Download Skinner and Operant Conditioning

Skinner and Operant Conditioning
Slide One:
Two characteristics help us distinguish between the two forms of associative learning.
As you learned in classical conditioning, the organism learns associations between
events that the organism does not control, and responses are automatic. This is also
known as respondent behavior. Operant conditioning differs from classical conditioning
in that the organism learns associations between its behavior and resulting events. In
other words, the organism - you - operates on the environment. This is known as
operant behavior.
Slide Two:
Edward Thorndike’s law of effect states that rewarded behavior is likely to recur. In
1898 Thorndike used a fish reward to entice cats to find their way out of a puzzle box.
Over time and with experience, the cats’ performances tended to improve with each
successive trial; hence, Thorndike’s law of effect.
Skinner explored Thorndike’s law of effect. Skinner used an operant chamber, also
known as a Skinner box, in his pioneering studies with rats and pigeons. In these
studies, Skinner explored the precise conditions that foster efficient and enduring
learning, as the rat presses a bar for a food or water reward. Not shown is a measuring
device outside the box to record the animal’s accumulated responses.
Slide Three:
Skinner’s experiments used shaping. Shaping is a procedure using reinforcers, such as
food, to gradually guide an animal’s actions toward a desired behavior. The picture
above illustrates how rats have been shaped to save lives. This Gambian giant pouched
rat was shaped to sniff out land mines by receiving a banana after successfully locating a
mine during training in Mozambique. Shaping occurs by rewarding responses that are
ever closer to the final desired behavior, known as successive approximations, and
ignoring all other responses. In this way, researchers can gradually shape complex
behaviors. Even nonverbal animals and you as a baby could respond only to what you
perceived. Your reactions demonstrate which events you can discriminate.
Slide Four:
All human behavior is shaped with reinforcers. A reinforcer is any event that increases
the frequency of a preceding response. Reinforcers can be positive by presenting a
pleasant stimulus after a response, such as your approving smile after a cute boy says
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hello. Reinforcers can also be negative by reducing or removing an unpleasant stimulus,
such as smoking a cigarette to reduce a nicotine addict’s pangs.
Primary reinforcers, such as food when we are hungry, are innately satisfying.
Conditioned reinforcers, such as cash, are satisfying because we have learned to
associate them with more basic rewards. Immediate reinforcers, such as the caffeine
addict’s espresso coffee, offer immediate payback. Delayed reinforcers, such as a
weekly paycheck, require the ability to delay gratification. We may be more inclined to
engage in small immediate reinforcers (watching TV) than large delayed reinforcers
(Getting an A in a course) which requires consistent study.
Slide Five:
When the desired response is reinforced every time it occurs, continuous reinforcement
is involved. Learning is rapid, but so is extinction if rewards cease. Partial (intermittent)
reinforcement produces slower acquisition of the target behavior than continuous
reinforcement, but the learning is more resistant to extinction. Reinforcement schedules
may vary according to the number of responses rewarded or the time gap between
responses.
Fixed-ratio schedules reinforce behavior after a set number of responses; variable-ratio
schedules provide reinforcers after an unpredictable number of responses. Fixedinterval schedules reinforce the first response after a fixed time interval, and variableinterval schedules reinforce the first response after varying time intervals.
Slide Six:
Punishment, positive or negative, attempts to decrease the frequency of a behavior.
Positive punishment, as in light spanking, administers an undesirable consequence. A
negative punishment, like taking away a favorite toy, withdraws something desirable.
Negative reinforcement (like taking an aspirin) removes something undesirable, such as
a headache, to increase the frequency of a behavior (taking aspirin when you experience
another headache.) Notice that negative reinforcement increases the likelihood that a
behavior will occur while a punishment eliminates a behavior.
Punishment is not the opposite of reinforcement, because it can have several
undesirable side effects, including suppressing rather than changing unwanted
behaviors, teaching aggression, creating fear, and fostering feelings of helplessness.
Slide Seven:
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Rats exploring a maze seem to develop a mental representation, known as a cognitive
map, of the maze even in the absence of rewards. A rat’s latent learning becomes
evident only when there is some incentive to demonstrate it.
Research indicates that people may come to see rewards, rather than intrinsic interest,
as the motivation for performing a task. Again, this finding demonstrates the
importance of cognitive processing in learning. By undermining intrinsic motivation -the desire to perform a behavior for its own sake -- rewards can carry hidden costs.
Extrinsic motivation is the desire to perform a behavior because of promised rewards or
threats of punishment. A person’s interest often survives when a reward is used neither
to bribe nor coerce but to signal a job well done. Famous golfer Tiger Woods plays golf
for intrinsic motivation to win the most golf tournaments in history. Tiger Woods earns
enormous external monetary rewards re-writing history.
Slide Eight:
Skinner has been criticized for repeatedly insisting that external influences, not internal
thoughts and feelings, shape behavior, and for urging the use of operant principles to
control people’s behavior. Critics argue that he dehumanized people by neglecting their
personal freedom and by seeking to control their actions. Skinner countered that
people’s behavior is already controlled by external reinforcers, so why not administer
those consequences for human betterment?
Operant principles have been applied in a variety of settings. For example, in schools,
on-line testing systems and interactive student software embody the operant ideal of
individualized shaping and immediate reinforcement. In sports, coaches can build
players’ skills and self-confidence by rewarding small improvements. In the workplace,
positive reinforcement for jobs well done has boosted employee productivity. At home,
people’s use of energy has been decreased by altering the consequences and providing
feedback. Parents can reward behaviors that are desirable and not those that are
undesirable. To reach our personal goals, we can monitor and reinforce our own desired
behaviors and cut back on incentives as the behaviors become habitual.
Both classical and operant conditioning are forms of associative learning. They both
involve acquisition, extinction, spontaneous recovery, generalization, and
discrimination. Both classical and operant conditioning are influenced by biological and
cognitive predispositions. The two forms of learning differ in an important way. In
classical conditioning, organisms associate different stimuli that they do not control, and
respond automatically. In operant conditioning, organisms associate their own
behaviors with their consequences.
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Slide Nine:
Associative learning
Operant conditioning
learning that certain events occur together
a type of learning in which behavior is strengthened if followed
by a reinforcer or diminished if followed by a punisher
Respondent behavior
behavior that occurs as an automatic response to some
stimulus; Skinner’s term for behavior learned through classical
conditioning
Operant behavior
behavior that operates on the environment, producing
consequences
Law of effect
Thondike’s principle that behaviors followed by favorable
consequences become more likely, and that behaviors
followed by unfavorable consequences become less likely
Operant chamber
a chamber also known as a Skinner Box, containing a bar or key
that an animal can manipulate to obtain a food or water
reinforcer, with attached devices to record the animal’s rate of
bar pressing or key pecking; used in operant conditioning
research
Learning
a relatively permanent change in an organism’s behavior due
to experience
Shaping
an operant conditioning procedure in which reinforcers guide
behavior toward closer and closer approximations of the
desired behavior
Reinforcer
in operant conditioning, any event that strengthens the
behavior it follows
Positive reinforcement increasing behaviors by presenting positive stimuli, such as
food
Negative
increasing behaviors by stopping or reducing negative stimuli,
reinforcement
such as a shock
Primary reinforcer
an innately reinforcing stimulus, such as one that satisfies a
biological need
Conditioned reinforcer a stimulus that gains its reinforcing power through its
associations with a primary reinforcer; also known as a
secondary reinforcer
Continuous
reinforcing the desired response every time it occurs
reinforcement
Partial (intermittent)
reinforcing a response only part of the time; results in slower
reinforcement
acquisition of a response but much greater resistance to
extinction than does continuous reinforcement
Fixed-ratio schedule
in operant conditioning, a reinforcement schedule that
reinforces a response only after a specified number of
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Variable-ratio
schedule
Fixed-interval
schedule
Variable-interval
schedule
Punishment
Cognitive map
Latent learning
Intrinsic motivation
Extrinsic motivation
responses
in operant conditioning, a reinforcement schedule that
reinforces a response after an unpredictable number of
responses
in operant conditioning, a reinforcement schedule that
reinforces a response only after a specified time has elapsed
in operant conditioning, a reinforcement schedule that
reinforces a response at unpredictable time intervals
an event that decreases the behavior that it follows
a mental representation of the layout of one’s environment
learning that occurs but is not apparent until there is an
incentive to demonstrate it
a desire to perform a behavior for its own sake
a desire to perform a behavior due to promised rewards or
threats of punishment
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