THEORIES AND APPLICATIONS OF AVERSIVE CONDITIONING Chapter 7 1

Escape, Avoidance, & Punishment 2  We usually respond to aversive events by either  1) making a response the will let us escape from the aversive situation (Escape), or  2) making a response that will let us avoid the aversive situation (Avoidance), or  3) stop doing something that caused an aversive (Punishment)

Escape Conditioning 3  Escape response: a behavioral response to an aversive event that is reinforced by the termination of the aversive event

4 ¼ wheel turn terminates a tail shock Pressing button removes cold Escape Examples Proposal Gone Bad

AKA“Negative” Reinforcement SRO Aversive Negative Relationship p(O/R) < p(O/noR) 5

Escape from Aversive Events 6  Several factors play a role in determining whether an organism learns to escape aversive events  Intensity of the aversive stimulus (facilitates learning)  Absence of negative reinforcement (impairs learning)  Impact of delayed reinforcement (impairs learning)  There are also many factors that affect the efficiency of the escape response

Elimination of an Escape Responses 7  An escape response can be extinguished  No longer terminating the aversive stimulus following the escape response  However, the response will continue for some time until the organism learns that the escape response no longer terminates the aversive event

Vicious Circle Behavior 8  Vicious circle behavior: an escape response that continues despite punishment, due to a failure to recognize that the absence of the escape behavior will not be punished  It occurs because the organism doesn’t realize that not responding will not lead to punishment

The Avoidance of Aversive Events 9  Avoidance response: a behavioral response that prevents a potential aversive event  Active (Do something)  Passive (Don’t do something)

Passive Avoidance Behavior 10  Refers to avoiding a potential aversive by not acting.  Don’t jump off the10 meter diving board  In passive avoidance situations, the more severe the aversive event, the faster the acquisition of the passive avoidance response

One-Way Active (Subject Escapes) Response Warning CS Shock US Time 11

Response Warning CS Shock US Time One-Way Active (Subject Avoids) 12

Two-Way Active Avoidance Behavior 13  The organism is placed in one chamber (A) and exposed to a cue before it is shocked  To avoid the shock, it must run to the other side (B) before the shock is presented  After this, the animal remains in side B for a short intertrial interval (ITI)

Two-Way Signaled Active Rat Shuttle Box Gridshock= US 14 Light= CS

15  The stimulus is then presented again and the animal must run back to side A  Thus, the animal avoids the shock by running back to the place it was previously shocked  This model requires the animal to ignore situational and contextual cues and pay attention to only one cue (the signal)

20 s40 s60 s R-S interval: S-S interval: Two-Way Unsignaled Active 16

The Severity of the Aversive Event 17  In most cases, the greater the severity of the aversive event, the more readily the subject will learn the avoidance response  The final level of performance is also higher in most cases  Two-Way active avoidance is often impaired with increasing intensity.

18  In the two-way avoidance model, learning is inversely related to severity of shock  That is, the more severe the shock, the slower the learning of the response  This may be due to the fact that the animal experiences conflict about going back into the place it was previously shocked The greater the shock, the greater the conflict

Avoidance Puzzle Question: How can the absence of an event act as a reinforcer? Answer: Something tangible has happened. Fear is removed inside the organism. 19

Mowrer’s Two-Process Theory of Avoidance 1. (Pavlovian): Pairings of situational CSs with an aversive US cause a fear CR to develop 2. (Instrumental): Responding causes removal of the CS, which in turn removes the fear CR Avoidance learning is escape learning; the organism learns to escape from the CS and the fear that it elicits. 20

Is Fear Termination a Reinforcer? CS-US Conditioning Tone  Shock Stage 1 Stage 2 Escape Shuttle  Tone Off 21

23  D’Amato asserts that we are motivated to approach situations associated with relief as well as to escape events paired with aversive events  The relief experienced following avoidance behavior rewards the response  Removal of anticipatory pain (US) as well as anticipatory fear (CS) might also play a role D’Amato’s Modification of Two-Process

3. Level of fear is not always positively correlated with avoidance (fearless avoidance) 2. Avoidance does not readily extinguish 1. “Unsignaled” avoidance Four Challenges for the Two-Process Theory Extinguish warning stimulus doesn’t always eliminate avoidance

Fear in Active Avoidance? Stage 1Stage 2 Active avoidance training Does warning CS suppress lever pressing? Fear declines with trials 25

Cognitive View of Avoidance  Calculation of what choice will likely yield a better (less dangerous) situation  Military “Malingers”  PTSD 26

3. Response as a stimulus that inhibits fear (safety signal) 1.Temporal conditioning 2.“Conservation of fear” (Response so quick the feared stimulus not fully experienced) Answers from Two-Process Theory of Avoidance 4. Well learned response trigger by very small amounts of fear (habit learning) 5. “Response blocking” or “flooding” should increase fear 27

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29  Although flooding seems to be very effective, many people do not want to participate in flooding because the initial anxiety is so great

Alternative Theoretical Accounts of Avoidance Behavior Species-Specific Defense Reactions (SSDRs)  more concerned with the actual response  aversive stimuli elicit strong innate responses (e.g., freezing, flight to dark area, fighting)  species typical responses are readily learned as avoidance responses (e.g., jump = two trials versus lever-press = 1000s of trials)  punishment originally thought to be responsible for the selection of the avoidance response 30

Punishment 31  Punishment: use of an aversive event contingent on the occurrence of an inappropriate behavior  The intent of punishment is to suppress an undesired behavior  If punishment is effective the frequency, intensity, or both will decline

32 THE NATURE OF PUNISHMENT  Thorndike’s Negative Law of Effect  The negative law of effect states that punishment weakens the strength of an S-R bond  The recovery of responding shortly after exposure to a mild punishment contradicts this view because the weakened bond should be permanent, not temporary

Skinner’s Experiment on Punishment Stage 1: Rats were reinforced with food on a VI schedule Stage 2: Extinction for two successive days First 10 min of extinction: One group of rats was punished Another group was not punished 33

Skinner concluded that punishment was not an effective way to control behavior (refutes “negative law of effect”).

The Effectiveness of Punishment 35  Punishment appears to suppress unwanted behaviors  However, the suppression is often temporary  In some cases, however, punishment permanently suppresses unwanted behaviors

Increasing Effectiveness  intense/prolonged from start (no ramping up)  response contingent rather than response independent  immediately after the response rather than delayed  continuous rather than partial reinforcement schedule 36

Increasing Effectiveness  punished response is not otherwise being reinforced  there is an alternative response to acquire reinforcer  the punished response is not a species-specific defence reaction  unsignaled 38

Problems  person associated with punishment becomes aversive (40 to 1 rule)  general suppression of responding  imitation of the aggressive behavior involved in punishment; pain-initiated aggression  identifying punishers is difficult (attention might be positive)  escape/avoidance or aggressive responses in punishing situation (aka “vicious circle”) 39

Types of Punishment 40  Punishment is the response-contingent presentation of an aversive event  Positive punishment: addition of an aversive event (e.g. spanking) to reduce the undesirable behavior  Negative punishment: removal of an appetitive event (watching TV) to reduce an unwanted behavior (aka: omission)

Categories 41  There are two categories of negative punishment  Response cost: an undesired response results in either the withdrawal of or failure to obtain reinforcement.  Time-out from reinforcement (time out): a period of time during which reinforcement is unavailable

Response Cost  Response cost:  A negative punishment technique in which an undesired response results in either the withdrawal of or failure to obtain reinforcement  Response cost is a form of negative punishment  It refers to a penalty or fine contingent upon the occurrence of an undesired behavior 42

43  Response cost has been used to successfully treat a wide range of behaviors including:  Self mutilation  Smoking  Overeating  Tardiness  Aggressiveness

Time Out 44  Time out from reinforcement  A negative punishment technique in which an inappropriate behavior leads to a period of time during which reinforcement is unavailable  If a time out area is used, it must not be reinforcing