Basic Principles of Reinforcement

Basic Principles of Reinforcement

Definition of Reinforcement

  • Reinforcement is a crucial behavioral process for modifying behavior.
  • It involves a behavior being followed by a consequence.
  • This consequence strengthens the behavior, making it more likely to occur in the future.
  • Example: A teen does chores and receives an allowance. If the chore-doing behavior increases because of the allowance, reinforcement has occurred.

Components of Reinforcement

  • Reinforcement is a process.
  • It has an effect on behavior, specifically strengthening it.
  • Operant behavior is influenced by antecedents and consequences.
  • Consequences either strengthen or weaken behavior.
  • Reinforcement strengthens behavior.

Three-Term Contingency (A-B-C)

  • A: Antecedent (what comes before the behavior).
  • B: Behavior or Response.
  • C: Consequence (what follows the behavior).
  • Focus is on the behavior and the consequence to understand reinforcement.
Examples:
  • Dog Whining:
    • Behavior: Dog whines.
    • Consequence: Owner provides food.
    • If whining increases, reinforcement has occurred.
  • Guitar Playing:
    • Behavior: Bill plays guitar.
    • Consequence: Audience claps and cheers.
    • If guitar playing increases, reinforcement has occurred.
  • Child Crying:
    • Behavior: Child cries.
    • Consequence: Father gives a doll.
    • If crying increases, reinforcement has occurred.

Types of Reinforcement

  • Two types based on adding or removing stimuli after a behavior.
  • Reinforcement always strengthens behavior.
Positive Reinforcement
  • A behavior is followed by the addition of a stimulus.
  • This strengthens the behavior.
  • Example: Child cries, father gives a doll. The doll being given is positive reinforcement if crying increases.
  • Example: Student completes work quickly, teacher praises. Praise is positive reinforcement if working quickly increases.
  • Pleasurable stimuli are added as a consequence.
Negative Reinforcement
  • A behavior is followed by the removal of a stimulus.
  • This strengthens the behavior.
  • Important: Negative reinforcement is NOT punishment. Punishment weakens behavior.
  • Example: Loud radio in the car. Turning the knob removes the loud music. If knob-turning increases, negative reinforcement has occurred.
  • Example: Shutting a window to stop cold air. Removing the cold air increases window-shutting behavior.
  • Unpleasant stimuli are removed.
Summary of Differences
  • Positive Reinforcement: Strengthens behavior by adding a pleasant stimulus.
  • Negative Reinforcement: Strengthens behavior by removing an unpleasant stimulus.
  • The effect on behavior (strengthening) determines the type of reinforcement.

Extinction

  • A reinforcer is no longer provided after a response.
  • Behaviors that were previously reinforced are no longer reinforced.
  • Extinction causes responses to decrease over time.
  • Example: A child who received candy for greeting his teacher stops receiving candy. The greeting behavior will decrease.
  • When teaching new skills, schedules are thinned gradually to maintain the skill without constant reinforcement.
Extinction Burst
  • Behavior may increase temporarily before decreasing when reinforcement is removed.
  • Example: Child pulls hair and is picked up. If picking up stops, hair pulling might increase before decreasing.

Types of Reinforcers

Primary Reinforcers (Unconditioned)
  • Function as reinforcers without prior learning.
  • Essential for biological functioning or survival.
  • Examples: food, water, warmth, sexual stimulation.
Secondary Reinforcers (Conditioned)
  • Acquire reinforcing properties by being paired with primary reinforcers or other secondary reinforcers.
  • Examples: toys, games, praise, social interaction, money.
Token Economies
  • Use tokens that are earned and exchanged for backup reinforcers.
  • Backup reinforcers are primary or secondary reinforcers chosen by the client.
  • Tokens themselves have no intrinsic value.
  • Tokens act as positive reinforcement.
Example:
  • Giving tokens for desired behaviors, like saying "juice," standing up, jumping, and sitting down. Tokens are then exchanged for shoes.
Benefits of Token Systems
  • Increase time between target behavior and backup reinforcement.
  • Provide reinforcement without interrupting instruction.
  • Less subject to satiation.
Token Boards
  • Tokens are placed on the board for target behaviors.
  • When the board is full, the client receives the backup reinforcer.

Factors Influencing Reinforcement Effectiveness

Immediacy
  • Time between behavior and reinforcer presentation.
  • Short time = higher probability of strengthening behavior.
  • Long time = lower probability of strengthening behavior.
  • Example: Dolphin gets a fish immediately after retrieving a ring vs. 30 minutes later.
Contingency
  • Rule about when a behavior will be reinforced.
  • Reinforce only desired behaviors; do not reinforce incorrect behaviors.
  • Example: Praise children for bringing plates to the sink but not for leaving them on the table.
Quality
  • Preference for the reinforcing stimulus.
  • Example: Chocolate ice cream is a better reinforcer than vanilla if the child prefers chocolate.
Magnitude
  • Size or duration of the reinforcer.
  • Example: 15 minutes of TV is more effective than 5 minutes.
Effort
  • Response effort required to obtain reinforcement.
  • Too much effort can prevent the behavior from occurring.
  • Example: Choosing a restaurant that is a 5 min walk compared to 20 min subway ride and 10 min walk.
  • Example: Reducing required social behaviors from 5 to 1 to get access to the iPad.
History of Reinforcement
  • Consider what has worked in the past for the individual.
  • Example: Salty snacks might work for some but not others. Social interaction may work for some but not others.
Motivating Operations (MOs)
  • Events that temporarily alter the effectiveness of a reinforcer.
  • Can make a reinforcer more or less effective.
Satiation
  • Repeated use of a reinforcer reduces its effectiveness.
  • Example: Eating a big meal reduces the reinforcing value of more food.
Deprivation
  • Lack of access to a reinforcer increases its effectiveness.
  • Example: Hunger increases the reinforcing value of food.

Schedules of Reinforcement

  • Rule specifying which occurrences of a behavior will be reinforced.
  • Continuum from no reinforcement (extinction) to reinforcing every response (continuous reinforcement).
  • Partial or intermittent reinforcement lies in between the two extremes.
Continuous Reinforcement
  • Used when teaching new skills.
  • Each correct response is reinforced.
Intermittent Reinforcement
  • Some, but not all, responses are reinforced.
  • Used as the response becomes more regular.
  • Example: Reinforcing every correct response initially, then reinforcing after a few correct responses in a row.
Thinning Schedules
  • Gradually reinforcing responses less often.
  • Important because:
    • Reinforcement in the natural environment is less frequent.
    • Intermittent schedules are more resistant to extinction.

Types of Intermittent Schedules

Ratio Schedules
  • Response-based: Reinforcer is delivered after a specific number of responses.
  • Example: Tom gets paid $120 for every 6 pages of translation.
Fixed Ratio (FR)
  • Reinforcer occurs after a fixed number of responses.
  • Example: Tom’s typing is on an FR6 schedule (paid after every 6 pages).
Variable Ratio (VR)
  • Reinforcer occurs after a variable number of responses (average).
  • Example: Jane's car starts after an average of 3 key turns (VR3).
Interval Schedules
  • Time-based: Require a time period to pass between reinforcers.
  • Reinforcer delivered for the first response after the interval ends.
  • Example: Teaching a child to string beads. At a fixed interval of 20 seconds, the first bead strung is reinforced.
Fixed Interval (FI)
  • Reinforcer delivered for the first response after a fixed time interval.
  • Example: Bead stringing on an FI 20-second schedule.
Variable Interval (VI)
  • Reinforcer delivered for the first response after a variable time interval (average).
  • Example: Teacher gives reward sticker after an average of 4 minutes (VI 4 minutes).

Schedule Thinning (Detailed)

  • Gradually moving from continuous to intermittent reinforcement.
Thinning Ratio Schedules
  • Gradually increase the number of responses before reinforcement.
  • Increase the response ratio in small increments.
  • Too quick schedule thinning will result to the learner giving up.
  • Example: Moving from FR1 to VR3 for saying “hi.”
Thinning Interval Schedules
  • Gradually increase the time interval before reinforcement.
  • Increase the time interval in small increments.
  • Too quick schedule thinning will result to the learner giving up.
  • Example: Moving from FI 1 minute to VI 2 minutes for toy play.

Review

  • Reinforcement strengthens behavior.
  • Positive and negative reinforcement.
  • Conditioned and unconditioned reinforcers.
  • Factors influencing reinforcement effectiveness.
  • Schedules of reinforcement should be thinned gradually.