Ch. 14 Extension Interval Schedules

Ch. 14 Extension Interval Schedules - Chapter 14 Interval...

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Unformatted text preview: Chapter 14 Interval Schedules of Reinforcement: Time Dependent Ratio Strain “Requiring so many responses for a reinforcer that the behavior slows or even totally stops.” The opposite of ratio strain is Resistance to Extinction The degree that a response will continue to occur when it is no longer reinforced Which schedule would be more/most resistant Which to extinction?: CRF versus FR: 5 FR: 12 versus FR: 6 VR:3 versus VR: 15 VR:5 versus FR: 5 VR:5, FR: 5, FR: 15, VR: 15 FR: 5 FR: 12 VR: 15 VR: 5 VR: 15 Resistance to Extinction The degree that a response will continue to occur The when it is no longer reinforced when Which schedule would be less/least Which resistant to extinction?: resistant CRF versus FR: 5 CRF FR: 12 versus FR: 6 VR:3 versus VR: 15 VR:5 versus FR: 5 VR:5, FR: 5, FR: 15, VR: 15 CRF FR: 6 VR: 3 FR: 5 FR: 5 Interval Schedule “A schedule for reinforcing the first response after a period of time from the prior reinforcement.” Interval schedules: Reinforcement becomes available after a period of time: time: 1) 2) Fixed (specific) period of time Variable period of time Interval Schedules: Fixed Interval: Fixed Variable Interval: “A schedule for reinforcing the first response after a fixed period of time from the prior reinforcement.” “A schedule for reinforcing the first response after a variable period of time from the prior reinforcement.” Fixed Interval Schedules The first response to occur after a fixed first after fixed period of time is reinforced. period • This means that no matter how many times one responds during the time period there is no reinforcer during no presented. presented. • Responding during the time period does not make receiving the reinforcer any more likely. receiving • If there is never a response, no reinforcer is presented. If • Only first response to occur after the fixed time period is reinforced. is Fixed Interval Schedule Fixed Interval Example : (The first response to occur after a fixed (The first fixed period of time is reinforced.) period The first time I turn on my television to the CW channel after 8 p.m. on Thursday I see a new episode of “Smallville.” No matter how many times I turn the TV on before 8 p.m. I do not see a new episode. The response is turning on TV and looking at it, the reinforcer is seeing a new episode. I had to respond or I saw no new show. Interval Schedule Fixed Interval Example 2: You have a food card for the HUB and you want eat You scrambled eggs which are only available during breakfast. The HUB serves eggs from 7-9 a.m. This is an example of an FI:24 hour. Why? FI:24 Why? What is the fixed time period? What fixed What is the response? What response What is the reinforcer? What reinforcer Opens every 24 hours Going into the HUB Eating scrambled eggs What responses are reinforced? What responses are not reinforced? Only 1st R after 7a.m. Any Rs before 7 a.m. Fixed Interval Schedules: Pattern of Responding Pattern: There is 1) little or no responding at the beginning of the interval; 2) responding gradually increases until the highest rate of responding occurs at the end of the interval. This same pattern repeats after reinforcement. This pattern is called a “fixed repeats interval scallop.” The number of responses is The shown on the ordinate (yordinate axis) and time is on the axis) abscissa (x-axis). The abscissa diagonal hatch marks indicate the presentation of reinforcement. reinforcement. Variable Interval Schedules The first response to occur after a first after variable period of time is reinforced. variable • This means that no matter how many times one responds during the time period there is no reinforcer during presented. presented. • Responding during the time period does not make receiving the reinforcer any more likely. receiving • If there is never a response, no reinforcer is presented. presented. • Only the first response to occur after the variable time period is reinforced Variable Interval Schedule Variable Interval Example #1: (The first response to occur after a variable (The first period of time is reinforced.) period You want to get some advice from your advisor, You but he does not have regular office hours. No matter how many times you try to see him, if he is not in his office you don’t get to talk to him. The first time to go to his office (R) and he is The and there you get to talk to him (Sr+). However, the there ). advisor is in his office at variable and variable unpredictable times. unpredictable Variable Interval Schedule Variable Interval Example 2: (The first response to occur after a variable (The first variable period of time is reinforced.) period Manuel is working hard outside a home with an open Manuel window. When the wind blows just so the curtain moves so he sees the silhouette of a beautiful woman (statue). No matter how many times Manuel looks, if the wind has not blown the curtain away, he sees no beautiful woman. The first time he looks up (R) after the curtain is blown away first after he sees the beautiful woman (Sr+). However, the he ). opportunity to see the beautiful woman varies and is varies unpredictable. unpredictable. Variable Interval Schedules: Pattern of Responding Pattern: Usually, there are steady consistent rates of responding. Typically, there is a little or no pausing little immediately following reinforcement. immediately The number of responses The is shown on the ordinate (y-axis) and time is on the abscissa (x-axis). abscissa The diagonal hatch marks indicate the presentation of reinforcement. reinforcement. Patterns of Behavior under the Four Schedules of Reinforcement Overall which schedule generates the Overall highest rates of responding? highest Patterns of Behavior under the Four Schedules of Reinforcement FI: Slope near FI: horizontal horizontal Overall which schedule generates the Overall lowest rates of responding? lowest Patterns of Behavior under the Four Schedules of Reinforcement FR: Steepest Slope and PRP and Which schedule generates high rates of Which responding and post reinforcement pauses? responding Patterns of Behavior under the Four Schedules of Reinforcement VR and VI Overall which schedules generate the Overall steadiest rates of responding? steadiest Limited Hold a. b. c. Definition: Limited Hold is 1) a time period in which the response in must occur 2) to be reinforced. must Example 1: You have 15 weeks in which to complete your research which project to earn a grade. project Example 2: Students who complete 15 math problems within 50 minutes gets extra recess. 50 Limited Hold A limited hold can be used with any limited schedule of reinforcement: FR, VR, FI, VI FR, In going to breakfast at the HUB (FI: In 24 hour), the student has to go to the HUB after 7 a.m. (24 hours), BUT the after student has to also respond within a two-hour limited hold to get breakfast (7 - 9 a.m.) Limited Hold Here is a tricky example: Here A teacher tells her students that each student who completes 12 problems correctly within 45 minutes will earn an extra 10 minutes of recess. extra What is the schedule of reinforcement? FR: 12 Is there a limited hold? What is it? 45 minutes in which to respond to earn Sr+ Deadline ≠ FI Schedule In an FI schedule the response results in Sr+ In when it occurs after a fixed time. In a deadline the response results in the Sr+ In if the response occurs during the fixed time. In the previous example, the students had 45 minutes in which to complete the 12 problems to get 10 extra minutes of recess. problems This was a deadline. This Superstitious Behavior Superstitious Behavior is behavior which is accidentally reinforced is (the presentation of the reinforcer was not (the not contingent upon the “superstitious behavior,” but because the behavior occurred when the reinforcer was presented, the behavior occurs more often in the future) in Skinner Generated Superstitious Behavior Each pigeon was in a cage. Every 15 Each seconds there was a click and grain would be presented regardless of behavior: The presentation of the reinforcer was not The contingent upon behavior, but each bird responded in some way when the reinforcer was presented, that behavior then occurred more often in the future) then Skinner Generating Superstitious Behavior The behavior that occurerd at the end of 15 The min. was reinforced, though in fact the behavior had nothing to do with the presentation of the reinforcer. That behavior was more likely to occur again and be the behavior that was occurring when the next reinforcer was delivered in 15 seconds, and so on; thus, developing Superstitious Behavior Skinner Generating Superstitious Behavior Each bird developed quite different Each “superstitious behavior” “superstitious One bopped its head up and down One One trotted in figure 8s One One leaned to the left, then to the right One The reinforcer was not contingent upon The not these responses. The food was delivered every 15 seconds - no response required Another example of Superstitious Behavior About 10 years ago, my husband was teaching this About class on Wednesday evening. He mentioned that the shirt he was wearing was his “lucky” shirt. He happened to wear it when he shot low golf rounds and high bowling scores, so when he had an important match or tournament he would wear this shirt. When class was over he went to his very competitive bowling league and . . . competitive he bowled a perfect 300 game! he Your own example of Superstitious Behavior (continued) Did my husband’s wearing his lucky Did shirt cause him to bowl a 300? shirt What do you think will happen to the What future probability of his wearing his “lucky” shirt for important matches? “lucky” What is your own example of What superstitious behavior? FI 15-Minute Example: About 10 years ago a friend had a ruptured colon. When I About visited him in the hospital he held a cord with a button on it. He pressed the button once in a while, then more and more frequently until a chime sounded. He was self-administering morphine. The first time he pressed the button after 15 minutes resulted in his getting morphine via his IV. No responses during the 15 minutes had any effect. responses What is the fixed time period? What fixed What is the response? What response What is the reinforcer? What reinforcer 15 minutes Pressing the button Reduction in pain/chime What responses were reinforced? Only 1st R after 15 minutes What responses were not reinforced? Any Rs during 15 minutes Questions about various schedules: Questions FR VR FI VI What schedule(s) generate steady consistent rates of responding? What VR and VI VR What schedule(s) the lowest rate of responding? What FI FI What schedule(s) results in the highest rates of responding with post What reinforcement pauses? reinforcement FR What is the minimum number of responses that could lead to S r+ for for the following schedules? the FR:8 VR:8 FI:8min VI:8min (8 Rs) (1R) (1R) (1R) ...
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This note was uploaded on 10/20/2011 for the course EDU 300 taught by Professor Smith during the Spring '09 term at BYU.

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