Download Chapter 6 PPT Operant conditioning

Learning
Chapter 6
Definition: Learning
• “Learning” is defined in psychology as ‘a
relatively permanent behavior change as
a result of experience.
Classical Conditioning
This woman has now been conditioned to have a negative response to the
flash of light, even before or without the loud noise.
Operant Conditioning
• Classical conditioning involves respondent
behavior, an automatic response to a stimulus
• It involves operant behavior, which operates on
the environment, producing consequences
• Consequences: Reinforcers following a
behavior strengthen it (make that behavior more
likely to happen again), and Punishments
following a behavior weaken that response
(make it less likely to recur).
Operant Conditioning
(a) Response:
Balancing a ball
(b) Consequence:
Receiving Food
(c) Behavior stregthened
B. F. Skinner’s Experiments
• Skinner designed an operant chamber (aka
Skinner Box) – a box with a recording device to
track how often an animal presses a bar to
obtain reinforcement – any event or other
consequence that strengthens the behavior it
follows.
Reinforcement for the Individual
• What is reinforcing to
one individual?
• Can vary by situation –
a cold drink is
reinforcing if you are
hot, but not if you are
cold
Shaping Behavior
• Shaping: gradually guiding actions closer
and closer toward a desired behavior,
using reinforcement.
• Using successive approximations, one
rewards responses that are ever-closer to
the desired behavior.
• Through continued shaping we can find
the limits of animals’ ability to discriminate
among colors, smells, sounds.
Types of Reinforcers
• Positive reinforcement: (+, adding)
anything that strengthens a response
when presented after the response (e.g., a
food reward)
• Negative reinforcement: (-, taking away)
anything that, when removed, strengthens
a response (e.g., stopping a shock). Note:
NOT a punishment
• Big Bang Theory
Ways to Increase Behavior
Reinforcement Schedules
• Continuous reinforcement – reinforcing
desired response every time it occurs
– Learning occurs rapidly, but so does extinction
• Partial (intermittent) reinforcement –
reinforcing a response only part of the time
– Learning is slower but increased resistance to
extinction
Partial Reinforcement Schedules
for Operant Conditioning
• Fixed-ratio schedule – reinforces response
only after fixed number of responses
• Variable-ratio schedule – reinforces response
after an unpredictable number of responses
– Produces high rates of responding
• Fixed-interval schedule – reinforces response
only after a specified time has elapsed
– Produces choppy start-stop pattern
• Variable-interval schedule – reinforces
response at variable time intervals
– Produces slow, steady responding
Schedules of Reinforcement
Punishment
• A punishment is an event that decreases
the frequency of the behavior it follows
• Two Types of punishment:
– Positive (+, adding something) Punishment
– Negative (-, taking something away)
Punishment.”
Punishment
Skinner’s Legacy: Controversy
Skinner argued that behaviors were shaped by
external influences instead of inner thoughts and
feelings. Critics argued that Skinner
dehumanized people by neglecting their free will.
Applications of Operant Conditioning
• In school: use individualized shaping to
reinforce students starting with their
current level of performance.
• At work: reinforce, even with verbal
acknowledgement, specific behaviors and
achievements
• At home: be careful not to reward
tantrums and not to be negatively
reinforced by giving in.
Contrasting Classical and
Operant Conditioning
Biological Constraints on
Conditioning
• Natural selection favors traits that aid
survival.
• This applies to conditioning: Each species
comes prepared to learn those things
crucial to its survival.
Cognitive Processes and Classical
Conditioning
• Behaviorism: The view that (1) psychology
should be an objective science that (2) studies
behavior without reference to mental processes
– Founded by Pavlov, Watson, and Skinner
– Most psychologists today agree with (1) but not (2)
• Underestimates two important sets of influences:
– Biological predispositions limit our learning
– The effect of our cognitive processes on learning
Cognitive Processes and Operant
Conditioning
• B. F. Skinner tried to downplay the role of
cognitive processes. However, they
cannot be ignored
– Rats exploring a maze develop a cognitive
map, a mental representation of the maze.
– Rats with experience in the maze exhibit
latent learning of the maze’s layout
Cognitive Processes and Operant
Conditioning
• Excess rewards can destroy intrinsic
motivation, the desire to perform a
behavior for its own sake.
• This is in contrast to extrinsic motivation,
in which behavior is performed to gain
reward or avoid punishment.
Learning By Observation
• Cognition is a factor in observational
learning, in which humans and some
other animals learn without direct
experience – by watching and imitating
• Bobo doll