Applied Behavior Analysis Positive & Negative Reinforcement Chapters 11 & 12 Questions from: Last class or Chapter 2? In-class quiz (20 minutes) ►Review quiz ►Review HW 1 ►Lecture ► ESSPED 5742 3 Objectives Define and provide examples of: Positive & negative reinforcement Motivating operations (MO), stimulus control, and discriminative stimuli (SDs) Define & provide examples of: Unconditioned and conditioned reinforcers (UR, CR) Describe methods to identify potential reinforcers Describe how to use reinforcement correctly Objectives Describe the differences between SDs and MOs Given a scenario, identify Motivating operations (MOs) Discriminative stimulus (SD) Whether it is an example of positive or negative reinforcement The potential function of behavior Review: Respondent Conditioning Antecedent A Stimulus Behavior B Response Before conditioning: • Unconditioned stimulus elicits the unconditioned response (e.g., meat powder elicits salivation) • Neutral stimulus elicits nothing Review: Respondent Conditioning During conditioning: • Unconditioned stimulus elicits the unconditioned response • Neutral stimulus paired with unconditioned stimulus elicits salivation (e.g., bell paired with food elicits salivation) After conditioning: • Unconditioned stimulus elicits unconditioned response • Conditioned stimulus (previously the neutral stimulus) elicits a conditioned response (i.e., salivation) Review: Operant Conditioning Antecedent A Stimulus • Evoked by antecedent stimuli Behavior Consequence B C Response Consequence • Maintained by consequence •Pos. +R = add stimulus & bx. •Neg. +R = remove aversive stimulus & bx. •Pos. +P = add stimulus & bx. •Neg. +P = remove stimulus & bx. Respondent Behavior is elicited by antecedent stimuli • Antecedent stimulus (US or CS) causes the response (UR or CR) Behavior is involuntary (i.e., reflexive) Eye blink Salivating Heart beating fast Typically involves action from autonomic nervous system • Association between involuntary response and stimulus • • • • A & B (2 term contingency) • S-->R Operant Behavior is evoked by antecedent stimuli • Antecedent stimulus changes probability of whether response will occur again Behavior is voluntary • • • • Throwing a ball Singing Eating Association between voluntary response and consequence A, B, & C (3 or 4 term contingency) • R-->S Behavior is maintained by its consequence Review: Keep in mind the following… We reinforce or punish the person’s behavior Correct: Alex is crying because in the past, his behavior has been reinforced Incorrect: Alex is crying because in the past he has been reinforced Respondent bx. is elicited & operant bx. is evoked Positive pleasant or good; Negative bad Positive = added to the environment Negative = removed from the environment Individual differences (i.e., items that function as reinforcers are idiosyncratic) No two people experience the world the same; different learning histories (i.e., history of reinforcement) Be aware of circular reasoning! Circular reasoning: To attribute cause of a behavior to a process or a thing (behavior is a symptom of some underlying condition) Circular reasoning DON’T Attribute cause of a behavior to a process or a thing (i.e., behavior is a symptom of some underlying condition) Why does Johnny leave his seat frequently? Because he leaves his seat frequently He has ADHD (condition) (symptom) How do you know he has ADHD? Circular reasoning • Why does Johnny leave his seat frequently? Thus, we are using cause to explain cause Because he leaves his seat frequently He has ADHD (condition) (symptom) • Circular reasoning adds nothing to S-R or R-S relationship How do you know he has ADHD? Why does Matt hit his head on the wall? Circular reasoning Because he hits his head on the wall He has Autism (condition) (symptom) How do you know he has Autism? Circular reasoning for Respondent Conditioning Don’t say that conditioned salivation or emotional responses occur because: The child expects to hear the loud noise when he sees the bunny The dog now knows of the tone-food relationship The child now knows of the bunny-loud noise relationship The dog now associates the tone with food The child now associates the bunny with the loud noise How can we discuss Respondent Conditioning? Describe the functional relationship between the IV & DV The child shows an emotional response (i.e., increased heart rate & breathing) when he sees a bunny because: When the bunny was paired with the loud noise, it acquired the eliciting properties of the loud noise The bunny functions as a conditioned stimulus (CS) & elicits an emotional response because it was paired in the past with the unconditioned stimulus (US) Brief review Negative reinforcement Function of behavior Negative reinforcement review Negative reinforcement: https://www.youtube.com/watch?v=Vb8xXp4y-nQ ASR: Neg. reinforcement Negative reinforcement example Daniel is on his way to school and sees a group of bullies en route. In the past, this group of bullies has taken his lunch money and tossed his book bag. As such, Daniel decides to take a different, yet longer, route to school. On subsequent days, Daniel continues to take the longer route to class. What is the antecedent? What is the behavior? What is the consequence? ASR: Neg. reinforcement Negative reinforcement example Daniel is on his way to school and sees a group of bullies en route. In the past, this group of bullies has taken his lunch money and tossed his book bag. As such, Daniel decides to take a different, yet longer, route to school. On subsequent days, Daniel continues to take the longer route to class. A = Bullies present B = Taking a different route C= Bullies no longer present Daniel effectively avoided the bullies by taking a different route The aversive stimulus (i.e., the bullies) were removed from Daniel’s presence when he decided to take a different path to class WTF??!! What's’ the function? Function 2 main functions: To access something desirable Function 2 main functions: To avoid something undesirable WTF??!! What's’ the function? http://www.youtube.com/embed/OxdtMVww2q0 ASR: What do you think may be the function of the child's behavior? Is the child’s behavior being: Positively reinforced Negatively reinforced Positively punished? Negatively punished? Is the mother’s behavior being: Positively reinforced Negatively reinforced Positively punished? Negatively punished? ASR: What do you think may be the function of the child's behavior? Access to tangibles Is the child’s behavior being: Positively reinforced Negatively reinforced Positively punished? Negatively punished? Is the mother’s behavior being: Positively reinforced Negatively reinforced Positively punished? Negatively punished? 1 New material Discriminative stimulus D (S ) & S-delta ∆ (S ) Discriminative Stimulus (SD ): A stimulus in the presence of which a response has been reinforced And in the absence of which a response has not been reinforced S-delta (S∆ ): A stimulus in the presence of which a response has not been reinforced SDs have to do with the availability of the reinforcer Let’s put this in context… Response: Hail a Taxi Get taxi Do not get taxi Let’s put this in context… Response: Hail a Taxi Get taxi Do not get taxi • Responses are reinforced in the presence of one stimulus • Responses are not reinforced in the presence of other stimuli Why does this occur?... Response: Hail a Taxi Get taxi Do not get taxi • Why does this occur? Because in the past hailing a taxi was reinforced only when the taxi was unoccupied (reinforcer was available) So… • The next time we need a taxi, we will only engage in hailing when we see an unoccupied cab • The unoccupied taxi becomes a Discriminative Stimulus (SD) for hailing taxi • The occupied taxi becomes S-delta (S∆) (reinforcer is not available) Remember… In order for a stimulus to be called an SD : There must be history of differential reinforcement: The behavior was reinforced in the presence of the stimulus • And not reinforced in its absence • Effects on behavior: (SD) • for reinforcement Has an evocative effect on the response S-delta • (SΔ) for reinforcement Has an abative effect on the response Question In the previous example, an individual was standing in the rain and hailed a taxi. A week later, as soon as it looked like it was going to rain, she immediately looked for a free taxi. Is this an example of: a) b) c) d) e) Positive reinforcement Negative reinforcement Positive Punishment Negative Punishment Not enough info A B C D E Example SD Teacher gives child toy SD: Child wants access to a specific toy Teacher Marie Behavior: Scream SΔ : Teacher Jen Teacher does NOT give child toy Marie reinforced crying by giving access to the toy Example SD SD: Teacher Marie In the future, the child is more likely to cry to get access to the toy in the presence of Marie and not in the Behavior: presence of Jen Scream Child wants access to a specific toy SΔ : Teacher Jen Jen did not reinforce the behavior; therefore, the child is less likely to cry for access in her presence Another example SD: Reinforcer: Teacher Marie Break from work Response: Scream SΔ: Teacher Melissa No break from work In the future, the child is more likely to cry to get out of working in the presence of Marie and not in the presence of Jen D S (Summary) Answers the question: How do we learn to emit certain behaviors at specific times but not at other times? SD = a stimulus change that occurs before the behavior Stimulus change evokes behavior or sets the occasion for behavior to occur SDs have to do with the availability of a reinforcer (i.e., has the reinforcer been delivered in the presence of that stimulus in the past?) Responses that occur in the presence of the SD are reinforced Responses that occur in the presence of the S-delta are not reinforced or receive a lesser quality reinforcer Stimulus Control A response occurs more frequently in the presence of one stimulus than in the presence of another Behavior: Screaming Scream in the presence of Teacher Marie and not in the presence of Teacher Melissa Therefore, screaming is under the stimulus control of teacher Marie Stimulus control Stimulus control: The tendency for should the targetbe behavior occur in the presence Stopping your car undertothe stimulus control of the of the SD, but not in the presence of the SΔ red light • E.g. If you are a good driver… then you will discriminate between red lights and green lights! Driving through an intersection should be under the stimulus control of a green light Remember… In order for a stimulus to be called an SD : There must be history of differential reinforcement: The behavior was reinforced in the presence of the stimulus • And not reinforced in its absence • Effects on behavior: (SD) • for reinforcement Has evocative effect on the response S-delta • (SΔ) for reinforcement Has abative effect on the response Example: Development of stimulus control What is 4 x 2? 8 Yes! It is 8 Example: Development of stimulus control What is 4 x 2? 10 No. That is incorrect Stimulus control When a child’s behavior comes under the control of the SD : We say the SD has acquired stimulus control over the child’s behavior Stimulus control When a child’s behavior comes under the control of the SD : We say the SD has acquired stimulus control over the child’s behavior Example: The vocal verbal stimulus (what is 4 x 2) gains stimulus control over the response “8” Circular reasoning for Operant Conditioning Don’t say that the antecedent stimulus (SD): Informs the organism of the availability of a reinforcer Don’t say the child: the antecedent stimulus (SD) with the reinfrocer Expects to get a reinfrocer when he sees the SD Knows that the reinfrocer is available Thinks that he or she will get reinforced Figured out that when the SD is present he or she can get reinforced Associates How can we discuss Operant Conditioning? The presence of teacher Marie sets the occasion for the response to be reinforced The teacher provides an opportunity for the behavior to access the reinforcer The teacher evokes a response that has been reinforced in the past The child learned to cry in the presence of teacher Marie because in the past crying was reinforced by that teacher ASR The following sentence is correct, True or False: The child engages in that behavior because he knows his behavior will be reinforced or ASR The following is an example of circular reasoning, True or False: The child engages in that behavior because in the past his behavior has been reinforced in the presence of mom or ASR True or False: SDs have to do with the availability of the reinforcer? or Questions? Motivating operations (MO) https://www.youtube.com/watch?v=r79tq-gCxKk Child is deprived of attention Behavior: SD:Mom Scream Example MO Mom gives child attention Motivating operations The thing that is “wanted” will function as a reinforcer at that moment in time AND At that moment, behavior that has been previously reinforced with that thing are more likely to occur Motivating operations MOs have two parts: 1. Increase the reinforcing or punishing value of an object, stimulus, or event (value altering effect) Has to do with the effectiveness of a reinforcer or punisher (e.g., Is the “reinforcer” reinforcing at that moment in time?) 2. Evoke or abate behaviors that have been reinforced or have accessed object, stimulus, or event in the past Evokes or abates the current frequency of behavior not future frequency 2 Types of MOs Establishing Operations: Increases the reinforcing effectiveness of a consequence Increases the current frequency of the behavior to access that consequence MO • Establishing Operation (EO) Effect • ↑ Reinforcing effectiveness • ↑ Behavior (Evokes behavior) 2 Types of MOs Establishing Operations: Increases the reinforcing effectiveness of a consequence Increases the current frequency of the behavior to access that consequence MO Effect • Establishing Operation (EO) • ↑ Reinforcing effectiveness • ↑ Behavior (Evokes behavior) • Abolishing Operation (AO) • ↓ Reinforcing effectiveness • ↓ Behavior (Abates behavior) Abolishing Operations: Decreases the reinforcing effectiveness of a consequence Decreases the current frequency of the behavior to access that consequence What variables determine if we want something or not? Deprivation: Lacking the reinforcer Any behavior that accessed the reinforcer in the past will be emitted at the first opportunity Satiation: Consuming or accessing a substantial amount of a reinforcer Temporarily reduces responding even when the reinforcer is freely available Example MO Child wants access to a specific toy SD: Teacher Marie Behavior: Ask for toy Teacher gives child toy Example MO The child wants a toy (MO): This makes the toy a more effective reinforcer AND Evokes behaviors that have lead to accessing that toy in the past Example MO Child wants access to a specific toy SD: Teacher Melissa Behavior: Cry Teacher gives child toy MO vs. SD • How are they similar? They both precede behavior They both evoke operant behavior (but for very different reasons) • How do they differ? SDs have to do with the availability of a reinforcer (Has the reinforcer been delivered in the presence of that object in the past?) MOs have to do with the effectiveness of a reinforcer (Is the “reinforcer” reinforcing at that moment in time?) Changes the value of the consequence (e.g., the reinforcer) MO vs. SD In short: MOs change how much people want something SDs change their chances of getting it (Carbon et al., 2007 pg. 665) Ask yourself: • Is this antecedent event making the reinforcer more available? OR Is it making the reinforcer more valuable MOs and SDs MO: Good sleep the night before & breakfast SD: “Who can count to 10 for me?” Response: Correct Answer Yes! Well done! 66 MOs and SDs MO: Good sleep the night before & breakfast MO: No sleep, no money for breakfast SD: “Who can count to 10 for me?” Response: Correct Answer SD: “Who can count to 10 for me?” Response: Incorrect Answer Yes! Well done! Let’s try someone else. 67 Motivating Operations (MO) For Positive +R You have been working all day and did not have a chance to eat. On the way home, you see a sign for the TGIF restaurant. In the past, going into TGIF has always been reinforced with getting food. You pull into the parking lot and walk into the restaurant. In regards to pulling into the parking lot Food deprivation is: An EO The sign for TGIF is: An SD Contingency diagram for the prior scenario Immediate Antecedent Food deprivation (EO) TGIF sign (SD) Walk into the restaurant (Behavior) Sit down to order food (Consequence) Motivating Operations (MO) For Positive +R You had a large meal at TGIF. On the way home, you see a sign for the Cheesecake Factory, which is your favorite place to eat. In the past, going into Cheesecake Factory has always been reinforced with getting food. You look at the sign and continue driving home. In regards to eating at Cheesecake Factory Large meal at TGIF is: An AO The sign for Cheesecake Factory is: An SD Contingency diagram for the prior scenario Antecedent Eating food (being satiated) abolishes food as a Cheesecake reinforcer! Drive past Driving without Satiation AO sign (SD) restaurant (Behavior) getting food (Consequence) Food is available, but is only reinforcing when he/she is food deprived MOs and SDs Is the sign for the Cheesecake Factory making the reinforcer more available or more valuable? More available: • Just because you see a sign for the restaurant, it does not mean that you will stop to eat at the restaurant • If you are full after a large meal (satiated), you are less likely to go to the restaurant • Thus, the reinforcer is not more valuable in the presence of the restaurant it is just more available MOs and SDs Does lack of food make the reinforcer more available or more valuable? More Valuable: • You are deprived of food; therefore, food is a more effective reinforcer • Just because you are deprived of food, however, does not mean that food is more available • Thus the reinforcer is not more available when you are deprived of food but it is more valuable & will evoke behaviors that lead to food in the past Availability vs Motivation For Reinforcement Elopement maintained by attention Elopes when with dad but not when with mom Available SD Dad Not Available SΔ Mom Valuable EO Likelihood Of Elopement? High Likelihood Of Elopement? Low Not Valuable AO Likelihood Of Elopement? Very low Likelihood Of Elopement? Almost 0 Deprived of Attention Had a lot of Attention Availability vs Motivation For Reinforcement Elopement maintained by attention Elopes when with dad but not when with mom A B Dad Elopement Mom Elopement C Attention Deprived of Attention NO Attention Motivating Operations Unconditioned MO (UMO) Unlearned stimulus condition with value altering effect (alters the value of the consequence) Unconditioned EO (UEO) o Food deprivation o Water deprivation o Sleep deprivation o Activity deprivation o Oxygen deprivation o Sex deprivation o Being too warm o Being too cold o Increase in painful stimulation or discomfort o Effects of some drugs • Unconditioned AO (UAO) o Opposite of UEOs (ingestion or engaging in a specific activity) Conditioned MO (CMO) Learned stimulus condition with value and behavior altering effect Surrogate CMO (CMO-S) Reflexive CMO (CMO-R) Transitive CMO (CMO-T) ASR Provide one example of a motivating operation (list the four term contingency): Motivating operation Discriminative stimulus Behavior Consequence ASR True or False: Food deprivation is an AO? or ASR True or False: Being too hot is an EO? or ASR An SD means that the consequence is more: a) b) c) d) Reinforcing Punishing Available Potent Positive Reinforcement Types of reinforcers Unconditioned reinforcers (Primary reinforcer) Unlearned stimuli that increase the probability of a response Biological importance • Do not require learning • Examples: air, food, water, sleep, warmth, etc. • Types of reinforcers Conditioned reinforcers (Secondary reinforcers ) Neutral stimuli with no biological importance Repeatedly paired with Unconditioned reinforcer (UR) or conditioned reinforcer (CR) acquires capacity to increase responses • Examples: Praise, smile, toys, etc. • Types of reinforcers Generalized conditioned reinforcers Neutral stimuli with no biological importance Repeatedly paired with Unconditioned reinforcer (UR) or conditioned reinforcer (CR) acquires capacity to increase responses • Less likely subjected to the same effects of satiation & deprivation (EO does not need to be in effect for the stimulus to function as a reinforcer) • Examples: Money, attention, tokens, points, etc. • Types of reinforcers Edible Tangible Activity Social Edible = food Tangible = toys, stickers, TV Activities = playing a board game, leisure reading, listening to music Social = hugs, pat on back, praise Factors that affect reinforcers Motivating operations: Temporarily alter the effectiveness of a reinforcer & alter the current frequency of behavior that lead to obtaining the reinforcer in the past Deprivation vs. Satiation • Most reinforcers will not be effective unless the individual has been deprived of them for some period of time prior to their use (establishing operations vs. abolishing operations) o Above, however, does not pertain to generalized conditioned reinforcers Factors that affect reinforcers Reinforcer Size: The size (or amount or magnitude) of a reinforcer is an important determinant of its effectiveness Sufficient to strengthen the response, but not enough to satiate Factors that affect reinforcers Reinforcer presented contingently: The delivery of the reinforcer should depend on the occurrence of a specific behavior you are targeting Factors that affect reinforcers cont. Reinforcer Immediacy: For maximum effectiveness, a reinforcer should be given immediately after the desired response • The longer the delay between the behavior and the reinforcer, the less impact the reinforcer will have on the behavior Factors that affect reinforcers cont. Reinforcer Immediacy: For maximum effectiveness, a reinforcer should be given immediately after the desired response • The longer the delay between the behavior and the reinforcer, the less impact the reinforcer will have on the behavior o Other behaviors may occur during the delay o So, you will be strengthening the response of those OTHER behaviors! Factors that affect reinforcers cont. Reinforcer Immediacy: Remember: The behavior temporally closest to the For maximum effectiveness, a reinforcer should be given immediately after presentation of the reinforcer will be strengthened! the desired response • The longer the delay between the behavior and the reinforcer, the less impact the reinforcer will have on the behavior o o Other behaviors may occur during the delay So, you will be strengthening the response of those OTHER behaviors! Methods of identifying potential reinforcers Ask about preferences Methods of identifying potential reinforcers Ask about preferences Methods of identifying potential reinforcers Ask about preferences Free operant observation Methods of identifying potential reinforcers Ask about preferences Free operant observation Many variations of trial-based methods Effective Application of Positive Reinforcement 1. Select the behavior to be increased: The target behavior should be a specific behavior rather than a general category 2. Select reinforcers that (if possible): Are readily available Can be presented immediately following the desired behavior Can be used over and over again without causing rapid satiation Effective Application of Positive Reinforcement 3. Initially set achievable criterion to contact reinforcement 4. Provide a sufficient magnitude & quality of the reinforcer 5. Vary reinforcers to prevent satiation 6. Ensure the student can explain the reinforcement contingency Effective Application of Positive Reinforcement 7. Reinforce every “correct’ response initially (continuous schedule of reinforcement) Eventually weeks) you will thin the schedule (we will cover this in a few Effective Application of Positive Reinforcement 7. Reinforce every “correct’ response initially (continuous schedule of reinforcement) Eventually weeks) you will thin the schedule (we will cover this in a few 8. Gradually shift from contrived to naturally occurring reinforcers (e.g, social reinforcers instead of food) Reinforcement vs. bribery Reinforcement • Reinforcer is delivered contingent on the target behavior E.g., (child sitting in classroom teacher approaches) “If you finish ten problems on this worksheet, you can access five minutes of computer time.” Bribery • Something the child “wants” is delivered before the target behavior E.g., “If you promise to be good during our trip to the grocery, I will give you a cookie now” Something the child “wants” only comes available when he/she starts to misbehave E.g., (Child is fighting with sister and mom comes over) “If you stop fighting with your sister, we will go to your favorite restaurant now Reinforcement vs. bribery Reinforcement Bribery • Something the child “wants” is is delivered contingent Main a reinforcer: delivered before the target on the difference: target behaviorWhen delivering • Reinforcer behavior sitting in classroom teacherof time • E.g., You(child communicate ahead (i.e., BEFORE the E.g., “If you promise to be good during our trip approaches) “If you finish ten problems to the grocery, I will give you a cookie now” bad behavior occurs) what behaviors will and will not on this worksheet, you can access five minutes of computer time.” • Something the child “wants” access a reinforcer only comes available when he/she starts to misbehave E.g., (Child is fighting with sister and mom comes over) “If you stop fighting with your sister, we will go to your favorite restaurant now ASR: Let’s practice Danny sees his favorite toy (a fire truck) locked in the cabinet; however, he cannot access the toy by himself. In the past, when Danny asked the teacher to open the door to access the truck, the teacher opened the door. However, when Danny asked a peer to open the door, he/she never complied with the request. Based on the scenario above, what is the MO? a) The presence of the teacher b) The presence of the peer c) Seeing the cabinet d) Seeing the toy truck behind the locked cabinet ASR: Let’s practice Danny sees his favorite toy (a fire truck) locked in the cabinet; however, he cannot access the toy by himself. In the past, when Danny asked the teacher to open the door to access the truck, the teacher opened the door. However, when Danny asked a peer to open the door, he/she never complied with the request. Based on the scenario above, what is the SD? a) The presence of b) The presence of c) The presence of d) The presence of the teacher the peer the cabinet the toy ASR: Let’s practice Danny sees his favorite toy (a fire truck) locked in the cabinet; however, he cannot access the toy by himself. In the past, when Danny asked the teacher to open the door to access the truck, the teacher opened the door. However, when Danny asked a peer to open the door, he/she never complied with the request. Based on the scenario above, what is the S-delta? a) The presence of b) The presence of c) The presence of d) The presence of the teacher the peer the cabinet the toy ASR: Let’s practice Danny sees his favorite toy (a fire truck) locked in the cabinet; however, he cannot access the toy by himself. In the past, when Danny asked the teacher to open the door to access the truck, the teacher opened the door. However, when Danny asked a peer to open the door, he/she never complied with the request. Based on the scenario above, what is the behavior? a) Asking to open the door b) Asking to play with a toy c) Opening the door d) The presence of the cabinet ASR: Let’s practice Danny sees his favorite toy (a fire truck) locked in the cabinet; however, he cannot access the toy by himself. In the past, when Danny asked the teacher to open the door to access the truck, the teacher opened the door. However, when Danny asked a peer to open the door, he/she never complied with the request. Based on the scenario above, what is the reinforcer? a) The teacher b) The peer c) Access to the toy d) A closed door ASR: Let’s practice Danny sees his favorite toy (a fire truck) locked in the cabinet; however, he cannot access the toy by himself. In the past, when Danny asked the teacher to open the door to access the truck, the teacher opened the door. MO Sight of fire truck locked in cabinet SD Reinforcer: Teacher Door is opened (access to toy) Response “Open door” S-delta Peer Door is not opened (no access to toy) ASR: Let’s practice True or False: Motivating operations alter the reinforcing effectiveness of the consequence & increase future behaviors that have resulted in accessing that consequence in the past? ASR: Let’s practice Yes or No: It is correct to say: The dog now associates the bell with food? Negative Reinforcement The removal or decrease in intensity of a stimulus contingent on a response that increases the future frequency of that response Both positive and negative reinforcement produce an increase in responding BUT The type of stimulus change that follows the behavior differs: Negative reinforcement = Terminates a stimulus (usually aversive) that was present prior to responding Positive reinforcement = Produces a stimulus change that was absent prior to responding Positive reinforcement: EO SD Response SR+ Absence of food for 3 hours Teacher says “Snack time” and crackers are on table “Crackers, please” Crackers presented Saying “Crackers, please” when it is snack time and when crackers are present is more likely to occur in the future Negative reinforcement: EO SD Response SR- Math worksheet with 20 problems on student’s desk Teacher says “Complete 5 problems, then you don’t have to do the rest” Completes 5 problems Remaining problems on worksheet removed Completing math problems when the math worksheet is present and when the teacher gives instructions is more likely to occur in the future Negative Reinforcement Escape contingency: A response terminates an ongoing (usually aversive) stimulus For an escape contingency, four events must occur: Antecedent in the presence of which escape would be reinforcing The SD is another antecedent event in the presence of which escape is more likely to be reinforced The response is the act that produces the reinforcement The reinforcer is termination of the event that served as the EO Escape Contingency Escape Contingency In an escape contingency, the stimulus is already present (e.g., you are in car and it is snowing) and EO you are “escaping” from the aversive stimulus S Hate snow D In car and see it is snowing outside SR- Response Drive slowly Escape getting into an accident Driving slowly is more likely to occur in the future when you see that it is snowing outside Negative Reinforcement Escape contingency: A response terminates an ongoing (usually aversive) stimulus Antecedent in the presence of which escape would be reinforcing The SD is another antecedent event in the presence of which escape is more likely to be reinforced The response is the act that produces the reinforcement The reinforcer is the event that served as the EO Avoidance contingency: A response that postpones or prevents the presentation of a stimulus (usually aversive) Avoidance Contingency Avoidance Contingency In EO an avoidanceD contingency, the stimulus is not yet present S Hate snow SR(e.g., not yet driving), & you Response are “avoiding or postponing” Look out Avoid any the presentation of an aversive stimulus window to Do not leave house see it is snowing potential accident Staying home when it is more likely to occur in the future when you see that it is snowing outside Negative Reinforcement vs. Punishment Both involve “aversive” events In negative reinforcement: The aversive stimulus is present prior to the target behavior Removal of the aversive stimulus produces an increase in the future frequency of responding In punishment: The aversive stimulus is presented contingent on the target behavior The presentation of the aversive stimulus produces a decrease in the future frequency of responding Class activity Break into two groups Answer the questions on the worksheet After 10 minutes elapses, I will call on each group to give an answer to 1 of the scenarios After-class tasks ► Reading assignment Chapter 11(257-265, 285-289) Chapter 12 (292-295) Don’t Shoot the Dog (1-15) References Cooper, J. O., Heron, T. E., & Heward, W. L. (2007). Applied behavior analysis (2nd ed.). Upper Saddle River, NJ: Prentice Hall Kazemi, E., Adzhyan, P., & Fahmie, T. Applied Behavior Analysis Introduction (lecture notes). 12/2012 Malott, R.W. (2008). Principles of behavior (6th ed.). Upper Saddle River, New Jersey: Pearson Prentice Hall. Michael, J. L. (2004). Concepts and principles of behavior analysis. Kalamazoo, MI: ABAI Skinner, B. F. (1953). Science and human behavior. New York: MacMillan