Chapter Outline

Chapter Outline

1. THE AVERSIVE EVENTS AROUND US

   Many unpleasant situations are encountered throughout life. Some events can be escaped but not avoided. Other events can be avoided if a certain response is learned that precludes the occurrence of the aversive event. Finally, punishment is often experienced following the display of an unwanted behavior. Because the environment contains aversive events, it is imperative that organisms learn adaptive ways to deal with adversity.

2. ESCAPE CONDITIONING

   An escape response is an instrumental behavior that is motivated by an aversive event and is rewarded by the termination of the event.

   1. The Escape from Aversive Events: Several factors influence the acquisition of the escape response.

      1. The Intensity of the Aversive Event

         The intensity of the aversive event controls the rate of escape conditioning. For example, Trapold and Fowler (1960) trained rats to escape electric shock. The rats received either 120, 160, 240, 300, or 400 volts of electric shock in the start box of an alley. The results of the experiment indicated that the greater the shock intensity, the shorter the latency to escape from the start box.

      2. The Absence of Reward

         The strength of learned escape behavior is influenced by the degree to which the aversive event is reduced by the escape response. For instance, Campbell and Kraeling (1953) gave rats a 400-volt electric shock in the start box of an alley. When the escape response was completed, the shock was reduced to either 0, 100, 200, or 300-volts. Thus, greater reductions in the intensity of the shock enhanced escape performance.

      3. The Impact of Delayed Reward

         Delaying the termination of the aversive event following the escape behavior negatively affects performance. As an example, Fowler and Trapold (1962) delayed the termination of an electric shock by either 0, 1, 2, 4, 8, or 16 seconds following the escape response. Longer delays interfered with the acquisition of the escape response.

   2. The Elimination of an Escape Response: Eliminating a learned escape response can be accomplished by no longer presenting the aversive event or by no longer terminating the aversive event following the escape response.

      1. The Removal of Negative Reward

         An escape response may be extinguished if the aversive event continues to occur even after the escape response has been made.

      2. The Absence of Aversive Events

         Elimination of an escape response also occurs when the aversive event has been discontinued. However, the escape response may occur many times before disappearing due to the continuing motivational influence supplied by conditioned fear.

      3. Vicious-Circle Behavior

         Brown and his associates observed a special situation in which escape responding continues despite the fact that the subject is punished for making the response. The persistence of escape responding despite the delivery of punishment is called vicious-circle behavior. Vicious-circle behavior is presumed to occur from the motivational influence of fear conditioned to environmental cues. The resulting punishment serves to reinforce the fear thus maintaining the motivation for the escape response.

3. The Avoidance of Aversive Events

   Avoidance conditioning involves the learning of a response that serves to prevent the occurrence of an aversive event.

   1. Types of Avoidance Behavior: An active avoidance response is one that prevents the occurrence of an aversive event. A passive avoidance response, on the other hand, is the withholding of responding to prevent an aversive event.

      1. Active Avoidance Learning

         The paradigm for active avoidance conditioning was developed by Mowrer (1938, 1939). In active avoidance conditioning, an environmental stimulus (CS) is paired with the delivery of a painful event (UCS). Subjects first learn to escape from the aversive event. Eventually, the escape response begins to occur when the CS is presented and before the arrival of the UCS. Under these conditions, the response prevents the delivery of the aversive event.

      2. Passive Avoidance Learning

         Subjects can also learn to avoid an aversive event if by withholding a response the aversive event does not occur.

   2. How Readily is Avoidance Behavior Learned?

      1. The Severity of the Aversive Event

         One important factor determining how well a learned response occurs is the intensity of the aversive event. In many situations, increases in the intensity of the aversive event produce higher levels of avoidance conditioning. However, the opposite relationship holds true in the two-way avoidance situation.

      2. Passive Avoidance Behavio

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         Increases in the intensity of the aversive event enhance conditioning in the passive avoidance situation.

      3. One-Way Active Avoidance Behavior

         In a one-way active avoidance situation, increases in the intensity of the aversive event also enhance conditioning.

      4. Two-Way Active Avoidance Behavior

         In a two-way active avoidance situation, the subject (usually a rat) is presented with a CS and must run to a chamber (side B) before an aversive event is presented. Then, after a short period of time, the CS is presented again and the subject must return to the original chamber (side A) to avoid the aversive event. Increases in the intensity of the aversive event produce decrements in performance in this situation. This outcome may be due to the subject experiencing conflict because the aversive event has been associated with chambers that also serve a safety function. Increases in the intensity of the aversive event may enhance the level of conflict.

      5. The Delay Between the CS and the UCS

         Longer temporal intervals between the presentation of the environmental CS and the aversive UCS interfere with conditioning of the avoidance response. Presumably, longer CS-UCS intervals are detrimental to the conditioning of fear to the CS, which is important for motivating the avoidance response.

   3. Application: Response Prevention or Flooding: Response prevention or flooding is a form of behavior therapy in which a phobia is eliminated by forced exposure to the feared stimulus without any aversive consequences. A large number of studies have reported positive results using flooding to eliminate phobias, panic disorder, and obsessive-compulsive behavior.

4. PUNISHMENT

   Punishment is a form of conditioning that can eliminate unwanted behavior by the use of an aversive event contingent upon the occurrence of the unwanted response.

   1. Types of Punishers: Positive punishment refers to the delivery of a physically or psychologically painful event following the occurrence of an unwanted behavior. Negative punishment (Omission training) involves the loss of positive reinforcement due to the occurrence of an unwanted behavior. There are two types of negative punishment. One type is called response cost which involves the withdrawal of positive reinforcement when an unwanted response occurs. The other type of negative punishment is called time-out from reinforcement which involves a period of time during which reinforcement for responding is unavailable.

   2. The Effectiveness of Punishment: Skinner (1938) concluded that punishment suppresses behavior on a temporary basis. However, subsequent research has shown that a number of variables determine whether punishment is effective in suppressing behavior.

   3. When is Punishment Effective?: Three factors determine the effectiveness of punishment in suppressing behavior.

      1. The Severity of Punishment

         Mild punishment produces little, if any, suppression of the punished response. An extremely strong punishing event is more likely to produce complete suppression of a punished behavior in both humans and nonhumans.

      2. The Consistency of Punishment

         For nonhumans and humans, punishment is more effective when it is administered in a consistent manner than when it is administered intermittently.

      3. Delay of Punishment

         In nonhumans and humans, punishment is more effective when it occurs immediately after the completion of the unwanted behavior than if the punishing event is delayed for a time.

   4. The Negative Consequences of Punishment: Punishment procedures can produce several undesirable effects.

      1. Pain-Induced Aggression

         Punishment often leads to aggressive behavior. At least in humans, such pain-induced aggression apparently occurs because punishment elicits anger, and anger leads to aggression.

      2. The Modeling of Aggression

         Experiments show that children often mimic other peoples' behavior, a phenomenon called modeling. After observing a model's aggressive behavior, children's aggressiveness increases. More specifically, children tend to use the same type of punishment that they have received. In addition, children often model punishment that is delivered to them, and there is a correlation between the use of punishment by parents and the level of aggressive behavior in their children.

      3. The Aversive Quality of a Punisher

         Humans and nonhumans learn, through classical conditioning, about cues that accompany punishment, and those cues become capable of eliciting fear. Such cues, which may include a parent who delivers punishment to a child, may motivate behaviors to escape those cues.

      4. Additional Negative Effects of Punishment

         Delivery of aversive stimulation (punishment) can be problematic for other reasons. First, suppressing one behavior through punishment can lead to suppression of similar behaviors through generalization. Second, subjects may not perceive the contingency between the punishing event and the behavior it is intended to suppress, and this can lead to helplessness and depression.

   5. Application: The Use of Punishment: Punishment is commonly used in human society, including spanking of children by parents, disapproval of student behavior by teachers, and fines for violating laws. Several procedures are known to be effective in suppressing unwanted behaviors.

      1. Positive Punishment

         Positive punishment is the presentation of a painful event following an unwanted response. Positive punishment has been used clinically to suppress the occurrence of several types of maladaptive behaviors. However, one problem with the therapeutic use of positive punishment is the possibility that the effects of punishment will generalize to situations outside the clinical setting.

      2. Response Cost

         Response cost is a negative punishment technique in which the occurrence of an undesired behavior results in the withdrawal or the failure to obtain positive reinforcement. Response cost techniques are effective in controlling the occurrence of several maladaptive responses.

      3. Time-Out from Reinforcement

         Time-out from reinforcement, another negative punishment procedure, refers to a program in which the occurrence of an inappropriate behavior results in the loss of access to positive reinforcement for a designated period of time. This procedure also has been shown to be effective in controlling the occurrence of several types of maladaptive behaviors.

      4. The Ethical Use of Punishment

         Because punishment can lead to unwanted outcomes, the administration and use of punishment must always be guided by law and ethics. State and Federal laws concerning the appropriate use of punishment have been adopted, and the American Psychological Association's Ethical Principles of Psychologists (1992) guide therapists and researchers in the use of punishment.