PSY381 Chapter 8: Extinction and Stimulus Control PDF

PSY381-Assoc Prof Hande Kaynak 10/10/2023 “No one is born hating another person because of the color of his skin, or his background, or his religion. People must learn to hate, and if they can learn to hate, they can be taught to love, for love comes more naturally to the human heart than its oppo...

PSY381-Assoc Prof Hande Kaynak 10/10/2023 “No one is born hating another person because of the color of his skin, or his background, or his religion. People must learn to hate, and if they can learn to hate, they can be taught to love, for love comes more naturally to the human heart than its opposite.” Nelson Mandela Extinction and Chapter 8 Stimulus Control 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 3  Emotional Behavior. becoming agitated, upset. These emotional responses 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. Side Effects of Extinction  Resurgence. 4 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. 1 PSY381-Assoc Prof Hande Kaynak 10/10/2023 Side Effects of Extinction Side Effects of Extinction (Examples) 5 6  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) 7  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.  When her father still refuses to buy her a toy, Krissy Resistance to Extinction 8  Responding persists after an extinction procedure has been implemented.  A response that is very persistent is said to have high resistance to extinction! 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_______, or what psychoanalysts call 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_______________. 2 PSY381-Assoc Prof Hande Kaynak 10/10/2023 Low Resistance to Extinction Factors of Resistance to Extinction 9 10  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 (Resistance to extinction is strong when behavior has been maintained on a variable ratio schedule) Key: the less frequent the reinforcer, the longer it takes the animal to “discover” that reinforcement is no longer available. Factors of Resistance to Extinction Factors of Resistance to Extinction 11 12  Schedule of Reinforcement. 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.  History of Reinforcement. 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 3 PSY381-Assoc Prof Hande Kaynak 10/10/2023 Factors of Resistance to Extinction Factors of Resistance to Extinction 13 14  Degree of Deprivation. 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 for the day.  Distinctive Signal for Extinction. When there is a distinctive stimulus that signals the onset of extinction, behavior disappears quickly.  A discriminative stimulus may signal the occurrence of extinction; that is, the stimulus signals the nonavailability of a previously available reinforcer. The buzzer signals the absence of reinforcement. the symbol SΔ What you resist, persists. Carl Jung Examples: Factors of Resistance to Extinction 15 Examples: Factors of Resistance to Extinction 16  According to the p_______r______ effect, responses that 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. have been maintained on an intermittent schedule will show (more/less) _______ resistance to extinction than responses that have been reinforced on a continuous schedule.  Among the 4 basic intermittent schedules, the (use the abbreviation)____schedule is likely to produce strong resistance to extinction.  In general, a behavior that has been reinforced many times is likely to be (much easier/more difficult) ____ to extinguish.  Previous experience with extinction, as well as a distinctive signal for extinction, tends to produce a(n) (increase/decrease) _______ in resistance to extinction. 4 PSY381-Assoc Prof Hande Kaynak 10/10/2023 Differential Reinforcement of Other Behavior Differential Reinforcement of Other Behavior 17 18  The process of extinction can be greatly facilitated by both extinguishing the target behavior and reinforcing the occurrence of a replacement behavior.  Extinguishing the target behavior and reinforcing 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.  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. Differential Reinforcement of Other Behavior 19  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.  They are strong and effective because the target behavior is weakened both by the lack of reinforcement for that behavior and by the reinforcement of alternative behaviors that come to replace it.  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 20  The presence of a discriminative stimulus reliably affects the probability of the behavior. Why? Because it signals the availability of reinforcement, so it increases the probability that the behavior will occur. The rat learns to press the lever only in the presence of the tone!  DRO and DRI procedures are useful in that they tend to reduce many of the side effects associated with an ________ procedure. A behavior is said to be under s______ c_______ when it is highly likely to occur in the presence of a certain stimulus. 5 PSY381-Assoc Prof Hande Kaynak 10/10/2023 Stimulus Control Stimulus Generalization 21 22 Stimulus generalization is the tendency for an operant response to be emitted in the presence of a stimulus that is similar to an SD. with the SD italicized Stimulus discrimination, the tendency for an operant response to be emitted more in the presence of one stimulus than another. In the presence of an 1,800- or 2,200Hz tone, both of which are more similar to the original SD , than in the presence of a 1,200- or 2,800-Hz tone, which are less similar. The Peak Shift Effect 23 The Peak Shift Effect 24  A discriminative stimulus for extinction is typically given the symbol SΔ, signals the absence of reinforcement. The rat’s behavior of lever pressing is under strong stimulus control.  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. Discrimination training: Whenever the 2,000-Hz tone sounds, a lever press produces food; whenever the 1200Hz tone sounds, a lever press does not produce food. 6 PSY381-Assoc Prof Hande Kaynak The Peak Shift Effect 25  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 27 10/10/2023 The Peak Shift Effect 26  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. Multiple Schedules and Behavioral Contrast 28  If an orange key light is trained as an SD in a key pecking  Consists of two or more independent schedules presented 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. 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. 7 PSY381-Assoc Prof Hande Kaynak 10/10/2023 Multiple Schedules and Behavioral Contrast 29  Behavioral Contrast 30  Behavioral contrast occurs when a change in the rate of reinforcement on one component of a multiple schedule produces an opposite change in the rate of response on another component.  2 basic contrast effects: positive and negative.  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 reinforcement on one component results in an increase in rate of response on the other component. Behavioral Contrast  A negative contrast effect; 31  First  And then, VI 30-sec provides a higher rate of reinforcement.  With more reinforcement now available on the red key, the 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  A positive contrast effect; 32  First  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.  As one component becomes less attractive (changing from VI 60-sec to VI 120-sec), the unchanged component becomes relatively more attractive. 8 PSY381-Assoc Prof Hande Kaynak Behavioral Contrast 33  Positive contrast effect: The situation is analogous to the woman whose husband has become less caring and affectionate at home; as a result, she spends more time flirting with other men at work. The men at work seem relatively more attractive compared to the husband she has at home.  Negative contrast effect: The situation is analogous to a woman whose husband has suddenly become much more affectionate and caring at home; as a result, she spends less time flirting with other men at work. The men at work seem relatively less attractive compared to her husband at home. Behavioral Contrast 35 10/10/2023 Behavioral Contrast 34  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. 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. Behavioral Contrast 36  An additional type of contrast effect is anticipatory contrast.  e.g. If Jackie hears her mother say that it is getting close to 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. – upcoming change in the rate of reinforcement. 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. her bedtime, she is likely to become more involved in the computer game she is playing.  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. 9 PSY381-Assoc Prof Hande Kaynak 10/10/2023 Behavioral Contrast 37  Vronsky (another character in Tolstoy’s Anna Karenina) falls deeply in love with Anna, who is the wife of another man.  For several months, they carry on a passionate affair. When Anna, however, finally leaves her husband to be with him, Vronsky finds that he soon becomes bored with their relationship.  The fact that his feelings for Anna were much stronger when their relationship was more precarious is in keeping with the principle of __________ contrast. 10