Transcript Chapter 4 Learning - Western Washington University

Instrumental Learning
• A general class of behaviors inferring that
learning has taken place
Two general classes of behaviors
• Free operants
• Fixed trials
The consequences of behavior
• The delivery of a reinforcement
1. Thorndike and the law of
effect
• That behavior that immediately preceded
the appearance of a satisfying state of
affairs (internal to the animal) is a
reinforcer
2. Skinner and Operant Behavior
V. Major phenomena of
instrumental learning
• Called operant because the animal
operates on the environment to acquire a
reinforcer
Conditioned reinforcement
• The animal only gets rewarded when an
explicit behavior is emitted.
• Acquiring money!!
Note the terms
• One rewards the animal.
• One reinforces a response.
What is a reinforced?
• The explicit narrow behavior that occurs
immediately preceding the delivery of the
reinforcement.
Reinforcement & Punishment
• Concept – Positive Reinforcement
Description
• Increasing the frequency of a behavior by
following it with the presentation of a
positive reinforcer – a pleasant, positive
stimulus or experience
Example
• Saying “Good job” after someone works
hard to perform a task.
Types of reinforces
• Appetitive – usually food
• Negative --- shock, air puff; those stimuli
that deliver pain or discomfort.
Positive Reinforcement
Concept:
• Negative reinforcer
Negative Reinforcement
Note the following
• The removal of a negative stimulus is
positively reinforcing – the animal will tend
to do that behavior that removes itself from
the cues associated with the aversive
state of affairs.
The Skinner Box
• Any box or device in which a reinforcer
can be automatically delivered contingent
on the behavior of the animal.
Shaping
• The initial learning – teaching the animal
to hit a bar or push a key.
Accumulative record
• A “strip chart’s” ink record of the animals
behavior.
Schedules of reinforcement
• Reinforcement based on responses
• Reinforcement based on the passage of
time
Fixed Ratio Behavior (FR)
• Reinforcement based on the number of
response accomplished. For humans,
piece work – payment for the number of
things accomplished
Variable Ratio (VR)
• Payment (reinforcement) for the average
number of responses accomplished
Fixed Interval (FI)
• Reinforcement for the first response after
a fixed period of time has occurred.
• Work by the hour, irrespective of the
amount of work accomplished
Variable Interval (VI)
• Reinforcement based on the first response
after an average amount of time has
passed.
Interval schedules
Combinations of schedules of
reinforcement
• Unlimited combinations of schedules
Partial Reinforcement
• Variable ratio and variable interval
schedules are harder to extinguish than
continues reinforcement
Negative Control of Behavior
• Behavior emitted that removes an aversive
state of affairs.
Negative reinforcer
Description: Increasing the frequency of a
behavior by following it with the removal of
an unpleasant stimulus or experience
Concept
• Avoidance conditioning
Avoidance conditioning
• Description: Learning to make a response
that avoids an unpleasant stimulus.
Example
• You slow your car to the speed limit when
you spot a police car, thus avoiding being
stopped and reducing the fear of a fine;
very resistant to extinction
1. Escape and Avoidance
The control of Intrinsic behavior
• Avoidance tasks the removal of one-self
from an environment which has previously
been associated with a negative
reinforcement.
Sidman Avoidance
• Shock-Shock interval (shock every 5 sec)
S. A. (cont.)
• Response shock interval (time delay of
shock/bar push)
S. A. (cont.)
• Very, very hard to extinguish.
• VAN - chimp
VIII. Punishment – different
types
•
Punishment 2 (Penalty)
Example
• You learn to use the mute button on the
TV remote control to remove the sound of
an obnoxious commercial
Concept
• Escape Conditioning
Escape Conditioning
• Description: Learning to make a response
that removes an unpleasant stimulus
Example
• A little boy learns the crying will cut short
the time that he must stay in his room
Concept
• Punishment
Punishment
• Description: Decreasing the frequency of a
behavior by either presenting an
unpleasant stimulus (punishment 1) or
removing a pleasant one (punishment 2
(penalty).
Example
• You swat the dog after it steals food from
the table, or you take a favorite toy away
from a child who misbehaves. A number of
cautions should be kept in mind when
using punishment (see below for an
example).
Learned helplessness
• Continued punishment until the animal
refuses to respond even when there is no
aversive state of affairs.
Combined Operant and C. C.