Animals prefer reinforcement that follows greater effort: Justification of effort or within-trial contrast? (original) (raw)
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Reinforcers following greater effort are preferred: A within-trial contrast effect
2007
Justification of effort is a form of cognitive dissonance in which reinforcers are more valued when they are harder to obtain. Presumably, giving the reinforcer greater value justifies the greater effort needed to obtain it. But we have proposed that within-trial contrast between the end of the effort and the reinforcer (or signal for reinforcement) is responsible for this effect. We have found a similar effect in nonsocial tasks with adult humans and children. More important, we have found the effect in pigeons.
Journal of the Experimental Analysis of Behavior, 2007
When behavior suggests that the value of a reinforcer depends inversely on the value of the events that precede or follow it, the behavior has been described as a contrast effect. Three major forms of contrast have been studied: incentive contrast, in which a downward (or upward) shift in the magnitude of reinforcement produces a relatively stronger downward (or upward) shift in the vigor of a response; anticipatory contrast, in which a forthcoming improvement in reinforcement results in a relative reduction in consummatory response; and behavioral contrast, in which a decrease in the probability of reinforcement in one component of a multiple schedule results in an increase in responding in an unchanged component of the schedule. Here we discuss a possible fourth kind of contrast that we call within-trial contrast because within a discrete trial, the relative value of an event has an inverse effect on the relative value of the reinforcer that follows. We show that greater effort, longer delay to reinforcement, or the absence of food all result in an increase in the preference for positive discriminative stimuli that follow (relative to less effort, shorter delay, or the presence of food). We further distinguish this within-trial contrast effect from the effects of delay reduction. A general model of this form of contrast is proposed in which the value of a primary or conditioned reinforcer depends on the change in value from the value of the event that precedes it.
Journal of Experimental Social Psychology, 2010
The effort justification phenomenon, in which greater value is given to rewards that require more effort to obtain, is frequently explained in terms of cognitive dissonance . Here, we employed a novel combination of operant and lick analysis techniques to show that rats place more value on a sucrose reward when it follows high effort than when the same reward follows low effort. This is the first demonstration of a direct analogue of the effort justification phenomenon in nonhuman animals. As the behavior of rats is normally considered in terms of relatively simple mechanisms, the current results question the need for complex cognitive accounts for the effort justification phenomenon (in rats or humans). As an alternative, we examine the possibility that high effort produces an aversive state that enhances reward value by a process of contrast.
Justification of Effort by Humans and Pigeons Cognitive Dissonance or Contrast?
2010
Abstract Justification of effort by humans is a form of reducing cognitive dissonance by enhancing the value of rewards when they are more difficult to obtain. Presumably, assigning greater value to rewards provides justification for the greater effort needed to obtain them. We have found such effects in adult humans and children with a highly controlled laboratory task.
Preference for rewards that follow greater effort and greater delay
2008
Abstract Humans prefer (conditioned) rewards that follow greater effort (Aronson & Mills, 1959). This phenomenon can be interpreted as evidence for cognitive dissonance (or as justification of effort) but may also result from (1) the contrast between the relatively greater effort and the signal for reinforcement or (2) the delay reduction signaled by the conditioned reinforcer. In the present study, we examined the effect of prior force and prior time to produce stimuli associated with equal reinforcement.
A Within-trial Contrast Effect and its Implications for Several Social Psychological Phenomena
International Journal of Comparative Psychology, 2005
Contrast refers to a comparison between two conditions of reward such that the relation between them is magnified (relative to an appropriate control condition). It is an effect that is opposite in direction from generalization (which is a form of averaging). Three kinds of contrast have received substantial empirical attention: Incentive contrast in which a sudden change in reward (either an increase or a decrease) results in an overreaction to the change, relative to a control condition; anticipatory contrast in which an anticipated improvement in reward results in less consumption of an initial reward; and differential or behavioral contrast in which a change in reward associated with one stimulus results in a change in behavior associated with a second stimulus in the opposite direction. Here I discuss a fourth kind of contrast that I call within-trial contrast. In this form of contrast a discriminative stimulus is preferred when it follows a less appetitive event (effort, delay, or the absence of reward). A model of this kind of contrast is proposed that is based on a presumed change in the hedonic state of the organism between the end of the less appetitive event and the reward (or stimulus signaling the reward). It is distinguished from an account based on the relative reduction in delay to reinforcement. Finally, I suggest that a general form of this withintrial contrast may help to explain various complex human social phenomena including cognitive dissonance, justification of effort, the effect of extrinsic rewards on behavior that is maintained by intrinsic rewards, and learned industriousness.
THE EFFECT OF RESPONSE RATE ON REWARD VALUE IN A SELF-CONTROL TASK
To understand how effort, defined by number of responses required to obtain a reward, affects reward value, five pigeons were exposed to a self-control task. They chose between two alternatives, 2 s of access to food after a delay of 10 s, and 6 s of access to food after an adjusting delay. The adjusting delay increased or decreased depending on the pigeons' choices. The delay at which the two alternatives were equally chosen defined the indifference point. To determine whether requiring responses during the delay led to more impulsive (smaller-sooner rewards) or self-controlled (larger-later rewards) choices, we varied the number of required pecks during the 10-s delay to the 2-s reinforcer, and assessed how the requirement affected the indifference points. In the High Rate Phase, they had to peck at least 10 times during the delay; in the Low Rate Phase, they could peck at most 5 times during the delay. For four pigeons the indifference point increased with the response requirement; for one pigeon it decreased. The results suggest that, in general, reward value varies inversely with effort.
Preference for a Stimulus that Follows a Relatively Aversive Event: Contrast or Delay Reduction?
Journal of the Experimental Analysis of Behavior, 2007
Several types of contrast effects have been identified including incentive contrast, anticipatory contrast, and behavioral contrast. proposed a type of contrast that appears to be different from these others and called it within-trial contrast. In this form of contrast the relative value of a reinforcer depends on the events that occur immediately prior to the reinforcer. Reinforcers that follow relatively aversive events are preferred over those that follow less aversive events. In many cases the delay reduction hypothesis proposed by Fantino (1969) also can account for such effects. The current experiments provide a direct test of the delay reduction and contrast hypotheses by manipulating the schedule of reinforcement while holding trial duration constant. In Experiment 1, preference for fixed-interval (FI) versus differential-reinforcement-of-other-behavior (DRO) schedules of reinforcement was assessed. Some pigeons preferred one schedule over the other while others demonstrated a position (side) preference. Thus, no systematic preference was found. In Experiment 2, a simultaneous color discrimination followed the FI or DRO schedule, and following training, preference was assessed by presenting the two positive stimuli simultaneously. Consistent with the contrast hypothesis, pigeons showed a significant preference for the positive stimulus that in training had followed their less preferred schedule.
Effort-motivated behavior resolves paradoxes in appetitive conditioning
Behavioural Processes, 2021
Motivated behavior has long been studied by psychologists, ethologists, and neuroscientists. To date, many scientists agree with the view that cue and reward attraction is the product of a dopamine-dependent unconscious process called incentive salience or "wanting". This process allows the influence of multiple factors such as hunger and odors on motivational attraction. In some cases, however, the resulting motivated behavior differs from what the incentive salience hypothesis would predict. I argue that seeking behavior under reward uncertainty illustrates this situation: Organisms do not just "want" (appetite-based attraction) cues that are inconsistent or associated with reward occasionally, they "hope" that those cues will consistently predict reward procurement in the ongoing trial. Said otherwise, they become motivated to invest time and energy to find consistent cue-reward associations despite no guarantee of success (effort-based attraction). A multi-test comparison of performance between individuals trained under uncertainty and certainty reveals behavioral paradoxes suggesting that the concept of incentive salience cannot fully account for responding to inconsistent cues. A mathematical model explains how appetite-based and effort-based attractions might combine their effects.