rescorla, Durlach, & Grau (1985)
Reinforced trialsNoiseKey light - food
Nonreinforced trialsNo NoiseKey light – no food
20
40
60
80
Trials
Responsesper min
Element Compound
Conditional Control in Pavlovian Conditioning
In instrumental conditioning, modulators (i.e., S+ and S-)are called discriminative stimuli
In Pavlovian conditioning, modulators are called facilitators or occasion setters
A positive occasion setter signals that a CS-US contingency is in effect
A negative occasion setter signals that a CS-US contingency is not in effect
Positive Occasion Setting (Facilitation)
Training
If Occasion Setter is present:then CS USIf Occasion Setter is absent:
then CS no USResult
Thus CS CR only when Occasion Setter is present
Distinction between excitation and modulation
1. CS signals US; BUT occasion setter signals the relationship (if - then) between CS and US.
2. CS elicits CR; BUT occasion setter does not elicit a CR
3. CS does not facilitate responding to a new CS+; BUT an occasion setter can.
4. CS can support second order conditioning, BUT occasion setter does not.
5. CS presented alone results in extinction of CR; BUT occasion setter presented alone, no extinction of CS CR
Training
If Occasion Setter is present:then CS no USIf Occasion Setter is absent:then CS US
ResultThus CS CR only when Occasion Setter is absent – is this familiar?
Negative Occasion Setting
Conditioned Inhibition may be opposite of facilitation, not excitation
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