lecture 3 - Nic Hooper, PhD
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Behavior Analysis LECTURE3 INCREASING THE FREQUENCY OF BEHAVIOR REINFORCEMENT
Review We are studying applied behavior analysis, which is
the attempt to solve problems by providing antecedents and consequences that change behavior There are broadly two types of behavior problems
Those that don’t occur enough Those that occur too much
Todays lesson is going to focus on the first problem Can anyone think of any examples? So the question is, how do we increase the frequency
Law of Effect The law of effect has to do with the idea that the strength of
behavior depends on the effect it has on the environment
Law of effect: in any given situation, the probability of a behavior occurring is a function of the consequences that behavior has had, in that situation, in the past. Law of effect was created by one of the earliest behaviorists, E.L.
Thorndike, who near enough invented the field of educational psychology.
This principle recognized that whether a behavior is repeated
depends on the effects the behavior has had in the past
Law of effect: behavior is a function of its consequences
Reinforcement The law of effect draws our attention to the
important role that environmental consequences play in behavior It also provides the basis for probably the most important tool we have for changing behavior: reinforcement Reinforcement: the procedure of providing consequences for a behavior that increase or maintain the frequency of that behavior
Reinforcement Reinforcement is a natural tool that engulfs our everyday lives When you hit a nail and it holds the wood together, that consequence reinforces your use of the hammer When you hang clothes to dry, and they do actually dry, that consequence reinforces your behavior of hanging clothes in the sun However it is also a tool we can use to solve behavior
problems If a behavior does not occur enough, we can increase its frequency by providing reinforcing consequences. Such consequences are called reinforcers Reinforcer: an event that, when made contingent on a behavior, increases or maintains the frequency of that behavior
Reinforcement Note reinforcer is not synonym for reward Why? Because a reward is defined by consensus, where as reinforcers are defined by results In other words what would generally be thought of as
rewarding by ‘most’ people will not be reinforcing to everyone. Reinforcers are defined by their ability to maintain or increase behavior. In order to find this out we have to study the results of applying a reinforcer
Reinforcement Example: are the words mm-hmmm a reward? No, most people would probably agree that those words are not a reward
But could they be a reinforcer? Joel Greenspoon asked participants to say as many words as they could. Every time they came up with a plural noun i.e. horses, bananas, books etc. he would say the words mmhmmm. What he found was that the sound reinforced the behavior of saying plural nouns, because participant increased the amount of plural nouns they used compared to control
Kinds of Reinforcers There are broadly two types of reinforcers: positive
and negative Positive reinforcer: a reinforcing event in which something is added following a behavior
Negative reinforcer: a reinforcing event in which something is removed following a behavior
Positive reinforcer When a favorable event or outcome follows an action,
that action is more likely to occur in future – this is positive reinforcement.
After you write a good essay your tutor says to you ‘good job’. Making it more likely that you will repeat this behavior in the future After you exceed the months sales bonus you receive a monetary bonus, making more likely that you will work hard for the bonus in the future
In these examples ‘good job’ and ‘monetary bonus’ are
reinforcers that are added to the situation
Negative reinforcer In negative reinforcement a behavior is strengthened by
stopping, removing or avoiding a negative outcome or aversive stimulus
For example, if your parents are arguing then you stay in your bedroom out of the way, being away from the stress of the argument makes it likely you will repeat this behavior in the future. You leave for work early on a Monday morning in order to avoid traffic. When you do avoid the traffic the response is strengthened
Here seeing your parents fight and avoiding traffic were
negative outcomes that were avoided by performing specific behaviors. These behaviors were therefore strengthened. By eliminating these undesirable outcomes, the preventative behaviors become more likely to occur again
Another example: nagging. A person will often do the desired behavior in order to avoid any more nagging, this is negative reinforcement
Summary of positive and negative reinforcement Every situation involves behavior and consequence If the consequence of engaging in a behavior is appetitive (+) then
the behavior is likely to be repeated in the future. This is positive reinforcement. If the consequence has been experienced as aversive in the past (-) then the behavior will attempt to reduce contact with the aversive outcome. If the behavior succeeds in avoiding the aversive outcome, then it will likely be repeated in the future.
Example, imagine you're in a club and a good looking boy starts talking to you, you want him to hang around. So you buy him a drink and he hangs around. Next time you’re in this situation do you think you will repeat the behavior? This is positive reinforcement, the likelihood of you repeating the behavior following the episode has increased. Now imagine you're in a club and an annoying boy starts talking to you but you want him to leave. So you ignore him and he leaves. Next time you're in this situation do you think you will repeat the behavior? This is negative reinforcement, the likelihood of repeating the behavior following the episode has increased.
Primary and Secondary reinforcers There are other ways of classifying reinforcers
worthy of discussion. All reinforcers can be classified as primary or secondary
Primary reinforcers: reinforcers that are not dependent on their association with other reinforcers Secondary reinforcers: reinforcers that are dependent on their association with other reinforcers
Primary reinforcers Primary reinforcers tend to include environmental
stimuli that include basic human needs, and therefore are often concerned with biological processes
Food Oxygen Water Warmth Sexual stimulation
Secondary reinforcers Secondary reinforcers depend on learning. This means
that they acquire their reinforcing powers through their association with other reinforcers.
For example, if a parent smiles when providing food to the baby, and the food is reinforcing, the smiles will become reinforcing.
Secondary reinforcers get their name from the fact that
they are ultimately derived from, and secondary to, primary reinforcers What does this business of pairing neutral events with reinforcing stimuli remind you of?
If you make a list of the majority of things that you do in
your life and they will most probably be secondary reinforcers
Contrived and Natural reinforcers There are two further ways to categories reinforcers:
Contrived reinforcers: reinforcers that have been arranged by someone for the purpose of modifying behavior
Natural reinforcers: reinforcers that have not been arranged by someone for the purposes of modifying behavior; spontaneous or unplanned reinforcers
Contrived and Natural reinforcers Imagine after getting a question correct, the teacher
smiles and winks at the little boy. The smile and the wink have been put in place, on purpose, by the teacher in order to positively reinforce the behavior. This is a contrived reinforcer.
Now imagine a little girl smiles and winks at the boy, this
is more like a natural reinforcer as the girl is not trying to increase the boys behavior.
Lets look at some studies that illustrate the use of
Ann doesn't’t socialize Allen at el (1964) studied a little girl who showed
very little interest in interacting with other children. She did enjoy interacting with adults however. Since adult attention seemed to be reinforcing, the researchers decided that the teachers should only provide attention to Ann only when she interacting with another child How would you do this study?
This is how they did it Two observers took a tally sheet and counted interactions
every morning for five days in order to get a baseline
What is a baseline?
At the end of the baseline period, teachers started
providing special attention to Ann whenever she interacted with other children. If she played alone, the teachers would pay her no attention
Reinforcement via attention was the intervention
The researchers then again counted interactions and
expected an increase in the amount of contact she had with other children
Results However they did not find the expected increase.
Apparently the teachers comment drew Anns attention towards the teacher, and not towards the child.
Teacher attention was therefore not a reinforcer for Ann.
If one consequence proves ineffective then we have to try
another! And that’s what the researchers did. Now the teacher would give Ann a toy or utensil to use in the ongoing activity as the new reinforcer. The new reinforcement produced a dramatic change in Ann’s behavior
During baseline Ann spent 10% of her time playing with other children After the intervention Ann spent 60% of her time playing with other children
ABAB reversal design Importantly, after researchers had increased Ann’s social
behavior, they wanted to make sure that it was their intervention that was powering the results. They therefore asked teachers to stop reinforcing playing with the group. Social play immediately dropped back to baseline Then teachers began reinforcing again, and the behavior shot up to 60% again Of course a teacher would be unlikely to use ABAB design in real life
Lets consider a more difficult problem
Mary refuses to eat Mary was admitted to hospital because she claimed her food
was being poisoned and she refused to eat Because of her low weight, the nurses took to spoon feeding her. The goal was to get Mary to feed herself Mary seemed to take good care of herself; she always kept her clothes neat and clean This gave the researchers, Teodoro Ayllon and Jack Michael, an idea They asked nurses to continue to feed Mary, but to be careless when doing it i.e. spill food on her dress The idea was to get Mary to eat on her own, to avoid getting her dress messy
Results During an 8 day baseline period, Mary ate 5 meals on
her own, was spoon fed 12 meals, and refused to eat on 7 occasions
Once the nurses became sloppy, this began to
After a while she began feeding herself on all
occasions, she skipped fewer meals, she gained 21 pounds in weight and she was discharged from hospital
Rules for using reinforcement This course is not a training manual, however all of
you have the opportunity to use reinforcement in your every day interactions with others And some of you will be in occupations where reinforcement is crucial (teaching, counseling, health care etc.) Just in case any of you leave here thinking about employing reinforcement techniques to increase behavior, lets go through some basic rules:
1. Define the Target Behavior We cant implement an effective intervention if we
don’t have a clear idea of what behavior we are trying to change.
This means that you should quite literally write a brief description of the behavior
Remember here that you should be identifying
behaviors that the person should do, not behaviors which they should not do
‘Not running around so much’ and ‘not being so active’ do not work as were trying to increase the behavior
2. Select appropriate reinforcers Before you can reinforce the behavior, you have to select one
of more reinforcers. There are a few rules that will help you make a good choice
1. Use positive reinforcers. Stay away from negative reinforcers
as they involve aversives, and aversives have some serious side effects (more about this at a later lecture) 2. Use secondary reinforcers – primary reinforcers tend to satiate very quickly, where as secondary reinforces tend to hold their power 3. Use natural reinforcer – where possible allow people to contact natural reinforcers rather than contrived reinforcers i.e. let them see that certain behaviors are reinforcing in and of themselves. Often it will be very difficult to do this.
3. Make reinforcers immediate and certain Two major factors can affect the power of reinforcement: How quickly the reinforcer follows the behavior The closer the target behavior is followed by the reinforcer, the more likely the reinforcer will be effective. Time delay allows for other behavior to occur which could then be reinforced How likely the reinforcer is to follow the behavior The more likely the target behavior is to result in reinforcement, the more rapidly the behavior will increase in strength Its important not to hand out reinforcement all the time, it must be contingent on the target behavior, and only on the target behavior If you don’t follow these rules then you may see little effect from you
4. Monitor results In applied behavior analysis, we have to monitor the
result of every intervention, usually on a daily basis, and modify the intervention in accordance with the data obtained If you fail to monitor the results in a formal way, how
will you know if the intervention has worked?
Problems with reinforcement You may look at reinforcement and think it looks easy.
Remember that this is a beginner course, and that it will take lots of time and practice to perfect.
Nevertheless you should be able to see how
reinforcement plays a part in our everyday lives.
So before you leave here you should know some of the
negative sides of reinforcement:
Inappropriate use Moral objections Negative side effects
Inappropriate use The argument has been made that reinforcement can
make things worse. And this can be the case:
Imagine the truck driver who gets paid by the mile – he is being reinforced to drive fast and for long hours. Its hardly surprising that many accidents occur because of truck drivers falling asleep at the wheel!
Another issue is where reinforcement can come from
sources other than the person designing the intervention
Imagine the school child who does’t raise his hand as the teacher wants, but receive the approval of the class when they laugh at his witty comment.
Bootleg reinforcement: reinforcement that is not part of, and tends to undermine, an intervention
Moral objections Some people think that ABA interventions are
manipulative and controlling And that it puts too much trust into the person
intervening. What right do we have to change someone else’s behavior? Others say that reinforcement makes changing too
easy and too pleasant and that there is virtue in suffering
Negative side effects People think have suggested that those who have
knowingly been reinforced for particular behaviors will go through the rest of their life expecting reward or praise.
For example, it is said that if students receive recognition for behaving well and learning, then they will no longer work hard and learn when such benefits are no longer available
This would be a strong argument if it were true, but
it isn't. (see Dickinson et al, 1974, who tracked the progress of students who underwent a reward scheme)
Negative side effects One particular problem that can arise is called
behavioral contrast Behavioral contrast: the tendency for a reinforced behavior to occur less often in situations in which it has not been reinforced. It is possible that although the intervention may
cause an increase in target behavior in one setting, it may be lost in another.
Flashcard Law of effect the probability of a behavior occurring is a function of the consequences that behavior has had in that situation in the past; behavior is a function of its consequences Reinforcement procedure of providing consequences for a behavior that increase or maintain the frequency of that behavior Reinforcer event that, when made contingent on a behavior, increases or maintains the frequency of that behavior Positive reinforcer a reinforcing event in which something is added following a behavior Negative reinforcer a reinforcing event in which something is removed following a behavior
Flashcard Primary reinforcers reinforcers that are not dependent on their association with other reinforcers Secondary reinforcers reinforcers that are dependent on their association with other reinforcers Contrived reinforcers reinforcers that have been arranged by someone for the purpose of modifying behavior Natural reinforcers reinforcers that have not been arranged by someone for the purpose of modifying behavior; spontaneous or unplanned reinforcers Bootleg reinforcement reinforcement that is not part of, and tends to undermine, an intervention Behavioural contrast tendency for a reinforced behavior to occur less often in situations in which it has not been reinforced