Transcript Edward L. Thorndike

Edward L. Thorndike
• Animals placed in
puzzle boxes
• String pulled, latch
released, animal jumps
out and receives food
• Learning by random
trial and error
• Law of Effect –
Thorndike’s principle
that responses are
“stamped in” by
rewards and “stamped
out” by punishments.
B.F. Skinner
• “Project Pigeon” –WWII Skinner
suggested that pigeons be used to
guide missiles to their targets
• Operant – voluntary responses that
are reinforced
– Pecking at targets projected onto a
screen
• Reinforce – To follow a response
with a stimulus that increases the
frequency of the response
– Food pellets
• Defense Department concluded that
Project Pigeon was “for the birds”
Skinner Box
CC vs. OC
• Operant conditioning investigates the influence of
consequences on subsequent behavior.
• Classical conditioning looks at conditioned
involuntary responses such as eyeblinks or
salivation, whereas Operant conditioning
investigates the learning of voluntary responses
such as pecking at a target or pressing a lever.
• Where classical conditioning illustrates S-->R
learning, operant conditioning is often viewed as
R-->S learning.
• It is the consequence that follows the response that
influences whether the response is likely or unlikely
to occur again.
B.F. Skinner
• Skinner Box – experimental
conditions carefully introduced and
removed and results on laboratory
animals carefully observed.
• Rat deprived of food and placed in
Skinner box with lever at one end
• Rat accidentally presses lever and
food pellet is released.
• After trial and error the rat begins
pressing the lever to receive food.
• What is the operant?
– Pressing the lever
• What reinforces the behavior?
– Food pellet
Types of Reinforcers
• Positive Reinforcers – A reinforcer that when
presented increases the frequency of an
operant.
• Ex. A hungry rat presses a bar in its cage and
receives food. The food is a positive condition
for the hungry rat. The rat presses the bar again,
and again receives food. The rat's behavior of
pressing the bar is strengthened by the
consequence of receiving food.
Types of Reinforcement
• Negative Reinforcers – A reinforcer that when
removed increases the frequency of an operant.
• Ex. A rat is placed in a cage and immediately
receives a mild electrical shock on its feet. The
shock is a negative condition for the rat. The rat
presses a bar and the shock stops. The rat
receives another shock, presses the bar again,
and again the shock stops. The rat's behavior of
pressing the bar is strengthened by the
consequence of stopping the shock.
Positive or Negative
Reinforcement?
1.
2.
3.
4.
5.
6.
7.
8.
Police pulling drivers over and giving prizes for
buckling up.
A child snaps her fingers until her teacher calls on
her.
A hospital patient is allowed extra visiting time after
eating a complete meal.
Receiving a city utility discount for participating in a
recycling program.
Grounding a teenager until his/her homework is
finished.
A parent nagging a child to clean up her room.
A rat presses a lever to terminate a shock or a loud
tone.
A professor gives extra credit to students with
perfect attendance.
1.
PR
2.
NR
3.
PR
4.
PR
5.
6.
7.
NR
NR
NR
8.
PR
Types of Reinforcers
• Primary Reinforcers
– An unlearned
reinforcer.
• Ex. Food, water,
adequate warmth
(positive reinforcers)
and pain (negative
reinforcer)
• Secondary
Reinforcers – A
stimulus that gains
reinforcement value
through association
with established
reinforcers.
• Ex. Money, attention,
social approval
POSITIVE REINFORCERS
NEGATIVE REINFORCERS
PRIMARY
SECONDARY
PRIMARY
SECONDARY
Food
Money
Electric shock
Rejection
Water
Grades
Intense heat
Failure
Sex
Status
Pain of any
sort
Criticism
Warmth
Praise
Suffocation
Avoidance
Rewards and Punishments
• Reward – A pleasant
stimulus that
increases the
frequency of the
behavior it follows.
• Considered to
synonymous with
positive
reinforcement.
• Punishment – An
unpleasant stimulus
that suppresses the
behavior it follows.
• Usually better to
reward children for
desirable behavior.
• Pg. 160
Potential Negative Effects of Punishment
Recurrence
of undesirable
employee behavior
Undesirable
emotional reaction
Antecedent
Undesirable
employee
behavior
Punishment
by
manager
But
Short-term
leads
to
decrease in
frequency long-term
of
undesirable
employee
behavior
Aggressive,
disruptive
behavior
Apathetic,
noncreative
performance
Fear of
manager
Which tends
to reinforce
High turnover
and absenteeism
Schedules of Reinforcement
• Continuous Reinforcement
– A schedule of reinforcement
in which every correct
response is reinforced.
• Partial Reinforcement – One
of several reinforcement
schedules in which not every
correct response is reinforced.
• Which method do you think is
used more in real life?
An Example of Continuous
Reinforcement
• Each instance of a smile is reinforced
Schedules of Reinforcement
• Continuous
reinforcement refers
to reinforcement
being administered to
each instance of a
response
• Partial reinforcement
lies between
continuous
reinforcement and
extinction
Schedules of Reinforcement
• Ratio Version –
having to do with
instances of the
behavior.
• Ex. – Reinforce or
reward the behavior
after a set number or
x many times that an
action or behavior is
demonstrated.
• Interval Version –
having to do with the
passage of time.
• Ex. – Reinforce the
student after a set
number or x period of
time that the behavior
is displayed.
4 Basic Schedules of
Reinforcement
• Fixed-interval
schedule
• Variable-interval
schedule
• Fixed-ratio
schedule
• Variable-ratio
schedule
Fixed-Interval Schedule
• Fixed-interval schedule – A schedule in which
a fixed amount of time must elapse between the
previous and subsequent times that
reinforcement will occur.
• No response during the interval is reinforced.
• The first response following the interval is
reinforced.
• Produces an overall low rate of responding
• Ex. I get one pellet of food every 5 minutes
when I press the lever
Fixed Interval Reinforcement
Variable-Interval Schedule
• Variable-interval Schedule – A schedule
in which a variable amount of time must
elapse between the previous and
subsequent times that reinforcement is
available.
• Produces an overall low consistent rate of
responding.
• Ex. – I get a pellet of food on average
every 5 minutes when I press the bar.
Variable Interval Reinforcement
Fixed-Ratio Schedule
• Fixed-ratio Schedule – A schedule in which
reinforcement is provided after a fixed number of
correct responses.
• These schedules usually produce rapid rates of
responding with short post-reinforcement
pauses
• The length of the pause is directly proportional
to the number of responses required
• Ex. – For every 5 bar presses, I get one pellet of
food
An Example of Fixed Ratio
Reinforcement
• Every fourth instance of a smile is reinforced
Fixed Ratio Reinforcement
Variable-Ratio Schedule
• Variable-ratio Schedule – A schedule in
which reinforcement is provided after a
variable number of correct responses.
• Produce an overall high consistent rate of
responding.
• Ex. – On average, I press the bar 5 times
for one pellet of food.
An Example of Variable Ratio
Reinforcement
• Random instances of the behavior are
reinforced
Variable Ratio Reinforcement
TYPE
MEANING
OUTCOME
Fixed
Ratio
Reinforcement depends
on a definite number of
responses
Activity slows after
reinforcement and
then picks up
Variable
Ratio
Number of responses
needed for
reinforcement varies
Greatest activity of
all schedules
Fixed
Interval
Reinforcement depends
on a fixed time
Activity increases
as deadline nears
Variable
Interval
Time between
reinforcement varies
Steady activity
results
Comparisons of Schedules of Reinforcement
FORM OF
REWARD
INFLUENCE ON
PERFORMANCE
Fixed interval
Reward on fixed
time basis
Leads to average
and irregular
performance
Fast extinction of
behavior
Fixed ratio
Reward tied to
specific number of
responses
Leads quickly to
very high and
stable
performance
Moderately fast
extinction of
behavior
Variable interval
Reward given after
varying periods of
time
Leads to
moderately high
and stable
performance
Slow extinction of
behavior
Variable ratio
Reward given for
some behaviors
Leads to very high
performance
Very slow
extinction of
behavior
SCHEDULE
EFFECTS ON
BEHAVIOR
FI, VI, FR, or VR?
1.
2.
3.
4.
5.
When I bake cookies, I can only put one set in at a time,
so after 10 minutes my first set of cookies is done. After
another ten minutes, my second set of cookies is done.
I get to eat a cookie after each set is done baking.
After every 10 math problems that I complete, I allow
myself a 5 minute break.
I look over my notes every night because I never know
how much time will go by before my next pop quiz.
When hunting season comes around, sometimes I’ll
spend all day sitting in the woods waiting to get a shot
at a big buck. It’s worth it though when I get a nice 10
point.
Today in Psychology class we were talking about
Schedules of Reinforcement and everyone was eagerly
raising their hands and participating. Miranda raised her
hand a couple of times and was eventually called on.
1. FI
2. FR
3. VI
4. VI
5. VR
FI, VI, FR, or VR?
6. Madison spanks her son if she has to ask him three
times to clean up his room.
7. Emily has a spelling test every Friday. She usually does
well and gets a star sticker.
8. Steve’s a big gambling man. He plays the slot
machines all day hoping for a big win.
9. Snakes get hungry at certain times of the day. They
might watch any number of prey go by before they
decide to strike.
10. Mr. Vora receives a salary paycheck every 2 weeks.
t
11. Christina works at a tanning salon. For every 2 bottles
of lotion she sells, she gets 1 dollar in commission.
12. Mike is trying to study for his upcoming Psychology
quiz. He reads five pages, then takes a break. He
resumes reading and takes another break after he has
completed 5 more pages.
6. FR
7. FI
8. VR
9. VI
10. FI
11. FR
12. FR
FI, VI, FR, or VR?
13. Megan is fundraising to try to raise money so she can
go on the annual band trip. She goes door to door in
her neighborhood trying to sell popcorn tins. She
eventually sells some.
14. Kylie is a business girl who works in the big city. Her
boss is busy, so he only checks her work periodically.
15. Mark is a lawyer who owns his own practice. His
customers makes payments at irregular times.
16. Jessica is a dental assistant and gets a raise every year
at the same time and never in between.
17. Andrew works at a GM factory and is in charge of
attaching 3 parts. After he gets his parts attached, he
gets some free time before the next car moves down
the line.
18. Brittany is a telemarketer trying to sell life insurance.
After so many calls, someone will eventually buy.
13. VR
14. VI
15. VI
16. FI
17. FR
18. VR
Applications of Operant
Conditioning
• Programmed
Learning – A method
of learning in which
complex tasks are
broken down into
simple steps, each of
which is reinforced.
Errors are not
reinforced.
• Ex. – Hooked on
Phonics
Applications of Operant
Conditioning
• Socialization – Guidance of
people into socially desirable
behavior by means of verbal
messages, the systematic
use of rewards and
punishments, and other
methods of teaching.
• Ex. – Children play with other
children who are generous
and non-aggressive and
avoid those who are not.
Applications of Operant
Conditioning
• Behavior Modification
Praise this
Ignore this
Applications of Operant
Conditioning
• Token Economy –
An environmental
setting that fosters
desired behavior by
reinforcing it with
tokens (secondary
reinforcers) that can
be exchanged for
other reinforcers.
• Ex. – Book It!
Other Types of Learning
• Insight Learning – In Gestalt psychology,
a sudden perception of relationships
among elements of the “perceptual field”,
permitting the solution of a problem.
• Latent Learning – Learning that is hidden
or concealed.
• Observational Learning – Acquiring
operants by observing other engage in
them.
Insight Learning
• Wolfgang Kohler –
German Gestalt
psychologist
• Experiments with
Chimpanzees
• Sultan learned to use a
stick to rake in bananas
placed outside his cage.
• When the bananas were
placed outside of Sultan’s
reach, he fitted two poles
together to make a single
pole long enough to
reach the food
Insight Learning
• “Aha” Learning
• Cognitive Map – A mental
representation or “picture”
of the elements in a
learning situation, such as
a maze.
– Ex. – if someone pukes in
the hall that you usually take
to your next class you will
still be able to find your way
because of your mental
representation of this
school.
Insight Learning
Latent Learning
• E.C. Tolman – experiment with
rats.
• Rats learn about their
environments in the absence of
reinforcement.
• Some rats went through maze
for food goals, while others were
given no reinforcement for
several days.
• After 10 days, rewards were put
in with the rats that had
previously been given no
rewards for 2 or 3 trials.
• Those rats reached the food box
as quickly as the rats that had
been getting reinforcement for
over a week.
• Rats learn about mazes in which
they roam even if they are
unrewarded for doing so.
Observational Learning
•
•
•
•
•
Albert Bandura
Bobo doll experiment
Assistant placed in room with doll
Beat doll with hammer and hit doll
Kindergarten children watched this
display of aggression in a separate
room.
• When placed in the room, they too
were extremely aggressive with the
doll
• Happened without ever being
rewarded for the behavior.
• http://www.npr.org/templa
tes/story/story.php?storyI
d=1187559
•Modeling
Monkey see, monkey do!
•Disinhibition
Get away with or are rewarded for violence
They always “get the girl/guy/money/car - etc.
•Increased arousal
Works the audience up
Watch the fans at a sporting event
Watch your friends watch the WWF
•Habituation
We become used to - desensitization
1. Violent behavior is not representative of most people
2. Violent behaviors are not real - special effects and technology
3. Most people use other than non-violent means to resolve conflict
Mediation
Arbitration
Negotiation
Other
•Positive modeling
•Abiding by rating system
•Encourage other activities
•Act - call legislators
•Monitor - watch first, watch with, explain
•Limit time
•Watch educational programs