Chapter 8 Notes: Consequences of Responding - Escape and Avoidance
Consequences of Responding: Escape and Avoidance
Etymology
Escape: Derived from Old North French "escaper," meaning to take off one's cloak or free oneself. Indicates a direct action to get away from something.
Avoidance: Shares the sense of "getting out of," related to words like vacant, evacuate, vanish, and waste. Signifies actions taken to prevent exposure to something.
Aversive: From Latin "a" (away) + "vertere" (to turn). "Vertere" is related to the Germanic suffix "-ward" or "-wards," implying warding off or guarding. Highlights the active turning away from unpleasant stimuli.
Key Concepts
Escape: Terminating an existing aversive stimulus. Represents an active response to stop an ongoing negative experience.
Avoidance: Preventing or delaying an aversive stimulus. Involves preemptive actions to ensure a negative experience does not occur or is postponed.
Negative Reinforcement: A response terminates or prevents an aversive stimulus, increasing the probability of that response. Core mechanism behind both escape and avoidance; the removal or prevention of the aversive stimulus strengthens the behavior.
Positive Reinforcement: A response produces a stimulus. Contrasts with negative reinforcement by focusing on the addition of a stimulus to increase behavior probability.
Punishment: Decreases the likelihood of a response. Serves to reduce unwanted behaviors by associating them with negative outcomes.
Introduction
Organisms act to eliminate aversive stimuli. If presenting an aversive stimulus punishes a response, removing or preventing it may reinforce the response. This is negative reinforcement. This underscores the fundamental principle that organisms are motivated to avoid unpleasant experiences, shaping their behavior through both escape and avoidance.
Positive reinforcement involves producing a stimulus, while negative reinforcement involves removing one. The distinction lies in whether the behavior results in adding something desirable or removing something undesirable.
Vocabulary of Reinforcement and Punishment
Reinforcement: Increases the reinforced response. Reinforcement always aims to increase the frequency or intensity of a behavior.
Punishment: Decreases the punished response. Punishment is designed to reduce or eliminate a behavior.
Positive Modifier: Consequence is the addition of a stimulus. Indicates that a stimulus is being added to the situation.
Negative Modifier: Consequence is the subtraction of a stimulus. Indicates that a stimulus is being removed from the situation.
Reinforcers and punishers are stimuli, not the absence of stimuli, although this distinction can be ambiguous. Clarifies that reinforcement and punishment involve tangible stimuli rather than just the lack thereof, although this can be context-dependent.
Escape
Escape procedures involve a response that terminates an aversive stimulus. This differs from avoidance, where the response prevents or delays the stimulus. Highlight the proactive termination of an ongoing aversive experience.
Example: Leaving a party to escape the company vs. avoiding someone expected to arrive. Illustrates the difference between directly ending exposure to an aversive event and preventing exposure in the first place.
In institutional settings, aggression in children may be a way to escape demands. Replacing aggression with incompatible behavior can reduce it. Demonstrates how maladaptive behaviors can be replaced with more appropriate responses.
Escape can be studied in rats using an electrified grid floor. Running speed increases when shock termination is immediate. This illustrates quantitative effects of reinforcement (delay and magnitude parameters). It provides an experimental method to measure the effectiveness of escape behavior based on how quickly and intensely rats respond to shock termination.
Elicited Responding and Escape
Research on escape is less common than on avoidance. It's often easier to increase behavior using positive reinforcement than negative reinforcement in escape procedures. This is due to temporal relations between reinforced responses and other responses.
In positive reinforcement, the reinforcer is absent when the response occurs. In negative reinforcement, the aversive stimulus is present before the response. This temporal relationship affects how the reinforcer influences behavior.
The aversive stimulus can generate competing responses. For example, shock elicits jumping, which competes with lever pressing. Similarly, bright light may cause a rat to hide, making lever pressing less likely. These competing responses can reduce the effectiveness of the escape behavior.
Ambiguous Distinction between Positive and Negative Reinforcement
Whether stimuli are presented or removed might be less important than whether responses generated by the reinforcer compete with the reinforced response. This challenges the traditional distinction, suggesting that the type of response elicited by the reinforcer may be more critical.
Example: A rat in a cold chamber presses a lever to activate a heat lamp. Is this positive reinforcement (adding heat) or negative reinforcement (removing cold)? Turning on the heat lamp makes huddled corner responses less likely, similar to shock escape. This example illustrates how the same scenario can be interpreted in different ways, complicating the classification of reinforcement type.
Reinforcement always involves a change, leading to differences in responding before and after the change. Effects range from competing responses to those that increase the likelihood of reinforced responses. The change in environment or condition is what drives the behavioral response.
In workplaces, praise is likely preferred over threats, even if both motivate employees equally. Highlights the practical implications of understanding reinforcement types in human behavior, showing that positive methods are often more effective and preferred.
Positive and Negative Punishment
Responses can be punished by events (e.g., shock) or the termination of events (e.g., removing food). Introduces the two types of punishment based on the presentation or removal of stimuli.
Negative punishment can be hard to demonstrate: a food-deprived rat will probably eat rather than press a lever, limiting opportunities to punish lever pressing. Explains the practical challenges in implementing negative punishment in certain experimental conditions.
Studies of negative punishment often remove a stimulus in the presence of which responses are reinforced (timeout). This provides a specific example of how negative punishment is studied, focusing on the removal of a reinforcing stimulus.
Identifying Contingencies: Procedural and Behavioral Criteria
Terminology: The first word (positive/negative) refers to presentation/removal; the second (reinforcement/punishment) refers to whether responding increases/decreases. Clarifies the terminology used in describing different types of reinforcement and punishment.
Behavioral criteria are more relevant than procedural ones. The rat in the cold chamber example can be categorized differently depending on whether we describe it in terms of presenting/removing heat or cold. Emphasizes that the actual effect on behavior is more crucial than the specific procedure used.
Procedures that produce behavior unlikely to compete with the reinforced response are categorized as positive reinforcement; those that produce competing behavior are negative reinforcement. This provides a guideline for categorizing reinforcement types based on the nature of the elicited responses.
Touching the Hot Stove: Natural Aversive Contingencies
Reinforcement contingencies are neither inherently good nor bad. Aversive control is also ubiquitous and unavoidable. Acknowledges that both reinforcement and punishment are natural parts of learning and survival.
Without punishment, we wouldn't learn to avoid dangers (e.g., hot stoves). Without negative reinforcement, we wouldn't learn to escape rain or avoid cheaters. Illustrates the necessity of aversive control in learning to avoid harmful situations and behaviors.
Aversive or reinforcing properties depend on context. A buzzer can be a reinforcer or punisher depending on whether it's associated with shock or food. Shows that the same stimulus can have different effects based on prior associations and context.
School can be reinforcing (escape from abuse) or punishing (bullies) depending on the child's circumstances. Demonstrates how the same environment can have different effects based on individual experiences and circumstances.
Avoidance
In avoidance, the aversive stimulus isn't present when the reinforced response occurs. Key distinction from escape, where the aversive stimulus is already present.
Two types:
Deletion: Preventing the aversive stimulus entirely (swatting a mosquito before it bites).
Postponement: Delaying the aversive stimulus (putting coins in a parking meter).
Deletion example: A rat presses a lever to omit a shock. Avoidance is complete if pressing occurs at least once a minute.
Postponement example: Sidman avoidance (1953). Two clocks: SS interval (shock-shock) and RS interval (response-shock). Lever presses reset the RS interval, postponing the shock. The rat can postpone indefinitely by pressing before the RS interval ends. This allows avoidance responding to be studied independently of escape responding. If the RS interval is shorter than the SS interval, certain response patterns can increase shock frequency, effectively punishing the response.
Avoidance behavior can be persistent but hard to initiate. Safety measures are not often shaped by natural contingencies.
Taking preventive medication is followed by nothing happening, making compliance difficult to shape and maintain. This applies to various preventive measures. Highlights the challenges in maintaining behaviors that prevent negative outcomes because the consequences are not immediately apparent.
The Nature of the Reinforcer in Avoidance
A key issue is what reinforces avoidance. One view is that organisms avoid by escaping features of a situation previously associated with aversive stimuli.
Two-process theory of avoidance: a warning stimulus acquires aversive properties through its relation to shock, and terminating the warning stimulus reinforces the avoidance response.
Sidman's avoidance schedule aimed to demonstrate avoidance without a warning stimulus.
Alternative view: the organism's state after a response, when shock isn't imminent, is reinforcing.
Debates shifted to experimental questions about conditions maintaining avoidance: Is reducing total shocks necessary, or is postponing individual shocks sufficient? Both can maintain responding. Operant establishing make negative reinforcers effective for avoidance behavior.
The presentation of aversive stimuli makes their removal reinforcing.
Avoidance involves transitions between situations; effectiveness is determined by both the preceding and following situations.
Maintaining avoidance when not all shocks are avoidable leads to a discussion of molecular vs. molar analyses. For example, Herrnstein and Hineline (1966) used probabilistic shocks to demonstrate how changing the shock probability based on behavior will affect avoidance behaviors.
Molecular Analysis: Moment-to-moment sequences of events in time.
Molar Analysis: Rates or relationships measured over extended time periods.
Evolution has equipped organisms to respond to properties of situations. Organisms can postpone shocks within trials without reducing overall shock rate or reduce overall shock rate while shortening time to next shock.
Extinction After Negative Reinforcement
Effects of negative reinforcement are temporary. Effects of terminating contingencies must be distinguished from simply terminating the aversive stimuli.
In shock escape, turning off the shock eliminates responding. In avoidance, turning off the shock source is considered an extinction procedure.
Avoidance responding is persistent after aversive stimuli are discontinued, relating to human compulsions.
Discontinuing the aversive stimulus is a common extinction procedure.
Extinction after negative reinforcement parallels accounts of extinction after positive reinforcement.
The Language of Aversive Control
Stimuli that reinforce by presentation can also punish by removal, and vice versa.
Aversive stimuli can be punishers, negative reinforcers, and elicitors, depending on context.
Symmetry of reinforcement and punishment has limits.
Some describe punishment in terms of passive avoidance, but this can be expanded to include reinforcement as well by the organism not-responding. Direct descriptions of recordable responses is preferred.
Addendum 8A: Species-Specific Defense Reactions
Avoidance is easier if the reinforced response is compatible with responses generated by aversive stimuli.
Organisms have species-specific defense responses that are triggered by aversive situations (Bolles, 1970; Seligman, 1970).
Example: Pigeons avoid shock more readily by moving than by pecking (MacPhail, 1968).
Locomotor responses are likely to be elicited by aversive stimuli.
After avoidance begins, it may continue because it prevents shock or because it's species-specific behavior.
Some differences depend on species-specific determinants of what is aversive. Beavers avoid running water, motivating dam building (Hartman, 1975).
Addendum 8A: Species-Specific Defense Reactions
Avoidance is easier if the reinforced response is compatible with responses generated by aversive stimuli.
Organisms have species-specific defense responses that are triggered by aversive situations (Bolles, 1970; Seligman, 1970). These innate reactions can vary greatly, illustrating how different species adapt their behaviors to enhance survival in response to distinct threats.
Example: Pigeons avoid shock more readily by moving than by pecking (MacPhail, 1968).
Locomotor responses are likely to be elicited by aversive stimuli. These locomotor responses demonstrate an innate mechanism for survival, allowing organisms to escape or avoid danger effectively. This instinctive behavior not only enhances immediate survival chances but also contributes to the overall evolutionary fitness of species over time.
After avoidance begins, it may continue because it prevents shock or because it's species-specific behavior. Additionally, this phenomenon illustrates how avoidance behaviors can become learned responses over time, reinforcing the idea that both genetic predispositions and environmental influences play crucial roles in shaping these survival strategies.
Some differences depend on species-specific determinants of what is aversive. Beavers avoid running water, motivating dam building (Hartman, 1975).