Learning Flashcards
Learning
A relatively durable change in behaviour or knowledge that is due to experience.
Habituation
Tendency to discontinue responding repeatedly occurring uninformative events. Simplest form of learning.
Releases us from distraction from events that are uncorrelated with consequences. Nervous system is tuned to responding to significant changes in the environment.
Pavlov
Studied the digestive processes of dogs and observed “psychic reflexes”.
Classical Conditioning
A stimulus acquires the capacity to evoke a response that was originally evoked by another stimulus.
Respondent or Pavlovian conditioning.
Stimulus-stimulus learning.
Appropriate responses may occur faster and more effectively with advance warning.
Previously unimportant stimuli take on symbolic value.
Unconditioned Stimulus (US)
Upon presentation evokes a response called the unconditioned response (UR).
food —> salivation
Neutral Stimulus NS
Paired continuously with the US
bell + food —> salivation.
Initially the NS evokes no response when presented on its own.
Eventually the neutral stimulus becomes a conditioned stimulus (CS) once it produces the conditioned response (CR)
Conditioning is said to occur when CR appears before US onset.
Acquisition
Learning phase
Intense US —> more rapid learning
Acquisition
Forward, delay conditioning
Most efficient conditioning
Extinction
CS alone and CR declines
Gradual weakening of the CR tendency
Spontaneous recovery
After period of delay CS –> CR
Less intense, return to baseline faster
Generalization
Similar CSs produce the same CR
Stimuli closer to the CS produce a higher probability of a CR (generalization gradient)
Strength of CR (down) as similarity of the stimulus (down)
Discrimination
Trained to learn that CS+ predicts US but CS- does not.
CS must occur prior to US.
Conditioned Emotional Response
quite prevalent in humans.
Classically conditioned and extremely resistant to extinction
Fetishes
Sexual attachment
Conditioned Fear response
Phobias: unreasonable fear
Operant Conditioning
Responses come to be controlled by their consequences. Instrumental learning.
Thorndike pioneered instrumental conditioning. Wanted to determine if animal could think.
Law of effect
If a response in the presence of a stimulus leads to satisfying effects, the association between the stimulus and response is strengthened.
Discriminative Stimulus
Sets the occasion for a response
Operant behaviour
Response
Consequence
Contingency of behaviour
3-term contigency
Discriminiative stimulus,
operant behaviour, consequence.
Consequences of S-R relationships determine behaviour. Appetitive stimuli presented or removed.
Aversive stimuli presented or removed.
Law of effect was replaced by the notion of reinforcement.
Reinforcement
Occurs when an even following a response increases an organism’s tendency to make the same response in the presence of the stimulus in the future.
Punishment
Occurs when an event following a response decreases an organism’s tendency to make the same response in the presence of the stimulus in the future.
Positive Renforcement
Discriminative stimulus increases frequency of behaviour: presentation of an appetitive stimulus or positive reinforcer.
Negative Reinforcement
Discriminative stimulus increases frequency of behaviour: removal of an aversive stimulus or negative reinforcer.
Positive punishment
Discriminative stimulus decreases frequency of behaviour: presentation of an aversive stimulus or punisher
Negative punishment or response cost
Discriminative stimulus decreases frequency of behaviour: removal of an appetitive stimulus
Shaping (Acquisition)
The reinforcement of closer and closer approximation of a desired response
Extinction
Behaviour decreases because the reinforcer or behavioural contingency is removed.
Brief surge of increased responding.
Resistance to extinction occurs when responses persist without reinforcement.
Generalisation and discrimination
occur with respect to the discriminative stimulus
Primary reinforcers and punishers
Biological needs (food, pain, fear)
Conditioned reinforcers and punishers
Become associated with primary needs (money, flashing light of police car).
Mechanism of association is classical conditioning.
Schedules of Reinforcement
Continuous
After every response
Schedules of Reinforcement
Intermittent
Responses only reinforced some of the time
Interval - reinforcement based on intervals of time
Ratio - reinforcement provided after a certain number of responses.
Fixed Ratio
Reinforcement after a fixed number of non-reinforced trials (FR-10, after every 10 responses, FR-1 is continuous)
High rate of responding, pause after reinforcement, low resistance to extinction
Variable Ratio
Reinforcement unpredictable but on average occurs after some number of non-reinforced trials (VR-10, on average reinforcement once every 10 trials).
High rate of responding, no pause after reinforcement, high resistance to extinction
Fixed Intervals
Reinforcement occurs for the first response that occurs after a fixed time interval has elapsed (FI-10, after every 10 minutes).
Gradually increasing moderate rate, pause, low resistance to extinction.
Variable Interval
Reinforcement occurs for the first response that occurs after an unpredictable time interval which varies around a predetermined average (VI-10, unpredictable but on average after every 10 minutes).
Steady moderate rate, no pause, high resistance to extinction.
Escape Learning
Response that decreases or ends aversive stimulation
Avoidance Learning
Response that prevents aversive stimulation from occurring.
Conditioned flavor-aversion learning
Association of a substance’s flavour with illness
Blocking
A stimulus paired with a US fails to become a CS because it is redundant with an established CS. Conditioning is active and animal ignores redundant information.
Evidence for S-S interpretation of classical conditioning.
Connection between CS and mental representation of US
Observational Learning
Organism’s responding is influenced by the observation of others referred to as models. Both classical and operant conditioning.
