Learning

  • Learning - a relatively permanent change in knowledge, attitude, or behavior brought on by experience. Not due to maturation.
  • Three Types of Learning:
    • Classical Conditioning Learning by association.
    • Operant Conditioning Learning by consequences of behavior
    • Obseravtional Learning Learning by modeling others

Classical Conditioning – 1 stimulus comes to predict the occurrence of another stimulus and elicits a response similar to related to response evoked by that stimulus

Classical Conditioning Terms

  • Unconditioned Stimulus (UCS or US)
    • Produces/elicits a response w/o previous or prior learning.
  • Unconditioned Response (UCR or UR)
    • Unlearned response (reflex) invariably elicited by the US
  • Conditioned Stimulus (CS)
    • Previously neutral stimulus that elicits a response after being paired with or associated with the US.
  • Conditioned Response (CR)
    • Learned response to CS after pairing of US-CS. Usually similar to the UR.

Other Important Terms

  • Acquisition
    • Forming US and CS link
  • Extinction
    • CS not followed by US. CR eventually ceases.
  • Spontaneous Recovery
    • After first extinction, CS presented at a later time (rest period). CR again occurs for a limited period of time in a weaker form.
  • Stimulus Generalization
    • Responds to stimuli similar to CS.
  • Stimulus Discrimination
    • Can distinguish between a new stimulus and the already learned stimulus. The new stimulus is similar to the old CS.
  • Higher Order Conditioning
    • Neutral stimulus paired with CS becomes associated with it, gains the power to elicit the same CR (Not the same as stimulus generalization)

Temporal Relationships between CS and UCS

  • Delayed - CS precedes the US and still there when US is presented (tone is presented and remains on while food is presented). Best for conditioning
  • Trace - CS presented first but ends before the US occurs (taste aversion)
  • Simultaneous - CS and US presented at the same time
  • Backward - CS follows the US (tone follows the food). Worst for conditioning

Application of Classical Conditioning:
Fears - The case of Little Albert Watson & Raynor (1920)

  • Can fears be acquired through classical conditioning.?
    • When Little Albert touched a white rat, Watson made a loud noise behind Albert’s head.
    • Albert began to cry
    • Soon, Albert showed fear of the rat.
  • His fear generalized to other, similar. objects: dog, rabbit, fur coat, Watson in beard.

Biological Constraints on Classical Conditioning

  • Can any association be learned? Humans more easily conditioned to fear stimuli harmful to well-being or related to survival through evolution (snakes, heights)
  • Conditioned taste aversion
  • CS
    • Sweet water, flash of light, clicking sound.
  • US
    • For first group, electric shock which produces pain.
      • RESULTS: Feared light & click, but not sweet water.
    • For second group, x-rays which cause nausea.
      • RESULTS: Feared sweet water, but not light & click. CTA

Other factors influencing classical conditioning

  • How reliably the CS predicts the US
  • Number of pairings
  • Intensity of the US

Operant Conditioning

  • Learning that occurs when an individual produces an active behavioral response which is followed by an environmental stimulus, which influences the likelihood that the response will be repeated again in the future. Consequences are manipulated to increase or decrease behavior in the future.

Types of Reinforcers

  • Primary reinforcers
    • Stimuli that have inherent value.
      • Food, water, warmth, sleep, sex
      • An unlearned reinforcement
  • Secondary reinforcer
    • Stimuli. that acquire reinforcement properties by being associated with primary reinforcer
      • Money, praise
      • A learned reinforcer

Reinforcement

  • Positive - When the behavior occurs, a pleasant event follows.
    • Get a cookie for being good, Get paid for going to work.
    • Reinforcers must increase behavior..
    • What is reinforcing for one person may not be reinforcing for another.
  • Negative - When the behavior occurs, an unpleasant event ends.
    • Not the same as punishment!
    • Negative reinforcement increases likelihood that a behavior will occur in future.
    • Two types - escape and avoidance
    • Escape - learns to make a response to end the aversive situation or event (Buckle seat belt to stop buzzing noise. Taking an aspirin to end headache.)
    • Avoidance - learns to respond to a stimulus that signals an impending unpleasant event, avoid conditions associated with dreaded or aversive outcomes (filling up the gas tank before you run out of gas, phobias).

Punishment

  • When the behavior occurs, an unpleasant or aversive event follows.
    • Punishment decreases the likelihood of the behavior occurring in future.
    • If behavior increases or doesn’t change, it wasn’t punishment!
  • Positive Punishment – application, some aversive occurs to decrease behavior – spanking, child misbehaves and gets yelled at
  • Negative Punishment – removal, something desirable is taken away to decrease behavior - being grounded, taking away a favorite toy, if you misbehave, I’ll turn off the TV

 

Punishment Issues

  • Often doesn’t extinguish the behavior – rather suppresses behavior when punishing agent present
  • Indicated behavior unacceptable, but doesn’t help develop more effect behavior – need to reinforce appropriate behavior
  • May cause negative feelings, aggression
  • Most effective when applied during misbehavior or immediately afterwards – interrupting behavior best since remove rewarding aspects
  • Must be applied consistently

Schedules of Reinforcement

  • Continuous
    • Reinforce every time behavior occurs
    • Improves initial learning., most effective way to condition new responses
    • Extinction occurs quickly when reinforcement stops.
  • Partial or Intermittent
    • Reinforce some, but not all, responses.
    • Better for the maintenance of behavior.
    • Resistant to extinction (partial reinforcement extinction effect).


Partial Reinforcement: Ratio Schedules

Fixed Ratio

  • Ratio: Based on number of responses.
  • Fixed: The number of responses before reinforcement doesn’t change.
    • I’ll pay you $30 for every car you wash.
  • Behavior.: High levels of response with pause after receiving reinforcement. Low resistance to extinction

·  Variable Ratio

  • Ratio: Based on number of response.
  • Variable: The number of responses needed before reinforcement changes.
    • Based on an average. Slot machines pay off after an average number of lever pulls.
  • Behavior: High levels of response. Resistant to extinction.

Partial Reinforcement: Interval Schedules

Fixed Interval

  • Interval: Delivery of reinforcement dependent on the passage of time.
  • A response is required.
  • Fixed: The period of time does not change.
    • Picking up your pay every Friday. Elections in the U.S.
  • Behavior: Lower levels of response. Scallop effect - increase responding as get closer to the time you will be reinforced. Low resistance to extinction

·  Variable Interval

  • Interval: Delivery of reinforcement dependent on the passage of time.
    • A response is required.
  • Variable: The per. of time changes.
    • Based on an average. Waiting for a bus.
  • Behavior: Lower levels of steady response. High resistance to extinction

Complex Behaviors

  • Shaping - Method of successive approximation.
    • Reinforcing behavior that are increasingly similar to desired behavior.
  • Chaining - Useful for teaching a series of behavior that fit together.
    • Reinforcing each behavior as it occurs, rather than reinforcing at the end of the sequence.
  • Superstitious Behavior - Assigning relationships between stimuli because of connections that are supposed to exist between them. Falsely believe connection between act and consequence
    • Pressing the elevator button many times to make the elevator show up faster

Learning is not same as performance

  • Latent Learning
    • Rat placed in maze without reinforcement. Shows little decrease in running times or number of errors.
    • The trial after the first reinforcement - rat greatly improves
    • Rat in group 1 reinforced for running the maze correctly, while the rat in group 2 never reinforced. Group 3 rat reinforced only on 11th run. Rat had learned the maze but not motivated to perform well until reinforced, demonstrating latent learning had occurred.


Observational Learning

  • Modeling
    • Learning occurs by observing others’ behaviors and the consequences of their behavior. (Vicarious learning)
  • Bandura’s early studies
    • Children watched a film of adults hitting & kicking a doll.
    • Adults were reinforced, punished, or no consequence for their behavior.
    • Children who saw the adults reinforced were more aggressive with the doll than the children who saw the other two versions of the film.
    • Condition of adult ignoring doll and playing with other toys. Also control group who didn’t see a model. Ignoring doll group less aggressive than any of the other groups (including control)

Process of Modeling

  • Attention - must pay attention to model’s behavior and the consequences of that behavior.
  • Retention - be able to recall what was observed.
  • Reproduction - motor ability to reproduce model’s behavior.
  • Motivation want to reproduce behavior. (vicarious reinforcement)