Increased False-Memory Susceptibility After Mindfulness Meditation.

The effect of mindfulness meditation on false-memory susceptibility was examined in three experiments. Because mindfulness meditation encourages judgment-free thoughts and feelings, we predicted that participants in the mindfulness condition would be especially likely to form false memories. In two experiments, participants were randomly assigned to either a mindfulness induction, in which they were instructed to focus attention on their breathing, or a mind-wandering induction, in which they were instructed to think about whatever came to mind. The overall number of words from the Deese-Roediger-McDermott paradigm that were correctly recalled did not differ between conditions. However, participants in the mindfulness condition were significantly more likely to report critical nonstudied items than participants in the control condition. In a third experiment, which tested recognition and used a reality-monitoring paradigm, participants had reduced reality-monitoring accuracy after completing the mindfulness induction. These results demonstrate a potential unintended consequence of mindfulness meditation in which memories become less reliable.

Hyperbolic discounting of delayed social interaction.

The temporal discounting literature has demonstrated that the loss in value for delayed outcomes is most accurately modeled using a hyperbolic discounting equation. The hyperbolic-shaped function not only describes the shape of discounting for monetary outcomes, but also for other tangibles, such as alcohol, candy, CDs, erotica, cigarettes, cocaine, books, and DVDs. Furthermore, this hyperbolic shape has important theoretical implications. Despite the broad list of outcomes that are hyperbolically discounted, one class of outcomes has only recently received attention: social interactions. For the present study, we used standard binary-choice discounting procedures to explore the function that most accurately describes the change in value of delayed social interactions. The results from the present study suggest that, for 93 participants, the same equations (exponential, hyperbolic, and hyperboloid) used to describe the discounting of nonsocial commodities also describe the relation between delay and the value of social interaction. Similar to previous findings for nonsocial outcomes, the hyperbolic-shaped models provide a fit to the data superior to that of the exponential model.

Differences in Mood, Optimism, and Risk-Taking Behavior Between American and Chinese College Students.

Mood and optimism have been demonstrated to influence risk-taking decisions; however, the literature on mood, optimism, and decision-making is mixed and conducted primarily with western samples. This study sought to address this gap in the literature by examining the impact of mood and dispositional optimism on risk-taking and whether these associations differed between undergraduate students from the United States (N = 141) and the People's Republic of China (N = 90). Both samples completed a dispositional optimism questionnaire and an autobiographical mood induction task. They were then tasked with choosing to complete the Raven's Advanced Progressive Matrices reasoning task on easy, medium, or hard difficulty for hypothetical money. Selecting harder difficulties was interpreted as more risk-taking due to a higher chance of failure. More positive mood and higher dispositional optimism were associated with decreased risk-taking, i.e., selecting easier puzzle difficulties, in the American sample but increased risk-taking decisions, i.e., selecting harder difficulties, in the Chinese sample (p < 0.05 for all). These findings suggest that the effect of mood and optimism on decision-making may differ by nationality and/or culture.

Commodity specific rates of temporal discounting: does metabolic function underlie differences in rates of discounting?

Discounting rates vary as a function of commodity type. Previous studies suggest five potential characteristics of the commodity that could explain these differences: type of reinforcer (primary or secondary), if the commodity is perishable, if the commodity is satiable, if the commodity can be directly consumed, and immediacy of consumption. This paper suggests that these characteristics may best be viewed as related to a more fundamental characteristic: metabolic processing. In order to explore the possibility that metabolic processing underlies changes in discount rates, the difference in discounting between food, money, music CDs, DVDs, and books are compared. Music CDs, DVDs, and books share many characteristics in common with food, including gaining value through a physiological process, but are not directly metabolized. Results are consistent with previous findings of commodity specific discount rates and show that metabolic function plays a role in determining discount rates with those commodities that are metabolized being discounted at a higher rate. These results are interpreted as evidence that the discount rate for different commodities lies along a continuum with those that serve an exchange function rather than a direct function (money) anchoring the low end and those that serve a direct metabolic function capping the high end (food, alcohol, drugs).

Behavior analysis: thriving, but how about its future?

Behavior analysis has been thriving by continuing to make important theoretical and empirical contributions to a wide array of problems, as well as by contributing to interdisciplinary research. Applied research in behavior analysis is flourishing. Despite these positive signs there may be an erosion of support for basic research in animal learning and behavior, including behavior analysis. Increased attention by behavior analysts to fundamental problems in areas of cognition, including decision-making and language, may help behavior analysis to evolve more successfully. An experimental analysis of gambling may prove particularly fruitful.

How reinforcer type affects choice in economic games.

Behavioral economists stress that experiments on judgment and decision-making using economic games should be played with real money if the results are to have generality. Behavior analysts have sometimes disputed this contention and have reported results in which hypothetical rewards and real money have produced comparable outcomes. We review studies that have compared hypothetical and real money and discuss the results of two relevant experiments. In the first, using the Sharing Game developed in our laboratory, subjects' choices differed markedly depending on whether the rewards were real or hypothetical. In the second, using the Ultimatum and Dictator Games, we again found sharp differences between real and hypothetical rewards. However, this study also showed that time off from a tedious task could serve as a reinforcer every bit as potent as money. In addition to their empirical and theoretical contributions, these studies make the methodological point that meaningful studies may be conducted with economic games without spending money: time off from a tedious task can serve as a powerful reward.

The effect of conditioned reinforcement rate on choice: a review.

We review the nature of conditioned reinforcement, including evidence that conditioned reinforcers maintain choice behavior in concurrent schedules and that they elevate responding in the terminal links of concurrent-chains schedules. A question has resurfaced recently: Do theories of choice in concurrent-chains schedules need to include a term reflecting greater preference for higher rates of conditioned reinforcement? The review of several studies addressing this point suggests that such a term is inappropriate. Elevated rates of conditioned reinforcement (and responding) in the terminal links of concurrent-chains schedules do not lead to greater preference in the initial link leading to the higher rate of conditioned reinforcement. If anything, the opposite preference is likely to occur. This result is not surprising, since the additional putative conditioned reinforcers in the terminal link are not correlated with a reduction in time to primary reinforcement nor with an increase in value.

Influence of budget and reinforcement location on risk-sensitive preference.

Little is known about the effect that procedural variables have on risk-sensitive preference. This study assessed the effect of procedural variables on pigeons' choice between a fixed and variable amount of reinforcement (amount risk) and, in a separate condition, between a fixed and variable delay until reinforcement (delay risk). Experiment 1 investigated the impact of water reinforcement and risk dimension when pigeons were in a restrictive budget, where access to water was less than that necessary to maintain current body weight, and a condition where the pigeons had ample access to water. Pigeons exhibited a greater tendency to prefer the variable alternative for delay risk than for amount risk in both restrictive and ample budgets. Varying water budget had no effect on risk preference. Experiment 2 investigated the influence of water reinforcer location while in a restrictive budget, in which reinforcers were delivered to a single location, two distinct locations, or a randomly selected location. With amount risk, pigeons were risk averse when reinforcers were delivered in separate or random locations and were indifferent to risk when delivered to a single location. With delay risk, pigeons were generally risk prone with no effect from reinforcement location. The finding that pigeons were risk averse when reinforcers were delivered to separate locations and were indifferent to risk when delivered to a single location offers a methodological explanation to the inconsistent findings in the literature with amount risk.

Influence of temporal context on value in the multiple-chains and successive-encounters procedures.

This set of studies explored the influence of temporal context across multiple-chain and multiple-successive-encounters procedures. Following training with different temporal contexts, the value of stimuli sharing similar reinforcement schedules was assessed by presenting these stimuli in concurrent probes. The results for the multiple-chain schedule indicate that temporal context does impact the value of a conditioned reinforcer consistent with delay-reduction theory, such that a stimulus signaling a greater reduction in delay until reinforcement has greater value. Further, nonreinforced stimuli that are concurrently presented with the preferred terminal link also have greater value, consistent with value transfer. The effects of context on value for conditions with the multiple-successive-encounters procedure, however, appear to depend on whether the search schedule or alternate handling schedule was manipulated, as well as on whether the tested stimuli were the rich or lean schedules in their components. Overall, the results help delineate the conditions under which temporal context affects conditioned-reinforcement value (acting as a learning variable) and the conditions under which it does not (acting as a performance variable), an issue of relevance to theories of choice.

The rules we choose by.

Hutchinson & Gigerenzer's functional approach to decision making has much in common with behavioral approaches. One of their central points is that "rules-of-thumb" often provide efficient decision strategies, use of which is both rational and generally optimal. We agree, but also caution that the misapplication of rules sometimes leads to non-optimal decisions.

Decision-making: Context matters.

Research and theory in human decision-making has increasingly stressed the importance of the context in which the problem is embedded. This emphasis is consistent with that supported by research of behavior analysts on natural concept formation and in problem solving, as well as in the study of choice. We present data on reasoning problems that further support the role of context in decision-making.

The sunk cost effect in pigeons and humans.

The sunk cost effect is the increased tendency to persist in an endeavor once an investment of money, effort, or time has been made. To date, humans are the only animal in which this effect has been observed unambiguously. We developed a behavior-analytic model of the sunk cost effect to explore the potential for this behavior in pigeons as well as in humans. Each trial started out with a short expected ratio, but on some trials assumed a longer expected ratio part way through the trial. Subjects had the (usually preferable) option of "escaping" the trial if the longer expected ratio had come into effect in order to bring on a new trial that again had a short expected ratio. In Experiments 1 through 3, we manipulated two independent variables that we hypothesized would affect the pigeons' ability to discriminate the increase in the expected ratio within a trial: (a) the presence or absence of stimuli that signal an increase in the expected ratio, and (b) the severity of the increase in the expected ratio. We found that the pigeons were most likely to persist nonoptimally through the longer expected ratios when stimulus changes were absent and when the increase in the expected ratio was less severe. Experiment 4 employed a similar procedure with human subjects that manipulated only the severity of the increase in the expected ratio and found a result similar to that of the pigeon experiment. In Experiment 5, we tested the hypothesis that a particular history of reinforcement would induce pigeons to persist through the longer expected ratios; the results suggested instead that the history of reinforcement caused the pigeons to persist less compared to pigeons that did not have that history.

Behavior-analytic approaches to decision making.

Behavior analysis has much to offer the study of phenomena in the area of judgement and decision making. We review several research areas that should continue to profit from a behavior-analytic approach, including the relative merit of contingency-based and rule-governed instruction of solving algebra and analogy problems, and the role of conditioned reinforcement and the inter-trial interval in a type of Prisoner's Dilemma Game. We focus on two additional areas: (1) the study of base-rate neglect, a notorious reasoning fallacy and (2) the study of the sunk-cost effect, which characterizes ill-conceived investment decisions. In each of these two cases we review studies with humans and pigeons as subjects.

Probability matching: encouraging optimal responding in humans.

Two hundred undergraduate students participated in a repeated-trials binary choice procedure in which choice of one outcome was correct on 75% of trials. Subjects received 192 trials and were divided into five conditions: (1) control; (2) subjects were given the actual probabilities; (3) subjects were told if they did well they could leave early; (4) competition condition; (5) midway through the task subjects were asked to recommend a strategy for another subject. Half of the subjects in each group were told that the best they could do was to be correct on 75% of the trials. This manipulation permitted assessment of the hypothesis that subjects in probability-matching tasks are seeking a strategy that will be correct on 100% of the trials. The results partially confirmed this hypothesis. In addition, two of the variables improved performance significantly (giving probabilities and asking subjects to recommend a strategy). However, while subjects in all groups improved significantly over trials, optimal choice did not occur in this task.

The conjunction effect: new evidence for robustness.

Five studies investigated the conjunction effect (or conjunction fallacy), in which participants report that the conjunction of two events is more rather than less likely than one of the events alone. There was no evidence that feedback or monetary reinforcement for correct answers affected students' performance on conjunction problems. Under some circumstances the context in which the conjunction problem was presented (after questions emphasizing logic or questions emphasizing opinions) affected occurrence of the effect. Location of the conjunction among the statements being rated had a significant effect. The effect occurred with or without a framing description and whether the conjunction consisted of two or three simple statements. However, statements representing the conjunction of three simple statements were (appropriately) judged less likely than those representing the conjunction of two simple statements. The substantial incidence of the effect, even without the descriptive frame and even when incentive and feedback were provided for correct answers, argues for its robustness.

Rules and problem solving: another look.

College students were trained on problems similar to the water jar problems developed by Luchins (1942). Some students were instructed that a particular rule would solve all the problems, others had the same problems but were not instructed about the rule, and a third set of students had a series of novel problems in which no single rule operated throughout. In two experiments students in the instructed rule group not only performed best in training but also performed best when transferred to a condition in which a single novel rule was appropriate. Although results from the set of conditions most similar to those of Luchins suggested that students sometimes inappropriately persisted in rule usage, the overall results suggest that rigidity is not a necessary outcome of instructed problem solving. Indeed, many of the results were consistent with the notion that instructed problem solving is flexible problem solving.

Pigeon parallels to human metacognition.

The target authors make a strong case for parallels between human and nonhuman metacognition. The case may be bolstered by an appeal to the literatures on commitment and self-control and to that on observing behavior.

Choices between segmented and unsegmented schedules and the self-control paradigm.

A concurrent-chains procedure was used to examine choice between a segmented (two- or three-terminal-link segments schedules) and an unsegmented schedule (simple schedule) in terminal links with equal interreinforcement intervals. In most such experiments, preference for the unsegmented schedule has been found, but in a recent study with humans (Alessandri et al., 2010) a reversal in preference was found when, in the segmented schedule, the terminal link segmenting stimulus was presented briefly and closer to food delivery such that the early terminal link stimulus was temporally closer to the food delivery. In Experiment 1, an attempt to replicate this latter effect with pigeons was unsuccessful but this outcome was consistent with an account in terms of a self-control contingency involving conditioned reinforcers. According to this account, the unsegmented alternative consisted of an immediate, smaller presentation of a conditioned reinforcer (i.e., the impulsive, and thus usually the preferred, option in several experiments) and the segmented schedule led to a delayed, larger conditioned reinforcer (i.e., the self-control option). In Experiment 2, a reversal of preference toward the segmented schedule was found when a delay was added to both terminal links between the reinforced initial-link response and the onset of the corresponding terminal link stimulus. This result is consistent with a similar effect found with primary reinforcers in the self-control literature suggesting the utility of self-control as an account of preferences for unsegmented terminal links of concurrent chains schedules.

Regulating the way to obesity: unintended consequences of limiting sugary drink sizes.

OBJECTIVES: We examined whether a sugary drink limit would still be effective if larger-sized drinks were converted into bundles of smaller-sized drinks. METHODS: In a behavioral simulation, participants were offered varying food and drink menus. One menu offered 16 oz, 24 oz, or 32 oz drinks for sale. A second menu offered 16 oz drinks, a bundle of two 12 oz drinks, or a bundle of two 16 oz drinks. A third menu offered only 16 oz drinks for sale. The method involved repeated elicitation of choices, and the instructions did not mention a limit on drink size. RESULTS: Participants bought significantly more ounces of soda with bundles than with varying-sized drinks. Total business revenue was also higher when bundles rather than only small-sized drinks were sold. CONCLUSIONS: Our research suggests that businesses have a strong incentive to offer bundles of soda when drink size is limited. Restricting larger-sized drinks may have the unintended consequence of increasing soda consumption rather than decreasing it.

The role of context in risky choice.

Human choice behavior was assessed in a concurrent-chain schedule, where two equal initial links (IL) each led to a distinct terminal-link (TL). One TL was associated with a fixed ratio schedule of reinforcement, while the other was associated with a bi-valued mixed ratio schedule of reinforcement, whose arithmetic mean equaled the Fixed TL schedule. The fixed component (FR50; FR25; FR5) was arranged to be equal to the alternative mixed component in each condition (FR1/99; FR1/49; FR1/9), and choice behavior was measured by proportion of responses to each IL. In addition, the IL duration varied across conditions (VI 30s; VI 15s; FI 1s). Preference for the mixed option was observed with longer durations (e.g., when IL=VI 30s and TL=FR1/99). Participants were relatively indifferent in other conditions, though the results suggested a monotonic increase in preference as either durations or programmed efforts increased. It is concluded that both choice and the conditioned reinforcement value of the mixed option is contextually based, so that the value of a stimulus correlated with an immediate reward (i.e., FR 1) is enhanced the greater the temporal context in which the FR1 is embedded.