Classical (Pavlovian) Conditioning
What is Learning?
- Any relatively permanent change in the behavior, thoughts, and
feelings
of an organism that results from experience
- Reflexive response
- Adaptive for survival
- Experience as the key to learning
- Forming associations
- Simple animals can learn simple associations
- More complex animals can learn more complex associations
- It is important to survival to associate the past with the immediate
future
Types of Learning
- Classical (Pavlovian) conditioning
o Learning an association between two stimuli
- Operant conditioning.
o Learning to associate a response and its consequences
History
- Ivan Pavlov
- “Psychic reflexes”
- Experimental subjects were dogs restrained by harnesses in an
experimental
chamber
- Saliva collected
- Pavlov noticed that the dog would begin salivating at stimuli
associated
with food
- His research suggested that one stimuli or event could come to be
associated
with a subsequent event
Terminology
Unconditioned Stimulus (UCS)
· The stimulus that evokes an unconditioned response
without previous
conditioning
Unconditioned Response (UCR)
· The unlearned reaction to an unconditioned stimulus
that occurs
without previous conditioning
Conditioned Stimulus (CS)
· A previously neutral stimulus that has, through
conditioning,
acquired the capacity to evoke a conditioned response
Conditioned Response (CR)
· A learned reaction to a conditioned stimulus that
occurs because
of previous conditioning
o The unconditioned response and the conditioned response are
virtually
the same behavior
o The difference is in terms of what elicits the response
Trial
· The presentation of any stimulus or pair of stimuli
· Psychologists are interested in how many trials are required
to
establish a particular conditioned bond
Temporal Contiguity
- The interval between the CS and the US
- Defines the degree of association of the stimuli
Contingency
- The predictability of the occurrence of one stimulus from the
presence
of another
- Learning to predict an event based on cue
- The more predictable the association, the stronger the
conditioned response
- Conditioning works best when the CS and UCS have just the sort of
relationship
that would lead a scientist to conclude that the CS causes the UCS
Basic Processes
· Occurs in most types of animals
· Operates under the same principles across most species
· Results generalizable
- Rats and pigeons
Acquisition
· The formation of a newly acquired conditioned response
· An association between two events or two types of stimuli
· Potential to become CS
Extinction
· The gradually weakening and disappearance of a
conditioned response
tendency
· Occurs as a result of the continued presentation of the CS
without
the UCS
· Extinction occurs slowly for a strongly established bond
Spontaneous Recovery
· The reappearance of an extinguished response after a
period of
non-exposure to the CS
o Renewal effect
o Extinguished response suppressed
Stimulus Generalization
· Occurs when an organism has learned a response to a
specific stimulus
responds in the same way to new stimuli that are like the original
stimuli
Examples of Conditioned Responses
Positive Responses
- Pleasant associations
- Fetishes
Negative Responses
Anxiety
Phobias
- An irrational fear
- Focuses anxiety on some specific object, activity or situation
- Mary Cover Jones (1924)
Neuroses
- Experimental neurosis
– What at first seems like a clear choice becomes less and less clear,
leading to conflict on the part of the learner
Facilitated Learning
- Basic belief of Behaviorism
- Basic laws of learning essentially similar in all animals
- Any natural response could be conditioned to any neutral stimulus
- An animals capacity for conditioning is constrained by its biology
Rats and Sparkle Water
- John Garcia
o Testing hypothesis
· Sweetened water – radiation poisoning
· Sparkle water – radiation poisoning
· Sweetened water – shock
· Sparkle water – shock
o Results
· Sugar water
Paired with nausea
Paired with shock
· Sparkle water
Paired with nausea
Paired with shock
o Conclusions
· Animals are biologically predisposed to learn
associations
which would aid in their survival
Taste Aversion
- Humans appear biologically predisposed to develop taste
aversions
Phobias
- Humans appear biologically prepared to fear dangers faced by
our ancestors
- Most phobias focus on objects that present occasional threats
- It is easy to condition and hard to extinguish fears of such stimuli
Operant Conditioning
Classical conditioning
- Reflexive responses
- Stimuli precede response
Operant conditioning
- Voluntary responses
- Controlled by consequences following response
Founder
- B.F. Skinner
- Promoted return to a strict stimulus-response approach
- Mental events not proper domain of psychology
- Emphasized how environmental factors mold behavior
- Research directed at discovering principles governing human
behavior
- Fundamental principle of operant conditioning
Methodology
- Specific requirements
- Skinner box
- Two types
- Rats
- Pigeons
- Design
Study of Behavior
- Focus
- Contingencies of reinforcement
- Setting
- Stimulus discrimination
- Stimulus generalization
- Response
- Respondents
- A response that is unconditionally elicited by some
particular
stimulus
- Classically conditioned
- Operants
- A response that occurs for no observable reason
- Emitted not elicited
- Shaping
- Law of effect
- An animal is more likely to perform actions for
which it has just
been rewarded
- Gradual molding of diffuse behavior into a specific,
well-defined
operant
- Reinforcer
- Any event that increases the probability of the
operant upon which
it is contingent
- Positive reinforcement
- Reward
- Increases frequency of response
- Negative reinforcement
- Increases frequency of response
- Involves the removal of a (typically) noxious stimulus
- Spanish Inquisition Analogy
- Reinforcement versus Punishment
- Punishment
- Decreases frequency of a response
- Generally ineffective
- Suppresses behavior
- Can create unwanted emotional side effects
- Effective punishment
- Alternative responses
- Compliment with positive reinforcement
- State reason for punishment
- Immediate punishment
- Intensity appropriate
- Inescapable
- Penalties (removal of pleasant stimuli) rather than physical or
emotional pain
- Used in situations in which the desired alternative behavior
involves
escape
Schedules of Reinforcement
- Rate at which a response is reinforced
- Affects behavior
- Fixed ratio
- Reinforces behavior after a fixed number of responses
- After reinforcement
- Typically a pause in responding
- Variable ratio
- Responses are rewarded an average number of times
- Unpredictable
- Produces high, steady rates of responding
- Resistant to extinction
- Fixed interval
- Reinforces first appropriate response after a fixed
amount of time
- Few responses made until time draws near when reinforcement is
expected
- Behavior increases rapidly
- Variable interval
- Response is reinforced after a variable amount of time
has elapsed
- Behavior slow and consistent
Cognition in Learning
- Biological predisposition
- Constrain capacity for operant conditioning
- “Instinctive drift”
- Cognitive Maps
- Tolman
- Believed organisms selectively take in information
from the environment
- Cognitive map
- Experiment
- Condition 1
- Condition 2
- Condition 3
- 11th Day
- Condition 1
- Condtion 2
- Condition 3
- Results
- Latent learning
- Learning that becomes apparent only when there
is some incentive
to demonstrate it
- Condition 1
- Condition 2
- Condition 3
Observational Learning
- Vicarious learning
- Learning that occurs when we observe the
consequences of other
people’s behavior
- Involves both cognition and conditioning
- Direct Observation
- Children at drawing task
- Adult working on Tinkertoys
- Adult attacks a Bobo doll
- Child taken to a room with a lot of great toys
- Experimenter interrupts child’s play
- Takes frustrated child into another room containing a Bobo doll
- Results
- Indirect Observation
- Can learn by watching behaviors on television
- 14 month old boy in a lab
- Imitating behavior he has seen on TV
- Children as well as adults are just as likely to imitate
positive
as negative acts