Schedules of reinforcement can affect the results of operant conditioning, which is frequently used in everyday life such as in the classroom and in parenting. Let’s examine the common types of schedule and their applications.
Table of Contents
Slot machines pay out according to which type of reinforcement schedule? A)variable ratio B)fixed-ratio C)fixed-interval D)variable interval. Know it is possible that the very next customer will buy a car.Sam's sales behavior is reinforced according to which type of reinforcement schedule? A)variable ratio B)fixed-ratio C)fixed-interval D.
Schedules Of Reinforcement
Operant conditioning is the procedure of learning through association to increase or decrease voluntary behavior using reinforcement or punishment.
Schedules of reinforcement are the rules that control the timing and frequency of reinforcer delivery to increase the likelihood a target behavior will happen again, strengthen or continue.
A schedule of reinforcement is a contingency schedule. The reinforcers are only applied when the target behavior has occurred, and therefore, the reinforcement is contingent on the desired behavior1.
There are two main categories of schedules: intermittent and non-intermittent.
Non-intermittent schedules apply reinforcement, or no reinforcement at all, after each correct response while intermittent schedules apply reinforcers after some, but not all, correct responses.
Non-intermittent Schedules of Reinforcement
Two types of non-intermittent schedules are Continuous Reinforcement Schedule and Extinction.
Continuous Reinforcement
A continuous reinforcement schedule (CRF) presents the reinforcer after every performance of the desired behavior. This schedule reinforces target behavior every single time it occurs, and is the quickest in teaching a new behavior.
Continuous Reinforcement Examples
e.g. Continuous schedules of reinforcement are often used in animal training. The trainer rewards the dog to teach it new tricks. When the dog does a new trick correctly, its behavior is reinforced every time by a treat (positive reinforcement).
e.g. A continuous schedule also works well with very young children teaching them simple behaviors such as potty training. Toddlers are given candies whenever they use the potty. Their behavior is reinforced every time they succeed and receive rewards.
Partial Schedules of Reinforcement (Intermittent)
Once a new behavior is learned, trainers often turn to another type of schedule – partial or intermittent reinforcement schedule – to strengthen the new behavior.
A partial or intermittent reinforcement schedule rewards desired behaviors occasionally, but not every single time.
Behavior intermittently reinforced by a partial schedule is usually stronger. It is more resistant to extinction (more on this later). Therefore, after a new behavior is learned using a continuous schedule, an intermittent schedule is often applied to maintain or strengthen it.
Many different types of intermittent schedules are possible. The four major types of intermittent schedules commonly used are based on two different dimensions – time elapsed (interval) or the number of responses made (ratio). Each dimension can be categorized into either fixed or variable.
The four resulting intermittent reinforcement schedules are:
- Fixed interval schedule (FI)
- Fixed ratio schedule (FR)
- Variable interval schedule (VI)
- Variable ratio schedule (VR)
Fixed Interval Schedule
Interval schedules reinforce targeted behavior after a certain amount of time has passed since the previous reinforcement.
A fixed interval schedule delivers a reward when a set amount of time has elapsed. This schedule usually trains subjects, person, animal or organism, to time the interval, slow down the response rate right after a reinforcement and then quickly increase towards the end of the interval.
A “scalloping” pattern of break-run behavior is the characteristic of this type of reinforcement schedule. The subject pauses every time after the reinforcement is delivered and then behavior occurs at a faster rate as the next reinforcement approaches2.
Fixed Interval Example
College students studying for final exams is an example of the Fixed Interval schedule.
Most universities schedule fixed interval in between final exams.
Many students whose grades depend entirely on the exam performance don’t study much at the beginning of the semester, but they cram when it’s almost exam time.
Here, studying is the targeted behavior and the exam result is the reinforcement given after the final exam at the end of the semester.
Because an exam only occurs at fixed intervals, usually at the end of a semester, many students do not pay attention to studying during the semester until the exam time comes.
Variable Interval Schedule (VI)
A variable interval schedule delivers the reinforcer after a variable amount of time interval has passed since the previous reinforcement.
This schedule usually generates a steady rate of performance due to the uncertainty about the time of the next reward and is thought to be habit-forming3.
Variable Interval Example
Students whose grades depend on the performance of pop quizzes throughout the semester study regularly instead of cramming at the end.
Students know the teacher will give pop quizzes throughout the year, but they cannot determine when it occurs.
Without knowing the specific schedule, the student studies regularly throughout the entire time instead of postponing studying until the last minute.
Variable interval schedules are more effective than fixed interval schedules of reinforcement in teaching and reinforcing behavior that needs to be performed at a steady rate4.
Fixed Ratio Schedule (FR)
A fixed ratio schedule delivers reinforcement after a certain number of responses are delivered.
Fixed ratio schedules produce high rates of response until a reward is received, which is then followed by a pause in the behavior.
Fixed Ratio Example
A toymaker produces toys and the store only buys toys in batches of 5. When the maker produces toys at a high rate, he makes more money.
In this case, toys are only required when all five have been made. The toy-making is rewarded and reinforced when five are delivered.
People who follow such a fixed ratio schedule usually take a break after they are rewarded and then the cycle of fast-production begins again.
Variable Ratio Schedule (VR)
Variable ratio schedules deliver reinforcement after a variable number of responses are made.
This schedule produces high and steady response rates.
Variable Ratio Example
Gambling at a slot machine or lottery games is a classic example of a variable ratio reinforcement schedule5.
Gambling rewards unpredictably. Each winning requires a different number of lever pulls. Gamblers keep pulling the lever many times in hopes of winning. Therefore, for some people, gambling is not only habit-forming but is also very addictive and hard to stop6.
What Type Of Reinforcement Is A Slot Machine
Extinction
An extinction schedule (Ext) is a special type of non-intermittent reinforcement schedule, in which the reinforcer is discontinued leading to a progressive decline in the occurrence of the previously reinforced response.
How fast complete extinction happens depends partially on the reinforcement schedules used in the initial learning process.
Among the different types of reinforcement schedules, the variable-ratio schedule (VR) is the most resistant to extinction whereas the continuous schedule is the least7.
Schedules of Reinforcement in Parenting
What Type Of Reinforcement Is A Slot Machine Invented
Many parents use various types of reinforcement to teach new behavior, strengthen desired behavior or reduce undesired behavior.
A continuous schedule of reinforcement is often the best in teaching a new behavior. Once the response has been learned, intermittent reinforcement can be used to strengthen the learning.
Reinforcement Schedules Example
Let’s go back to the potty-training example.
When parents first introduce the concept of potty training, they may give the toddler a candy whenever they use the potty successfully. That is a continuous schedule.
After the child has been using the potty consistently for a few days, the parents would transition to only reward the behavior intermittently using variable reinforcement schedules.
Sometimes, parents may unknowingly reinforce undesired behavior.
Because such reinforcement is unintended, it is often delivered inconsistently. The inconsistency serves as a type of variable reinforcement schedule, leading to a learned behavior that is hard to stop even after the parents have stopped applying the reinforcement.
Variable Ratio Example in Parenting
When a toddler throws a tantrum in the store, parents usually refuse to give in. But once in a while, if they’re tired or in a hurry, they may decide to buy the candy, believing they will do it just that one time.
But from the child’s perspective, such concession is a reinforcer that encourages tantrum-throwing. Because the reinforcement (candy buying) is delivered at a variable schedule, the toddler ends up throwing fit regularly for the next give-in.
This is one reason why consistency is important in disciplining children.
Related: Discipline And Punishment
References
- Case DA, Fantino E. THE DELAY-REDUCTION HYPOTHESIS OF CONDITIONED REINFORCEMENT AND PUNISHMENT: OBSERVING BEHAVIOR. Journal of the Experimental Analysis of Behavior. Published online January 1981:93-108. doi:10.1901/jeab.1981.35-93
- Dews PB. Studies on responding under fixed-interval schedules of reinforcement: II. The scalloped pattern of the cumulative record. J Exp Anal Behav. Published online January 1978:67-75. doi:10.1901/jeab.1978.29-67
- DeRusso AL. Instrumental uncertainty as a determinant of behavior under interval schedules of reinforcement. Front Integr Neurosci. Published online 2010. doi:10.3389/fnint.2010.00017
- Schoenfeld W, Cumming W, Hearst E. ON THE CLASSIFICATION OF REINFORCEMENT SCHEDULES. Proc Natl Acad Sci U S A. 1956;42(8):563-570. https://www.ncbi.nlm.nih.gov/pubmed/16589906
- Dixon MR, Hayes LJ, Aban IB. Examining the Roles of Rule Following, Reinforcement, and Preexperimental Histories on Risk-Taking Behavior. Psychol Rec. Published online October 2000:687-704. doi:10.1007/bf03395378
- Redish AD, Jensen S, Johnson A, Kurth-Nelson Z. Reconciling reinforcement learning models with behavioral extinction and renewal: Implications for addiction, relapse, and problem gambling. Psychological Review. Published online July 2007:784-805. doi:10.1037/0033-295x.114.3.784
- Azrin NH, Lindsley OR. The reinforcement of cooperation between children. The Journal of Abnormal and Social Psychology. Published online 1956:100-102. doi:10.1037/h0042490
Learning Objectives
- Distinguish between reinforcement schedules
Remember, the best way to teach a person or animal a behavior is to use positive reinforcement. For example, Skinner used positive reinforcement to teach rats to press a lever in a Skinner box. At first, the rat might randomly hit the lever while exploring the box, and out would come a pellet of food. After eating the pellet, what do you think the hungry rat did next? It hit the lever again, and received another pellet of food. Each time the rat hit the lever, a pellet of food came out. When an organism receives a reinforcer each time it displays a behavior, it is called continuous reinforcement. This reinforcement schedule is the quickest way to teach someone a behavior, and it is especially effective in training a new behavior. Let’s look back at the dog that was learning to sit earlier in the module. Now, each time he sits, you give him a treat. Timing is important here: you will be most successful if you present the reinforcer immediately after he sits, so that he can make an association between the target behavior (sitting) and the consequence (getting a treat).
Once a behavior is trained, researchers and trainers often turn to another type of reinforcement schedule—partial reinforcement. In partial reinforcement, also referred to as intermittent reinforcement, the person or animal does not get reinforced every time they perform the desired behavior. There are several different types of partial reinforcement schedules (Table 1). These schedules are described as either fixed or variable, and as either interval or ratio.What Type Of Partial Reinforcement Is Winning At A Slot Machine An Example Of
Fixed refers to the number of responses between reinforcements, or the amount of time between reinforcements, which is set and unchanging. Variable refers to the number of responses or amount of time between reinforcements, which varies or changes. Interval means the schedule is based on the time between reinforcements, and ratio means the schedule is based on the number of responses between reinforcements.What Type Of Reinforcement Is A Slot Machine Made
| Reinforcement Schedule | Description | Result | Example |
|---|---|---|---|
| Fixed interval | Reinforcement is delivered at predictable time intervals (e.g., after 5, 10, 15, and 20 minutes). | Moderate response rate with significant pauses after reinforcement | Hospital patient uses patient-controlled, doctor-timed pain relief |
| Variable interval | Reinforcement is delivered at unpredictable time intervals (e.g., after 5, 7, 10, and 20 minutes). | Moderate yet steady response rate | Checking Facebook |
| Fixed ratio | Reinforcement is delivered after a predictable number of responses (e.g., after 2, 4, 6, and 8 responses). | High response rate with pauses after reinforcement | Piecework—factory worker getting paid for every x number of items manufactured |
| Variable ratio | Reinforcement is delivered after an unpredictable number of responses (e.g., after 1, 4, 5, and 9 responses). | High and steady response rate | Gambling |
Now let’s combine these four terms. A fixed interval reinforcement schedule is when behavior is rewarded after a set amount of time. For example, June undergoes major surgery in a hospital. During recovery, she is expected to experience pain and will require prescription medications for pain relief. June is given an IV drip with a patient-controlled painkiller. Her doctor sets a limit: one dose per hour. June pushes a button when pain becomes difficult, and she receives a dose of medication. Since the reward (pain relief) only occurs on a fixed interval, there is no point in exhibiting the behavior when it will not be rewarded.
With a variable interval reinforcement schedule, the person or animal gets the reinforcement based on varying amounts of time, which are unpredictable. Say that Manuel is the manager at a fast-food restaurant. Every once in a while someone from the quality control division comes to Manuel’s restaurant. If the restaurant is clean and the service is fast, everyone on that shift earns a $20 bonus. Manuel never knows when the quality control person will show up, so he always tries to keep the restaurant clean and ensures that his employees provide prompt and courteous service. His productivity regarding prompt service and keeping a clean restaurant are steady because he wants his crew to earn the bonus.
With a fixed ratio reinforcement schedule, there are a set number of responses that must occur before the behavior is rewarded. Carla sells glasses at an eyeglass store, and she earns a commission every time she sells a pair of glasses. She always tries to sell people more pairs of glasses, including prescription sunglasses or a backup pair, so she can increase her commission. She does not care if the person really needs the prescription sunglasses, Carla just wants her bonus. The quality of what Carla sells does not matter because her commission is not based on quality; it’s only based on the number of pairs sold. This distinction in the quality of performance can help determine which reinforcement method is most appropriate for a particular situation. Fixed ratios are better suited to optimize the quantity of output, whereas a fixed interval, in which the reward is not quantity based, can lead to a higher quality of output.
In a variable ratio reinforcement schedule, the number of responses needed for a reward varies. This is the most powerful partial reinforcement schedule. An example of the variable ratio reinforcement schedule is gambling. Imagine that Sarah—generally a smart, thrifty woman—visits Las Vegas for the first time. She is not a gambler, but out of curiosity she puts a quarter into the slot machine, and then another, and another. Nothing happens. Two dollars in quarters later, her curiosity is fading, and she is just about to quit. But then, the machine lights up, bells go off, and Sarah gets 50 quarters back. That’s more like it! Sarah gets back to inserting quarters with renewed interest, and a few minutes later she has used up all her gains and is $10 in the hole. Now might be a sensible time to quit. And yet, she keeps putting money into the slot machine because she never knows when the next reinforcement is coming. She keeps thinking that with the next quarter she could win $50, or $100, or even more. Because the reinforcement schedule in most types of gambling has a variable ratio schedule, people keep trying and hoping that the next time they will win big. This is one of the reasons that gambling is so addictive—and so resistant to extinction.
Watch It
Review the schedules of reinforcement in the following video.
In operant conditioning, extinction of a reinforced behavior occurs at some point after reinforcement stops, and the speed at which this happens depends on the reinforcement schedule. In a variable ratio schedule, the point of extinction comes very slowly, as described above. But in the other reinforcement schedules, extinction may come quickly. For example, if June presses the button for the pain relief medication before the allotted time her doctor has approved, no medication is administered. She is on a fixed interval reinforcement schedule (dosed hourly), so extinction occurs quickly when reinforcement doesn’t come at the expected time. Among the reinforcement schedules, variable ratio is the most productive and the most resistant to extinction. Fixed interval is the least productive and the easiest to extinguish (Figure 1).
Connect the Concepts: Gambling and the Brain
Skinner (1953) stated, “If the gambling establishment cannot persuade a patron to turn over money with no return, it may achieve the same effect by returning part of the patron’s money on a variable-ratio schedule” (p. 397).
Figure 2. Some research suggests that pathological gamblers use gambling to compensate for abnormally low levels of the hormone norepinephrine, which is associated with stress and is secreted in moments of arousal and thrill. (credit: Ted Murphy)
Skinner uses gambling as an example of the power and effectiveness of conditioning behavior based on a variable ratio reinforcement schedule. In fact, Skinner was so confident in his knowledge of gambling addiction that he even claimed he could turn a pigeon into a pathological gambler (“Skinner’s Utopia,” 1971). Beyond the power of variable ratio reinforcement, gambling seems to work on the brain in the same way as some addictive drugs. The Illinois Institute for Addiction Recovery (n.d.) reports evidence suggesting that pathological gambling is an addiction similar to a chemical addiction (Figure 2). Specifically, gambling may activate the reward centers of the brain, much like cocaine does. Research has shown that some pathological gamblers have lower levels of the neurotransmitter (brain chemical) known as norepinephrine than do normal gamblers (Roy, et al., 1988). According to a study conducted by Alec Roy and colleagues, norepinephrine is secreted when a person feels stress, arousal, or thrill; pathological gamblers use gambling to increase their levels of this neurotransmitter. Another researcher, neuroscientist Hans Breiter, has done extensive research on gambling and its effects on the brain. Breiter (as cited in Franzen, 2001) reports that “Monetary reward in a gambling-like experiment produces brain activation very similar to that observed in a cocaine addict receiving an infusion of cocaine” (para. 1). Deficiencies in serotonin (another neurotransmitter) might also contribute to compulsive behavior, including a gambling addiction.
It may be that pathological gamblers’ brains are different than those of other people, and perhaps this difference may somehow have led to their gambling addiction, as these studies seem to suggest. However, it is very difficult to ascertain the cause because it is impossible to conduct a true experiment (it would be unethical to try to turn randomly assigned participants into problem gamblers). Therefore, it may be that causation actually moves in the opposite direction—perhaps the act of gambling somehow changes neurotransmitter levels in some gamblers’ brains. It also is possible that some overlooked factor, or confounding variable, played a role in both the gambling addiction and the differences in brain chemistry.