Chapter 10 – Aversive Control: Avoidance and Punishment

1. Chapter 10 – Aversive Control: Avoidance and Punishment • Outline • Active Avoidance vs. Passive Avoidance • Negative Reinforcement vs. Positive Punishment • Avoidance • Origins of the Study of Avoidance • Discriminated Avoidance (Signaled Avoidance) • Mowrer’s Two-Factor Theory of Avoidance • Experimental Analysis of Avoidance Behavior • Acquired Drive Experiements • Extinction of Avoidance • Nondiscriminated (Free-Operant) Avoidance • Punishment • What is Punishing? • Is Punishment Effective? • Rules of Punishment

2. Avoidance procedures increase the occurrence of instrumental behavior • Active avoidance • Negative Reinforcement (Escape or Avoidance) • Learn to make a response to avoid a negative outcome • Punishment procedures suppress instrumental responding • Passive avoidance • Positive Punishment • Learn to withhold responding to avoid a negative outcome.

3. Origins of the study of avoidance • Vladimir Becherev (1913) • Participants were asked to put their finger on a metal plate. • tone (CS) was followed by a shock (US) through the metal plate • Participants quickly learned to pick up their finger (CR) when they heard the tone (CS). • This was considered to be a standard example of classical conditioning. • But it was different • Removing finger cancelled the US • avoidance

4. Brogden, Lipman, and Culler (1938) • Directly compared classical conditioning to avoidance learning • Guinea pigs in a running wheel. • CS- tone • US – shock • The shock stimulated the guinea pigs to run (UR) • Gp1 Gp2 • Classical Avoidance • US always followed US followed the tone the tone unless the Guinea’s ran • The Avoidance group ran much more than the classically conditioned animals.

7. Discriminated Avoidance procedure (signaled avoidance procedure) • There is a warning stimulus (CS) • What happens after the CS depends upon what the animal does. • Escape Trial • Don’t respond fast enough • US is presented until response is made • Successful Avoidance Trial • Respond quickly enough • CS is turned off and there is no US on that trial.

9. During early training most trials are escape trials • eventually the animals learn to make the avoidance response, and then avoidance behaviors take over. • These experiments have often been performed in shuttle boxes.

11. Shuttle avoidance • Two-way • move back and forth. • One-way • always start each trial on one side • move to the other.

12. Mowrer’s two factor theory of Avoidance. • The problem for avoidance tasks is that once animals are performing well, the outcome (shock) doesn’t occur anymore • Looks like extinction • So what motivates responding? • Pavlovian (emotional conditioning) • Signaled • CS – US • Instrumental  • After fear is conditioned the second thing that is learned is the instrumental response (jump barrier). • What motivates responding? • Negative RF • escape from conditioned fear.  

13. Experimental Analysis of Avoidance Behavior • Acquired drive experiments • In the typical avoidance procedure the classical conditioning, and instrumental conditioning, occur simultaneously. • But if two-factor theory is correct it should be possible to train these two kinds of learning separately. • 1) condition fear to a CS with a pure classical conditioning procedure. • CS (tone) --> US (shock)   • CR (fear) • 2) the animals are periodically presented with the CS, but an instrumental response can prevent it. • No shocks are delivered in phase 2.

14. Brown and Jacobs (1949). • Classical conditioning • Confined rats in one side of a shuttle box – the shuttle opening was blocked.  • Light/tone (CS) --> shock (US). • 22 trials. • Instrumental conditioning • The shuttle box opening was opened.  • CS came on, and remained on until the rats went to the other side – escape. • The animal was removed until the next trial. • Over time the shock conditioned animals learned to cross over to the other side sooner after the initiation of the CS. • Do we need a control group?

15. Extinction of Avoidance? • Solomon, Kamin, and Wynne (1953) • One dog avoided shock for 650 straight trials after escaping a few. • Is it possible to extinguish? • Flooding or Response Prevention • Participant is prevented from making the instrumental response during CS • The US is omitted (extinction) • Block off door to shuttle box • CS alone • Has clinical implications • Help people extinguish pathological avoidance • Learn to avoid anxiety producing situations.

16. Nondiscriminated (Free-Operant) Avoidance • Executive Monkey • Press key every 15 seconds to avoid shock. • S-S interval – time between shocks if you don’t respond • R-S interval – period of safety created if you do respond • Don’t have to be the same. • S-S 8s • R-S 15s. • you will receive a shock every 8s unless you respond. • If you do respond you buy yourself 15s in the absence of shock.

17. Chimps have been trained with several schedules to keep track of to avoid shock (Koestler & Barker, 1965). • respond every 5-s on a button to avoid shock (Free operant avoidance) • any key that lit up with a light (Sd) had to be pressed within one second or they would be shocked (Signaled Avoidance). • a separate unlit key had depressed within one second of a second Sd ( a tone; Signaled Avoidance) • The Chimps were able to keep track of all of this at once • motivated by fear?

18. So Fear motivates responding? • Kamin, Brimer, and Black ran an experiment that showed that this may not be the case. • Conditioned Suppression • Phase 1 • Rats trained to barpress for food • Phase 2 • Then put into a shuttle box where a tone Sd set the occasion to jump the barrier to avoid shock • There were four groups (they differ in amount of training) • group 1 = avoid shock by jumping barrier on 1 trial • group2 = avoid shock by jumping barrier on 3 consecutive trials • group 3 = avoid shock by jumping barrier on 9 consecutive trials • group 4 = avoid shock by jumping barrier on 27 consecutive trials • Test • returned to the operant chamber • continued to barpress for food. • The tone was sounded

19. Rats that had reached the 1, 3, or 9 consecutive trial criterion, showed considerable suppression when the tone sounded. • Fear tone. • surprisingly the rats that had had 27 consecutive trials of avoidance did not suppress responding. • It seems that increasing experience with the situation lessens the fear. • especially because the animals have learned they have control over the situation. • Think of an air traffic controller. • are they motivated by negative reinforcement? • are they afraid all of the time? • are they only afraid when they think they have made a mistake?  • Nevertheless Two- Factor theory is the theory of avoidance against which all others are compared.

20. Punishment • As we have already discussed. Punishment is some manipulation that causes a decrease in responding  • As a society we tend to be very interested in punishment • Crime • Children • Is Punishment effective? • Skinner initially argued that Punishment was not very effective • Possibly came to this conclusion because he was using weak punishers • Electronic slap of the paw • It has been shown that punishment can be effective if the correct conditions are met • Domjan’s example • Ticket for speeding • Child sticks fork in electric socket.

21. Experimental Analysis of Punishment • Punishment involves decreasing a behavior • in order to measure it you must initially have a baseline of that behavior • In real life or therapeutic situations punishment is used to decrease some maladaptive behavior • Self injurious behavior • Drug taking • In the lab, we typically first train the animals to perform a behavior • Then introduce punishment to see if it suppresses responding • This can make things complicated • Is responding more influenced by reward or punishment? • It depends • Skinner’s paw slap

22. Characteristics of the Aversive Stimulus and its Method of Introduction • Types of Stimuli • Remember one form of punishment (positive punishment) involves presentation of an aversive stimulus • Shock • Loud noise • slap • Squirt of lemon juice in the mouth

23. negative punishment involves taking away something the organism wants • Loss of positive RF • Time out • Removal of personal freedoms • Can’t get typical RF

24. When is Punishment most effective? • Let’s go through what could be considered the “Rules for Effective Punishment” • This list is backed up by empirical findings from the animal literature • Think about how we often don’t follow these rules in real life though • 1)punishment must be delivered soon after a response to be most effective • “Catch them in the act” • Delayed punishment is far less effective • Can work well with your dog or cat. • Kids? • Criminals?

25. 2)Punishment must be strong as possible to be effective • Mild shock causes only moderate suppression of behavior • The effect of mild shock dissipates with repeated application • Habituation • Intense, longer lasting shocks are far more effective • Kids? • Criminals?

26. 3)Punishment must be delivered consistently to be effective. • Punishment works best if it is applied every time • How does this compare to the effects of partial reinforcement? • Kids? • Criminals?

27. 4)Punishment should be as strong as possible initially • It is not very effective to start off weak and then increase with repeated infractions. • Kids? • Criminals?

28. 5) Response-Contingent versus Response-Independent Aversive Stimulation • Random punishment can suppress responding. • Especially if intense • Learned helplessness • Typically, however, random punishment is not as effective as contingent punishment • With random punishment in a rat you might see some initial decline in responding • but as the animal becomes used to it responding tends to increase

29. 6)noncontingent punishment decreases the effectiveness of contingent punishment • If animals are shocked at random initially they take longer to associate shock with a specific stimulus, or response. • Phase 1: Random shocks • Phase 2: Lever press = shock • US preexposure effect • Kids? • Criminals?

30. 7)Punishment is more effective if animal if offered an alternative response to the punished response • Herman and Azrin (1964) • Human smokers • Two levers • Phase1 (Training) • Lever 1: cigarette VI schedule • Lever 2: cigarette VI schedule • Phase 2 (Test) • Condition 1 • Lever 1: loud noise; cigarette VI schedule • Lever 2: cigarette VI Schedule • Condition 2 • Lever 1: loud noise; cigarette VI schedule • Findings? • How much pressing of lever 1? • Condition 1? • Condition 2?

31. The findings from Herman and Azrin (1964) may seem obvious, but the implications are important • If you want to discourage a particular behavior, you can punish it. • But it would be more effective to punish that behavior while providing the organism alternative reinforcing/reinforced behaviors • Punish playing too much x-box, but supply lots of new books/magazines? • Punish self-injurious behavior, but supply other activities (painting, music, social interaction). • Providing alternative behavioral opportunities can make even mild punishment much more effective.

32. 8) Punishment can come under stimulus control • Discriminative punishment • Responding is punished in the presence of an S+ • Light indicates lever pressing will result in shock • Otherwise responding is RF • Animals quickly learn not to respond to the lever when a light is on. • Kids? • Parent present or not • Classroom effects • Teacher present • Substitute/weak teacher • Criminals? • Police car  speeding