Download Unit 6 Learning

11/13/13
How do we learn?
 Brainstorm, what are some ways we learn new
information?
 Do we learn similarly to any other animals?
 Does everybody learn the same way?
How we Learn
 Learning: A relatively permanent change in an
organism’s behavior due to experience.
 Habituation: an organism’s decreasing response to a
stimulus with repeated exposure to it.
 Associative learning: Learning that certain events
occur together. The events maybe two stimuli or a
response and its consequences
Learning and Conditioning
 Learning - A relatively permanent
change in behavior due to experiences
 Conditioning – The acquisition of
specific patterns of behavior in the
presence of well-defined stimuli
 Classical and Operant
Classical Conditioning
 Stimulus = cause
 Response = effect
Ivan Pavlov (1849–1936)
Elements of Classical Conditioning
 Neutral Stimulus (NS)
 Unconditioned Stimulus (US)
 Unconditioned Response (UR)
 Conditioned Stimulus (CS)
 Conditioned Response (CR)
Neutral Stimulus—Bell
Does not normally cause a
response or reflex action by itself
 a bell ringing
 a color
 a furry object
Unconditioned Stimulus—Food
Always cause a reflex action
 food
 blast of air
 noise
Unconditioned Response - Salivation
A response to an unconditioned
stimulus—naturally occurring
reflex
 Salivation at smell of food
 Eye blinks at blast of air
 Startle reaction in babies
Conditioned Stimulus
The learned (once neutral)
stimulus
 The tone of the bell causes salivation
Will eventually elicit the
unconditioned response by itself
Conditioned Response
The original unconditioned
response becomes conditioned
after it has been elicited by the
neutral stimulus
Salivation because of the bell tone
Classical Conditioning in Humans
 Watson and Little
Albert
 Identify the:
 Neutral Stimulus
 Unconditioned
Stimulus
 Unconditioned
Response
 Conditioned Stimulus
 Conditioned Response
 Is this Ethical?
Identify the:
 Neutral Stimulus (NS)
 Unconditioned Stimulus (US)
 Unconditioned Response (UR)
 Conditioned Stimulus (CS)
 Conditioned Response (CR)
Classical Conditioning
 Acquisition: in classical conditioning, the stage when
links a neutral stimulus and an unconditioned stimulus are
linked so that the neutral stimulus begins triggering the
conditioned response.
 Higher-order conditioning: a procedure in which the
conditioned stimulus in one conditioning experience is
paired with a new neutral stimulus, creating a second
(often weaker) conditioned stimulus.
 For example, an animal that has learned that a tone predicts
food might then learn that a light predicts the tone and begin
responding to the light alone. (Also called second-order
conditioning.)
 Extinction: the diminishing of a conditioned
response; occurs in classical conditioning when an
unconditioned stimulus (US) does not follow a
conditioned stimulus (CS); occurs in operant
conditioning when a response is no longer reinforced.
 Spontaneous recovery: the reappearance, after a
pause, of an extinguished conditioned response.
 Generalization: the tendency, once a response has
been conditioned, for stimuli similar to the
conditioned stimulus to elicit similar responses.
 Discrimination: in classical conditioning, the learned
ability to distinguish between a conditioned stimulus
and stimuli that do not signal an unconditioned
stimulus.
Cognitive Processes
 Early behaviorists believed that learned behaviors of
various animals could be reduced to mindless
mechanisms.
 However, later behaviorists suggested that animals learn
the predictability of a stimulus, meaning they learn
expectancy or awareness of a stimulus (Rescorla, 1988).
 Learned Helplessness
 Not just the conditioning, the thought influences
behavior as well
Biological Predispositions
 Pavlov and Watson believed that laws of learning were
similar for all animals. Therefore, a pigeon and a person
do not differ in their learning.
 However, behaviorists later suggested that learning is
constrained by an animal’s biology.
 Each species’ predispositions prepare it to learn the
associations that enhance its survival.
Biological Predispositions
Courtesy of John Garcia
Garcia showed that the duration between the CS
and the US may be long (hours), but yet result in
conditioning. A biologically adaptive CS (taste)
led to conditioning and not to others (light or
sound).
Taste Aversion
John Garcia
Biological Predispositions
Even humans can develop classically to
conditioned nausea.
Operant Conditioning
 Classical Conditioning involves respondent behavior




(automatic actions)
Operant conditioning reinforces desired behavior and
discourages undesired behavior.
Operant behavior: Behavior that operates (has an
effect) on the environment to produce consequences
Classical conditioning=no control
Operant conditioning= control of behavior and
consequences
Operant Conditioning
 Law of effect: rewarded behavior is likely to recur
(Edward Thorndike)
 Skinner used the Law of Effect to develop principles of
behavior control.
 Operant chamber/Skinners box: box containing a bar
or key that an animal can use to obtain a food or water
reinforcer; attached devices record rate of bar or key
pressing
 Shaping: reinforcers guide behavior toward desired
behavior with successive approximations
 Discriminative Stimulus: elicits response after
association with reinforcement (remember
discrimination vs. generalization)
 Reinforcer: in operant conditioning, any event that
strengthens the behavior it follows.
 Positive Reinforcement: increasing behaviors by
presenting positive stimuli, such as food. A positive
reinforcer is any stimulus that, when presented after a
response, strengthens the response.
 Negative Reinforcement: increases behaviors by
stopping or reducing negative stimuli, such as shock.
A negative reinforcer is any stimulus that, when
removed after a response, strengthens the response
(Note: negative reinforcement is NOT punishment).
 Primary reinforcer: an innately reinforcer stimulus,
such as one that satisfies a biological need.
 Conditioned reinforcer: a stimulus that gains its
reinforcing power through its association with a
primary reinforcer; also known as a secondary
reinforcer.
Immediate and Delayed
Reinforcement
 Which one works better?
 In rats-immediate
 In humans- both will work, sometimes delayed works
better.
 If given the option of a small candy bar today or a big
candy bar tomorrow what would you choose?
Reinforcement Schedules
 Continuous reinforcement: Reinforcing the desired
response every time it occurs.
 Partial (intermittent) reinforcement: Reinforcing a
response only part of the time; results in slower
acquisition of a response but much greater resistance
to 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
participant 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
Very slow
Leads to very
high performance 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
Punishment
 While reinforcement increases behavior, punishment
does the opposite
 Punishment: An event that decreases the behavior that
it follows.
 Positive punishment: adding an aversive stimulus.
(spanking)
 Negative punishment: taking away desirable stimulus.
(grounded)
Biological Predispositions
 Biological constraints predispose organisms to learn
associations that are naturally adaptive.
 You can teach a pigeon to flap it’s wings to avoid shock
and to peck to receive food but not the other way
around.
Cognition & Operant Conditioning
Evidence of cognitive processes during operant
learning comes from rats during a maze
exploration in which they navigate the maze
without an obvious reward. Rats seem to
develop cognitive maps, or mental
representations, of the layout of the maze
(environment).
Cognitive map: a mental representation of the
layout of ones environment
Latent Learning
Such cognitive maps are based on latent
learning, which becomes apparent when an
incentive is given (Tolman & Honzik, 1930).
Motivation
Intrinsic Motivation:
The desire to perform a
behavior for its own
sake.
Extrinsic Motivation:
The desire to perform a
behavior due to
promised rewards or
threats of punishments.
Skinner’s Legacy
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.
Falk/ Photo Researchers,
.
Inc
Applications of Operant Conditioning
Skinner introduced the concept of teaching
machines that shape learning in small steps and
provide reinforcements for correct rewards.
LWA-JDL/ Corbis
In School
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. Bertani receives a salary paycheck every 2 weeks.
(Miss Suter doesn’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