Schedules and Theories of Reinforcement
Schedules of Reinforcement
- Definition: A schedule of reinforcement outlines the response requirement that must be met to obtain a reinforcer.
- Example: How many times must a rat press a lever to receive a food pellet?
- Steady-state behaviors: These are stable response patterns that develop after significant exposure to a reinforcement schedule.
- Different schedules lead to distinct response patterns.
Types of Reinforcement Schedules
Continuous vs. Intermittent Reinforcement
Continuous Reinforcement Schedule (CRF):
- Each specified response is reinforced.
- Best for strengthening newly learned behaviors.
Intermittent (Partial) Reinforcement Schedule:
- Only some responses are reinforced.
- Promotes persistence among learners.
Fixed Ratio (FR)
- Definition: Reinforcement is contingent on a fixed number of responses.
- Example: FR 5 - A rat must press the lever 5 times to obtain a food pellet.
- Light (SD): Lever press leads to FR 5 (Response) → Food (Reinforcer).
- Produces a high response rate with a post-reinforcement pause (a break after receiving reinforcement).
Variable Ratio (VR)
- Definition: Reinforcement occurs after a varying, unpredictable number of responses.
- Example: VR 50 - Requirement may vary between 1 to 100 responses, with the average being 50 responses.
- Generally results in a high rate of response with little to no post-reinforcement pause.
Fixed Interval (FI)
- Definition: Reinforcement is contingent upon the first response after a fixed, predictable period of time.
- Example: FI 30-sec - The first response after 30 seconds earns a reinforcer.
Variable Interval (VI)
- Definition: Reinforcement is contingent upon the first response after a varying, unpredictable time period.
- Example: VI 60-sec - Time period might range from 1 to 120 seconds, averaging 60 seconds.
Response Patterns and Schedules
| Schedule Type | Response Rate | Post-reinforcement Pause |
|---|---|---|
| Fixed Ratio (FR) | High | Yes |
| Variable Ratio (VR) | High | No |
| Fixed Interval (FI) | Increasing Moderate | Yes |
| Variable Interval (VI) | Moderate | No |
Duration Schedules
- Fixed Duration (FD): Behavior must be performed continuously for a fixed, predictable period.
- Variable Duration (VD): Behavior must be performed continuously for a varying, unpredictable period.
Response-Rate Schedules
Differential Reinforcement of High Rates (DRH):
- Reinforcement is contingent upon emitting a certain number of responses in a designated time.
- Rewards high response rates.
Differential Reinforcement of Low Rates (DRL):
- Reinforcer is only delivered after a minimum amount of time passes between responses.
- Encourages slower response rates.
Differential Reinforcement of Paced Responding (DRP):
- Contingent on emitting responses at a steady rate, not too fast or too slow.
Noncontingent Schedules
- Definition: Reinforcers are delivered independently of any specific response.
- Fixed Time (FT) schedule: Reinforcer is delivered after a fixed, predictable period, regardless of behavior.
- Variable Time (VT) schedule: Reinforcer is delivered after varying, unpredictable periods, regardless of behavior.
- VT schedules can lead to superstitious behaviors due to their unpredictable nature.