Transcript Learning and Adaptation- Ch 7 psych1000midterm

Learning and Adaptation
Chapter 7
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Biology, cognition & culture
Adapting to the environment
Classical Conditioning
Operant Conditioning
Learning and the brain
Modelling
Observational learning
Biology, cognition & culture
• Theorized that the brain is prewired to learn
• Learning mechanisms help us respond to one
or more adaptation challenges
: is the decrease in response
strength to a repeated stimulus
– Not the same as sensory habituation!
– Habituation: simple form of learning
– Sensory Habituation: decreased sensory response
to a continuously present stimulus.
Adapting to the environment
• What is learning?
– Process by which experience produces a relatively
enduring change in beahviour or capabilities
• Measure learning by actual changes in
performance
• Can increase the strength of a response to a
repeated stimulus through
– Typically with strong or noxious stimuli
– Why? Increases response to potentially dangerous
stimuli.
Classical conditioning
https://www.youtube.com/watch?v=0asusjaYpe4
• 4 important elements: UCS, UCR, CR, CS
– Unconditioned Stimulus: elicits a reflective or innate
response without prior learning
– Unconditioned Response: reflexive or innate response
elicited by the UCS
– Conditioned Stimulus: through association with the
UCS comes to elicit a conditioned response similar to
the UCR
– Conditioned Response: response elicited by a
conditioned stimulus
Common Conditioning Procedures
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CS present when UCS is presented
Optimal learning
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CS appears then goes off, then start of UCS
Learning occurs if delay 2-3 sec or less
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CS and UCS presented at same time
Slow learning
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UCS presented before CS
Learning rarely occurs
Extinction
• Process in which CS is presented in absence of
UCS
• Causes CR to weaken and eventually
disappear
• *KEY*: repeated presentation of CS without
UCS
: after a rest period
without new learning the reappearance of a
previously extinguished CR
Factors that enhance Acquisition
• Multiple CS-UCS pairings
• Intense, aversive UCS can produce one-trial
learning
• Forward (short-delay) pairing
• Time interval between onset of CS & onset of UCS
is short
stimuli similar to initial CS elicits
a CR
: CR occurs to one stimulus but not
to another
Higher Order Conditioning
• Chain of events which has 2 CS stimuli
• Expands influence of classical conditioning on
behaviour
• Ex. Dog already CR to a bell which CS is
salivation.
– Pair the bell with a black square which will
eventually become a new CR and elicit the CS
• Conditioning a fear response
– Little albert
Applications to Daily Life
• Acquisition of Fetishes
- experiencing sexual attraction to nonliving
things
– Suggested that pairing neutral objects with sex can
lead to fetishes
• Acquisition- overcoming fear
• Extinction of CR through exposure to CS without presence of
UCS allowing extinction to occur
CTA vs. CTP
• CTA= Conditioned taste aversion
– Ex. Alcohol
– Can occur in clinical application
• Chemotherapy and radiation
• 50% of patients develop (ANV)
• CTP= Conditioned taste preferences
– Ex. buckleys
Operant conditioning
https://www.youtube.com/watch?v=Mt4N9GSBoMI
• Facilitates personal adaptation
– Response strengthened by outcomes that followed
– Response weakened by outcomes that follows
Law of Effect
– Response followed by a satisfying consequence
becomes more likely to occur
– Response followed by an unsatisfying
consequence becomes less likely to occur
• Based on concept of instrumental learning
– Behaviour is instrumental in bringing about
certain outcomes
Determining how to respond
• 2 types of reinforcements- strengthen
responses
– Positive and negative
• 2 types of punishments- weaken responses
– Positive and negative
Consequences
– Response is strengthened by presentation of a
stimulus that follows it
• 2 types:
: stimuli that are reinforcing
because they satisfy biological needs
: acquire reinforcing
properties through association with primary
reinforcers
Consequences
– Response weakened by subsequent stimulus
presentation
– Produces rapid results
– Response strengthened by removal (or avoidance)
of an aversive stimulus (negative reinforcer)
– Response weakened by removal of stimulus
Types of Reinforcement
– When a pleasant consequence follows a response,
making the response more likely to occur again
– Ex. Behaviour = studying; PR = good grade
– When a response is followed by the removal of
something unpleasant, making the response more
likely to occur again
– Ex. Behaviour = studying; NR= nagging stops
• **something is being applied or given
Types of Punishers
– When something unpleasant occurs after a behaviour
– Ex. Behaviour = studying; PP = ridicule by friends
– When something pleasant is removed after a
beahviour
– Ex. Behaviour = studying; NP = loose time with friends
• **something is being taken away
Immediate vs Delayed consequences
• Immediate
– Stronger effect on behaviour
• Delay of Gratification
– Involves ability to forego immediate reward for
more satisfying outcome later
– Kids show less D of G.
Shaping & Chaining
• Shaping
– Reinforce successive approximations toward a
final response
• Chaining
– Reinforce each response with opportunity to
perform the next response
– Develops a sequence of behaviours
Conseqeunces
– Weakening and eventual disappearance of an operant
response
– Resistance to extinction influences by pattern of
reinforcement that has maintained behaviour
– Operant response occurs to a new antecedent
stimulus or situation similar to the original one
– Operant response occurs to once antecedent stimulus
but not another
– A discriminative stimulus influences a behaviour
Schedules of Reinforcement
• Continuous reinforcement
– Every response of a particular type is reinforced
– Extinguishes very quickly
• Partial reinforcement
– Only some responses are reinforced
– 2 dimensions
• Ratio vs interval
• Fixed vs variable
Partial Reinforcement
– First correct response after a fixed time interval is
reinforced. Ex. Every 3 mins
– Reinforcement given after a fixed number of
responses. Ex. Every 3rd response
– Reinforcement given for first correct response after a
variable time interval, centered around an average.
Ex. On average 3 mins interval
– Reinforcement given after a variable number of
responses, centered around an average ex. 3
responses need for reinforcement
Escape and Avoidance
– Learn responses to terminate aversive stimuli
– Ex. Taking an Advil to relive a headache
– Learn responses to avoid aversive stimuli
– Ex. In winter dress warmly before going out into
the cold
Learning & Extinction
– More rapid learning
– Consequences easier to perceive
– Extinction more rapid
– Slower learning
– More resistant to extinction- especially on variable
schedule- due to unpredictability
Avoidance Learning
– Chock administers and rats run to the other side of
the box
– Negatively reinforced: escape removed shock
– Introduce warning light
– Conditions the light to be associated with shock which
leads to avoidance learning
– Hard to extinguish
• Two-factor theory of avoidance
• Light paired with shock (UCS), light becomes CS that elicits
fear CR
• Fleeing from light is negatively reinforced by termination of
fear
• strengthens & maintains avoidance response
Constraints on Operant Conditioning
• Instinctive drift
– Conditioned response ‘drifts back’ toward
instinctive behaviour
– Ex. Training a pigeon to peck for food is easy
because they biologically are primed to peck for
food
• Hard to train a pigeon to peck to escape a shock
because they would fly away to escape something
dangerous or unpleasant
Classical vs. Operant Conditioning
• Classical
– Behaviour changes due to association of two stimuli (CSUCS) presented prior to the response (CR)
– Focus on elicited behaviours- CR triggered involuntarily
• Operant
– Behaviour changes as a result of consequences that follow
it
– Focuses on emitting behaviours- that are under physical
control
• *Although both are different processes- many learning
situations involve both
Learning and the Brain
• No single part controls learning
• Nucleus accumbens & dopamine
– Involved in ability to experience reward
• Cerebellum
– Plays a role in acquiring some classical
conditioned behaviour. Ex. Eye blink response
• Amygdala
– Involved in acquiring classically conditioned fears
Modelling
• Bandura
• Bobo doll experiment
• Kids would watch a model behave aggressively
towards the doll
– Some models were rewarded & some
reprimanded & some no consequences
– Those who saw models punished had fewer
aggressive acts- but when given the incentive
could still perform them
Observational Learning
• 4 basic steps
1. Attention
2. Retention
3. Reproduction
4. Motivation (the key component)
Review Questions
1. Pavlov determined that a tone triggered salivation more quickly
when the size of the was more intense or greater.
A. unconditioned response
B. unconditioned stimulus
C. conditioned response
D. conditioned stimulus
2. Under which of the following conditioned stimulus-unconditioned
stimulus pairing conditions does learning usually occur most quickly?
A. forward trace pairing
B. forward short-delay pairing
C. simultaneous pairing
D. backward pairing
3. A man becomes moderately aroused whenever his wife wears a particular
red outfit. In terms of classical conditioning principles, the red outfit
represents a(n) that has become a(n) .
A. conditioned stimulus; unconditioned stimulus
B. previously neutral stimulus; conditioned stimulus
C. unconditioned stimulus; conditioned stimulus
D. unconditioned response; conditioned response
4. A young child is hungry and wants a cookie but is too short to reach the
table where the cookie jar is kept. She tries various things to get the jar, such
as jumping or throwing her teddy bear at the jar in hopes of knocking it off
the table, but to no avail. Eventually, almost by accident, she realizes that she
can pull the tablecloth on which the jar sits and is thus able to reach the jar. In
the future, she will be more likely to try this technique again since it was
effective. This example best demonstrates:
A. Thorndike's law of effect.
B. the principles of classical conditioning.
C. the concept of shaping.
D. the use of partial reinforcement.
5.Giving athletes random drug tests and police
officers setting up roadside speed traps are
examples of the:
A. fixed interval schedule.
B. fixed ratio schedule.
C. variable interval schedule.
D. variable ratio schedule.
For Shugar’s Class in Particular
Figures & tables you should really know
• Figures: 7.3, 7.4, 7.5, 7.6,
7.12, 7.15, 7.20, 7.27, 7.29
• Table 7.1
• What to do with them? explain them to a friend
 it really helps!
• For extra help go to this youtube channel (abudl
Rahman- psychology 101) for videos on classical
and operant conditioning and other psychological
concepts