ch4 reinforcement p2

Reinforcement Overview

I. Reinforcement in General

  • Basic Principle of Behavior

    • Established by B.F. Skinner in laboratory research and supported by over 40 years of human research.

    • A critical component of many behavior modification procedures.

II. Defining Reinforcement

  1. Occurrence of a Behavior

  2. Immediate Consequence: The behavior results immediately in a consequence.

  3. Strengthening of Behavior: The behavior is strengthened, indicating that in the future the behavior is more likely to occur.

  4. Temporal Aspect:

    • Present: Behavior is followed by a consequence.

    • Future: The behavior's likelihood of occurrence increases.

  5. Operant Behavior: Defined as behavior that is controlled by its consequences and is strengthened through the process of reinforcement.

III. Effects of Reinforcement on Behavior

  • Increase in Frequency: The behavior occurs more often.

  • Increase in Duration: The behavior lasts longer.

  • Increase in Intensity: The behavior becomes more vigorous.

  • Decrease in Latency: The time before the behavior occurs is reduced.

IV. Two Types of Reinforcement

  1. Positive Reinforcement: Involves the addition of a stimulus following a behavior which strengthens that behavior.

  2. Negative Reinforcement: Involves the removal of an aversive stimulus following a behavior which also strengthens that behavior.

  • Both forms of reinforcement make the behavior more likely to occur in the future.

II. Positive Reinforcement

  • Definition:

    • Behavior is followed by the presentation of a stimulus (reinforcer) which strengthens the behavior.

  • Positive Reinforcement/Reward Training:

    • A reinforcement procedure where a behavior is followed by the introduction of a stimulus or an increase in the intensity of that stimulus.

III. Unintentional Reinforcement Examples

  1. Temper Tantrums: A child has a tantrum and might be unintentionally reinforced by receiving attention or a desired item.

  2. Dog Jumping Up: A dog that jumps on visitors may receive affection, reinforcing the behavior.

  3. Classroom Behavior: Students who call out answers without raising hands may be reinforced by the teacher's acknowledgment.

IV. Negative Reinforcement

  • Definition:

    • Behavior is followed by the removal of an aversive stimulus, strengthening the behavior.

  • Two Types:

    • Escape: The behavior leads to the cessation of an aversive stimulus.

    • Avoidance: The behavior prevents the aversive stimulus from occurring.

  • Negative Reinforcement/Escape Training: A reinforcement method where behavior removal or decrease in the intensity of an aversive stimulus follows the behavior.

  • Negative Reinforcer: A stimulus that when removed after a behavior increases or maintains the strength of that behavior.

V. Positive and Negative Reinforcement in the Same Situation

  • Example: In a grocery store, a child's tantrum may lead to receiving candy (positive reinforcement), while the parent's behavior of giving candy is reinforced by the removal of the child's tantrum (negative reinforcement).

VI. Determining Type of Reinforcement

  1. Identify the behavior.

  2. Analyze what happened immediately after the behavior: Was a stimulus added (positive reinforcement) or removed (negative reinforcement)?

  3. Investigate the future behavior: Did the behavior strengthen? Was it more likely to occur?

Test Yourself: Positive/Negative Reinforcement or Neither?

  1. Sam’s mom nagging: Stops nagging when Sam cleans his room - Positive Reinforcement.

  2. Jim with hangover: Experiences hangover leading Jim to drink less - Negative Reinforcement.

  3. Linus praises brother: Brother takes out trash after praise - Positive Reinforcement.

  4. Jack and umbrella: Keeps umbrella to avoid getting wet - Negative Reinforcement.

  5. Cash and hangover: Similar to Jim - Negative Reinforcement.

  6. Sam’s sister cleaning: Similar situation as Sam - Positive Reinforcement.

Quick Reference: Type of Reinforcement

  1. Positive Reinforcement: Adding a favorable consequence to increase a behavior (e.g., receiving a cookie for eating vegetables).

  2. Negative Reinforcement: Removing an unfavorable consequence to increase a behavior (e.g., lowering insurance rates for safe driving).

IV. Primary and Secondary Reinforcers

Definitions:

  • Primary Reinforcers: Do not depend on another reinforcer for their reinforcing properties (e.g., food, water, sexual stimulation).

  • Secondary Reinforcers: Acquire reinforcing properties through association with other reinforcers (e.g., money, praise).

  • Generalized Reinforcers: Secondary reinforcers associated with multiple different reinforcers (e.g., money).

Secondary (Conditioned) Stimuli

  • Definition: Previously neutral stimulus that becomes a reinforcer through pairing with an established reinforcer.

  • Examples:

    • Family members' smiles, praise, attention.

    • Material items such as toys, grades, and positive evaluations.

V. Factors that Influence Reinforcement

  • Immediacy (Contiguity): The closeness of events in time or space.

  • Consistency (Contingency): Dependency between events; reinforcement can be stimulus-contingent or response-contingent.

  • Reinforcer Characteristics: Attributes of the reinforcer that may affect its efficacy.

  • Task Characteristics: Features of the task that can influence reinforcement efficacy.

  • Deprivation Level: The level of need for the reinforcer can impact its effectiveness.

VI. Schedules of Reinforcement

  • Schedule of Reinforcement: A rule defining how reinforcers are delivered following behavior.

  • Schedule Effects: Distinctive rates and patterns of responding associated with specific reinforcement schedules.

Types of Schedules:

  1. Continuous Reinforcement Schedule: A behavior is reinforced every time it occurs.

  2. Intermittent/Partial Reinforcement Schedule: Behavior is only reinforced sometimes, contrary to the continuous schedule.

Continuous vs Intermittent Reinforcement

  • Continuous reinforcement produces faster learning while intermittent reinforcement leads to slower learning but greater resistance to extinction.

Specific Schedule Types

Fixed Ratio Schedules

  • Definition: Reinforcer is delivered after a fixed number of responses; the number remains constant.

  • Characteristics:

    • High response rate with post-reinforcement pause.

    • Example: Piece rate pay in job settings.

Fixed Ratio Schedule (FR)

  • Example: Rat receives food after every 3rd lever press (FR3 = 3:1).

  • Post-Reinforcement Pause: A brief pause in responding following reinforcement, particularly related to FR and Fixed Interval (FI) schedules.

  • Run Rate: The rate behavior resumes following reinforcement.

Variable Ratio Schedule

  • Definition: Reinforcer is provided after a variable number of responses, based on average rates.

  • Characteristics:

    • High response rates with no post-reinforcement pause.

    • Example: Gambling on a slot machine or telemarketing.

Fixed Interval Schedule

  • Definition: Reinforcer is provided for the first response after a fixed time interval; the interval does not change.

  • Characteristics:

    • Low, steady rates of responses increase towards the end of the interval.

  • Examples: Mail delivery every 2 hours, hourly worker supervision checks.

Fixed Interval Schedule (FI)

  • Example: A pigeon is reinforced for the first peck after 5 seconds (FI5).

Variable Interval Schedule

  • Definition: Reinforcer is provided for the first response after variable time intervals on average.

  • Characteristics:

    • Low but steady rate of behavior.

  • Example: Unpredictable checks by a supervisor or waiting for a deer when hunting.

Test Yourself on Reinforcement Schedules

  • Examples:

    1. Rat gets food every 3rd lever press (Fixed Ratio).

    2. Paid weekly regardless of work (Fixed Interval).

    3. Paid for every ten boxes produced (Fixed Ratio).

    4. Occasional jackpot on a slot machine (Variable Ratio).

    5. Checking cell phone for texts throughout the day (Variable Interval).

    6. Child’s tantrum leading to concessions from parents (Variable Ratio).

Quick Reference: Schedules of Reinforcement

  • Ratio:

    • Fixed: Reward after certain number of behaviors (e.g., bonus for every 5 cars sold).

    • Variable: Reward after random number of behaviors (e.g., slot machines).

  • Interval:

    • Fixed: Reward after a specific amount of time (e.g., paycheck every two weeks).

    • Variable: Reward after a random amount of time (e.g., receiving a text message).

Conclusion on Reinforcement Schedules

  • Best Schedule:

    • Ratio schedules produce the fastest behavior changes.

    • Interval schedules yield slower training but are harder to extinguish.

    • Fixed schedules lead to quicker training than variable schedules, yet variable schedules exhibit greater resistance to extinction.