Download Avoidance Conditioning

Combining Classical and
Operant Conditioning
Avoidance Conditioning
Classical and operant conditioning often take place in
the same situation.
We saw this in Rescorla’s fear conditioning experiment:
Presenting a CS while dogs jumped back and forth to
avoid shock increased or decreased the rate of
jumping.
In Rescorla’s experiment, the avoidance procedure
(operant conditioning) had no warning signal for the
shocks; they came at certain times.
In another type of avoidance procedure, signalled
avoidance, there is a warning signal before the shock.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
Signalled Avoidance
Warning
signal
(tone)
Avoidance
response
Aversive
stimulus
(shock) If there is no avoidance response, the warning
signal ends with shock.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
Signalled Avoidance
Warning
signal
(tone)
Aversive
stimulus
(shock)
Note that the warning signal is paired with shock.
This is classical conditioning. The tone will become
a CS and produce a CR of fear.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
Signalled Avoidance
Warning
signal
(tone)
Aversive
stimulus
(shock)
Key Point: The warning signal will become an
aversive stimulus because it produces a fear CR.
Aversive stimuli are negative reinforcers. They reinforce
responses that remove them.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
Signalled Avoidance
Warning
signal
(tone)
Avoidance
response
Aversive
stimulus
(shock) If the avoidance response occurs before the
shock, the tone goes off immediately and no
shock is given on that trial.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
Signalled Avoidance
Warning
signal
(tone)
Avoidance
response
Removal of the aversive warning signal negatively
reinforces the avoidance response.
The avoidance response occurs faster and faster on later
trials because it receives negative reinforcement.
This is operant conditioning.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
The 2-Process Theory of Avoidance Learning
Avoidance behavior is not reinforced by avoidance of
the aversive stimulus!
It is reinforced by termination of the warning signal.
Process 1: Classical Conditioning: The warning
signal becomes aversive through pairings with the
aversive stimulus (fear conditioning).
Process 2: Operant Conditioning: Avoidance
responses are negatively reinforced by
termination of the warning signal.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
The 2-Process Theory of Avoidance Learning
Pros
Key prediction: Delay of reinforcement weakens
behavior. When an avoidance response occurs, if the
warning signal goes off after a delay, the avoidance
response should occur less often.
Warning
signal
(tone)
Avoidance
response
Delay of reinforcement
This prediction was supported (Kamin, 1956).
Combining Classical and
Operant Conditioning
Avoidance Conditioning
The 2-Process Theory of Avoidance Learning
Cons
1. Unsignalled avoidance: Avoidance learning can
take place without a warning signal (e.g., Rescorla’s
experiment).
2. No extinction of avoidance response: Avoidance
responding should stop because the warning signal is
not paired with shock on these trials, but the
avoidance response keeps going. Why?
Combining Classical and
Operant Conditioning
Avoidance Conditioning
Cognitive Theory of Avoidance Learning
The subject forms two kinds of “expectancies”:
1. Stimulus-Outcome: Warning signal leads to shock
if there is no response.
2. Response-Outcome: Avoidance response leads to
safety (no shock).
To weaken avoidance response, these expectancies
must be weakened through disconfirmation.
Avoidance response keeps going because Expectancy
#1 not tested and Expectancy #2 is repeatedly
confirmed.
Combining Classical and
Operant Conditioning
Avoidance Conditioning
Cognitive Theory of Avoidance Learning
Supporting evidence: Response Prevention ( “Flooding”)
procedure. It’s used to eliminate an avoidance response
when there is no longer a threat of being shocked.
Physically prevent the subject from making the
avoidance response while the warning signal is on. New
expectancies are formed:
1. Stimulus-Outcome: Warning signal leads to NO
shock if there is no response.
2. Response-Outcome: NOT responding leads to
safety.