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Extinction and Stimulus Control Chapter 8 1
Side Effects of Extinction 2
Extinction Burst.
a temporary increase in the frequency and intensity of responding when extinction is first implemented. In a FR4 schedule, when extinction is implemented, the rat will initially react by pressing the lever both more rapidly and more forcefully. Increase in Variability. If the rat typically pressed the lever with its right paw, it might now try pressing it with its left paw. Or if the rat usually pressed the lever in the center, it might now press it more to one side.
Side Effects of Extinction
Side Effects of Extinction
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Emotional Behavior.
Resurgence.
becoming agitated, upset. These emotional responses are are what we typically refer to as frustration. Aggression. A pigeon without reward will reliably attack another pigeon. People often become angry with those who block them from obtaining an important goal.
the reappearance during extinction of other behaviors that had once been effective in obtaining reinforcer. e.g. Rats first run a 20-foot pattern in a maze to obtain food, then a 40-foot pattern. When extinction is implemented , the rats initially persisted with the 40-foot pattern, then returned to the 20-foot pattern before quitting. e.g. a husband faced with a wife who largely ignores him might begin spending increasing amounts of time at his parents’ house.
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Side Effects of Extinction
Side Effects of Extinction (Examples)
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Depression.
Krissy asked her father to buy her a toy, as he
usually did, when they were out shopping. Unfortunately, Krissy’s father had spent all of his money on building supplies and told her that he had nothing left for a toy. The first thing that might happen is that Krissy will (increase/decrease) _______ the frequency with which she asks for a toy and ask for a toy with a (louder/softer) ____ voice. This process is known as an e________ b________.
depressive-like symptoms.
Side Effects of Extinction (Examples)
Resistance to Extinction
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Krissy is also likely to ask for the toy in many different
ways because extinction often results in an increase in the v________ of a behavior.
Responding persists after an extinction procedure
has been implemented. A response that is very persistent is said to have high
resistance to extinction! When her father still refuses to buy her a toy, Krissy
suddenly asks her dad to pick her up and carry her, something she has not asked for since she was much smaller. This could be an example of r_______. On the trip home, Krissy, who never did get a toy, sat silently and stared out the window. This is not surprising, because extinction is sometimes followed by a temporary period of d_______________.
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Factors of Resistance to Extinction
Factors of Resistance to Extinction
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Factors of Resistance to Extinction
Factors of Resistance to Extinction
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Schedule of Reinforcement.
Schedule of Reinforcement.
Behavior that is acquired with PRF will extinguish more slowly than behavior that is acquired with CRF. FR 10 schedule > CRF (FR 1) schedule FR 100 schedule > FR 10 schedule VR 20 schedule >?< FR 20 schedule Key: the less frequent the reinforcer, the longer it takes the animal to “discover” that reinforcement is no longer available.
Another explanation: contrast between a CRF schedule and extinction or contrast between a VR 100 schedule and extinction. Which contrast is greater? On a VR 100 schedule, the animal has learned to emit many responses in the absence of reinforcement.
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Factors of Resistance to Extinction
Factors of Resistance to Extinction
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History of Reinforcement.
Degree of Deprivation.
The more reinforcers an individual has received for a behavior, the greater the resistance to extinction. e.g. 100 reinforcers > 10 reinforcers Magnitude of the Reinforcer. Large-magnitude reinforcers sometimes result in greater resistance to extinction than small-magnitude reinforcers. large pellet of food > small pellet of food Also, highly preferred food > less preferred food
the greater the level of deprivation, the greater the resistance to extinction. e.g. a very hungry rat > a slightly hungry rat Previous Experience With Extinction. the greater the number of prior exposures to extinction, the quicker the behavior will extinguish. e.g. a child might learn that if he does not receive candy within the first 10 minutes of whining at the supermarket, s/he might give up.
Factors of Resistance to Extinction
Differential Reinforcement of Other Behavior
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Distinctive Signal for Extinction.
Extinguishing the target behavior and reinforcing
when there is a distinctive stimulus that signals the
the occurrence of a replacement behavior. (DRO) e.g. Paying attention to a child only if he is doing something other than fighting with his little sister.
onset of extinction, behavior disappears quickly. Resistance to extinction is generally greater when the
behavior that is being extinguished has been reinforced with a (high/low) _________-magnitude reinforcer, though the opposite effect has also been found. In general, there is a(n) (direct/inverse______
relationship between resistance to extinction and the organism’s level of deprivation for the reinforcer.
Reinforcing a behavior that is specifically
incompatible with the target behavior. (differential reinforcement of incompatible behavior (DRI)) e.g. paying attention to him only when he is interacting in a friendly manner with his little sister.
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Differential Reinforcement of Other Behavior 17
They are strong and effective because the target
behavior is weakened both by the lack of reinforcement and by the reinforcement of alternative behaviors that come to replace it.
Differential Reinforcement of Other Behavior 18
Giving a dog food whenever it does something other than
jump up on visitors as they enter the house is an example of a (use the abbreviation) ____________ procedure. Giving a dog a treat for sitting quietly when visitors enter the house is an example of a _______ procedure.
Differential reinforcement procedures can reduce
many of the unwanted side effects of extinction, such as frustration and aggression. The individual still can get the reinforcer.
Stimulus Control
The Peak Shift Effect
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The presence of a discriminative stimulus reliably
affects the probability of the behavior.
A discriminative stimulus for extinction is typically
given the symbol SΔ, signals the absence of reinforcement.
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The Peak Shift Effect 21
We first train a rat to press a lever in the presence of
a 2,000-Hz tone. We then conduct a test for generalization across a
range of tones varying in pitch between 1,200 and 2,800 Hz.
The Peak Shift Effect 23
A man identifies women entirely on the basis of how
extraverted versus introverted they are. He had a very boring relationship with Jackie, the introvert
(SΔ). On the other hand, he had a wonderfully exciting relationship with Dana, the extravert (SD). He then moves to a new city and starts to meet singles there. According to the peak shift effect, he will likely seek out a woman who is even more extraverted than Dana. Why? Because he is attempting to find a woman who is even more dissimilar from Jackie, with whom he had such a poor relationship or he chooses a woman who is even more extraverted than Dana because greater extraversion is associated with a better relationship.
The Peak Shift Effect 22
After that we submit the rat to a discrimination
training procedure in which we reinforce lever pressing in the presence of a 2,000-Hz tone (SD) and not in the presence of a 1,200-Hz tone (SΔ). The strongest response shifts away from the SD to a stimulus that lies in a direction opposite to the SΔ. This shift in the peak of the generalization gradient is the peak shift effect.
The Peak Shift Effect 24
If an orange key light is trained as an SD in a key pecking
task with pigeons, and the pigeons are then exposed to other key colors ranging from yellow on one end of the continuum to red on the other (with orange in the middle), then the peak of the generalization gradient will likely be to a (yellowish-orange/orange/orange-reddish) _______key light. If a pigeon undergoes discrimination training in which a yellow key light is explicitly established as an SΔ and an orange key light is explicitly established as the SD, the strongest response in the generalization gradient will likely be to a (yellowish-orange/orange/orange-reddish) ______ key light. This effect is known as the _______ _______ effect.
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Stimulus Control
The Peak Shift Effect
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The presence of a discriminative stimulus reliably
affects the probability of the behavior.
A discriminative stimulus for extinction is typically
given the symbol SΔ, signals the absence of reinforcement.
The Peak Shift Effect 27
We first train a rat to press a lever in the presence of
a 2,000-Hz tone. We then conduct a test for generalization across a
range of tones varying in pitch between 1,200 and 2,800 Hz.
The Peak Shift Effect 28
After that we submit the rat to a discrimination
training procedure in which we reinforce lever pressing in the presence of a 2,000-Hz tone (SD) and not in the presence of a 1,200-Hz tone (SΔ). The strongest response shifts away from the SD to a stimulus that lies in a direction opposite to the SΔ. This shift in the peak of the generalization gradient is the peak shift effect.
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The Peak Shift Effect 29
A man identifies women entirely on the basis of how
extraverted versus introverted they are. He had a very boring relationship with Jackie, the introvert
(SΔ). On the other hand, he had a wonderfully exciting relationship with Dana, the extravert (SD). He then moves to a new city and starts to meet singles there. According to the peak shift effect, he will likely seek out a woman who is even more extraverted than Dana. Why? Because he is attempting to find a woman who is even more dissimilar from Jackie, with whom he had such a poor relationship or he chooses a woman who is even more extraverted than Dana because greater extraversion is associated with a better relationship.
The Peak Shift Effect 30
If an orange key light is trained as an SD in a key pecking
task with pigeons, and the pigeons are then exposed to other key colors ranging from yellow on one end of the continuum to red on the other (with orange in the middle), then the peak of the generalization gradient will likely be to a (yellowish-orange/orange/orange-reddish) _______key light. If a pigeon undergoes discrimination training in which a yellow key light is explicitly established as an SΔ and an orange key light is explicitly established as the SD, the strongest response in the generalization gradient will likely be to a (yellowish-orange/orange/orange-reddish) ______ key light. This effect is known as the _______ _______ effect.
Multiple Schedules and Behavioral Contrast
Multiple Schedules and Behavioral Contrast
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consists of two or more independent schedules presented
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in sequence, each resulting in reinforcement and each having a distinctive SD. E.g. a pigeon might first be presented with a red key that signals an FI 30-sec schedule. And then the key light changes to green, which signals a VI 30-sec schedule.
Result: a pigeon will likely show a scalloped pattern of
responding on the red key signaling the FI component, and a moderate, steady pattern of responding on the green key signaling the VI component.
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Behavioral Contrast 33
Behavioral Contrast
Behavioral contrast occurs when a change in the rate of
a negative contrast effect;
reinforcement on one component of a multiple schedule produces an opposite change in the rate of response on another component. two basic contrast effects: positive and negative.
Firstà
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And then,
In a negative contrast effect, an increase in the rate of
reinforcement on one component produces a decrease in the rate of response on the other component. In a positive behavioral contrast, a decrease in rate of
VI 30-sec provides a higher rate of reinforcement. With more reinforcement now available on the red key, the
reinforcement on one component results in an increase in rate of response on the other component.
pigeon will decrease its rate of response on the green key. Because the first component in the sequence is now more attractive, the second component seems relatively less attractive.
Behavioral Contrast
Behavioral Contrast
a positive contrast effect;
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Firstà
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A pigeon that experiences a shift from a multiple FR 10 VI 60-sec
schedule to a multiple FR 100 VI 60-sec schedule will likely (increase/ decrease) ________ its rate of response on the VI 60-sec component. When Levin proposed to the beautiful young Kitty, she rejected him.
And then,
VI 120-sec provides a lower rate of reinforcement. With less reinforcement now available on the red key, the
pigeon will increase its rate of response on the green key.
Levin was devastated and decided to devote the rest of his life to his work. Kitty, in turn, was subsequently rejected by the handsome young military officer, Vronsky, whom she had mistakenly assumed was intent on marrying her. Kitty was devastated and deeply regretted having turned down Levin, whom she now perceived to be a fine man. A year later, they encountered each other at a social gathering. Relative to individuals who have not experienced such hardships in establishing a relationship, we would expect their affection for each other to be much (deeper/shallower) _________________ than normal. This can be seen as an example of (positive/negative) ___________________ behavioral contrast.
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Behavioral Contrast
Behavioral Contrast
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An additional type of contrast effect is anticipatory contrast
It’s an increase in the rate of responding for an available reinforcer when faced with the possibility of losing it in the near future. e.g. If Jackie hears her mother say that it is getting close to her bedtime, she is likely to become more involved in the computer game she is playing. E.g. Lindsay views her relationship with Bryce as rather uninteresting until she learns that Bryce might be romantically interested in another woman. Faced with the possibility that she might lose him, she now becomes intensely interested in him.
Fading and Errorless Discrimination Learning
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The occurrence of these contrast effects indicates that
behaviors should not be viewed in isolation. Consequences for behavior in one setting can greatly affect the strength of behavior in another setting. E.g. a young girl who is increasingly neglected at home,
perhaps because her parents are going through a divorce. She might try to compensate for this circumstance by seeking more attention at school (a positive contrast effect), perhaps to the point of misbehaving. Although the parents might blame the school for her misbehavior, she is in fact reacting to the lack of reinforcement at home.
Fading and Errorless Discrimination Learning
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During the process of learning to discriminate an
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SD
from an SΔ ,the subject will make several “mistakes” by Δ responding in the presence of the S . Such responses do not result in reinforcement, so the subject might get frustrated and display emotional behavior. Hence, it would be helpful, if there were a method of discrimination training that minimized these effects.
Errorless discrimination training is a procedure that
minimizes the number of errors (i.e., nonreinforced responses to the SΔ) and reduces many of the adverse effects associated with discrimination training. involves two aspects:
(1) The SΔ is introduced early in training, soon after the animal has learned to respond appropriately to the SD, and (2) the SΔ is presented in weak form to begin with and then gradually strengthened.
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Fading and Errorless Discrimination Learning 41
Terrace used errorless discrimination training to establish a red–green
discrimination in pigeons. The pigeons were first trained to peck a red key on a VI 60-sec
schedule. And then the key light was switched off for 5 sec. (extinction period) The dark key was easily established as an effective SΔ for not
Fading and Errorless Discrimination Learning 42
What happens to the pigeons that were exposed to standard
discrimination training? Dark key was suddenly replaced by a brightly lit green key,
made numerous responses on it before finally discriminating it from the red SD.
responding. The VI period and the extinction period were then gradually
lengthened until they each lasted 3 minutes. the dark key was illuminated with a faint greenish hue that was slowly intensified. As the green key color was faded in (as an SΔ) and gradually replaced the dark key, the pigeons emitted almost no responses toward it; that is, they made almost no errors.
Fading and Errorless Discrimination Learning 43
Have some have practical applications. Like enhancing the
learning of basic arithmetic skills… E.g. a 9-year-old girl trying to learn addition and
subtraction problems. Standard procedure for addition problemsà presenting the
problems on flash cards. the answers were initially covered. If the child did not know the answer, the answer was uncovered and shown to her. Errorless discrimination training for substraction problemsà the answer on each flash card was initially uncovered to view and then, over successive presentations, gradually blocked out by adding successive sheets of cellophane. The correct answer was initially available and then gradually faded out.
In summary, in errorless discrimination training, the SΔ
must be presented early in the training procedure, and at very weak intensity to begin with. This type of discrimination training is likely to produce less emotional behavior compared to the standard form of discrimination training.
Stimulus Control Procedures for the Study of Memory 44
Some behaviorists have also participated by studying
cognitive processes in animals. The field of animal cognition. Memory processes in animals. However animals do not
have verbal ability, so how can we study their memory? The animal is shown a certain stimulus and is then required
to identify that stimulus at a later time in order to receive a reinforcer. A procedure to use is called ‘delayed matching-to-sample’. In delayed matching-to-sample, the animal is first shown a sample stimulus and then, following some delay, is required to select that stimulus out of a group of alternative stimuli. To the extent that the animal is able to select the correct stimulus, it can be said to remember it.
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Delayed matching-to-sample 45
The chamber contains 3 response keys. In the basic procedure, the two side keys are initially dark while a sample stimulus, such as a triangle, is shown on the center key.
Delayed matching-to-sample 46
When the pigeon pecks this sample stimulus, a delay period is entered in which all three keys are dark. Following the delay period, a test period is entered in which the center key is dark and the two side keys are illuminated, one with a triangle and the other with a square. Pecking the triangle (which “matches the sample”) is immediately reinforced with food. To earn food, the pigeon must select the correct alternative by remembering which stimulus it was shown before the delay.
Stimulus Control Procedures for the Study of Memory 47
One can change some aspects in the experimental design
such as similarity of the stimuli during the test phase, the length of time the sample stimulus is presented, the length of the delay period. A particularly interesting concept that has been
investigated is called ‘directed forgetting’. Directed forgetting occurs when you have been told to forget something.
Directed forgetting 48
The sample stimulus is presented as usual. During the delay period, however, the pigeon is shown either an O on the center key, which indicates that it must remember the sample stimulus. the O tells the pigeon that everything is okay and that the test phase will be occurring as normal, whereas the X tells the pigeon something like, “Whoops, made a mistake; we’ll be starting over again, so you may as well forget what you’ve just been shown.”
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Directed forgetting 49
The question is whether pigeons are actually less likely to remember the sample stimulus when they have been shown the X (the forget cue) as opposed to the O (the remember cue).
Stimulus Control: Additional Applications 50
stimulus control to manage behaviors by animal trainers. Targeting involves using the process of shaping to train an
animal to approach and touch a particular object. Targeting is commonly used to manage animals in zoos.
So, presenting the X and then proceeding to the test phase. When the pigeons are “told” that they need not remember a particular stimulus, they do in fact display poorer memory for that stimulus in the future.
Stimulus Control: Additional Applications
Stimulus Control: Additional Applications
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Stimulus control is obviously an important aspect of
human behavior. E.g. the person who remembers to take his umbrella in the morning is the person who sets it beside the door the night before when he hears that it will likely rain next day. E.g. one who should take his/her vitamins every evening can place the vitamin bottle beside the alarm clock that she sets each evening. This is creating a salient cue for taking vitamins.
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Stimulus control is also useful for creating an effective
study environment. Skinner (1987) recommends establishing a particular
setting, such as a certain desk, that is used only for studying. Over time, the desk will become so strongly associated with the act of studying that just sitting at the desk will facilitate one’s ability to study. Of course, just sitting at a desk for 3 hours trying to study but daydreaming instead will only associate the desk with the act of daydreaming. Instead, one can try to begin with short, high-quality study periods and then gradually progress to longer study periods
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Stimulus Control: Additional Applications 53
Stimulus control procedures are also the treatment of
choice for sleep-onset insomnia, in which people have difficulty falling asleep. For example, Bootzin, Epstein, and Wood (1991) recommend the following procedure: The key is to make lying in bed a strong cue for sleeping! 1. Go to bed only when you are sleepy. 2. Use the bed only for sleeping. Do not lie in bed to read, study, or watch television. 3. If you cannot fall asleep within 10 to 20 minutes, get out of bed and go to another room. Go back to bed only when you feel sleepy. 4. Repeat the above rule as often as necessary. This rule should also be applied if you are unable to fall asleep after a middle-of-the-night awakening. 5. Use your alarm to get up at the same time each morning, regardless of how you slept the night before. 6. Do not take naps during the day.
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