Addendum to Killeen's (2019) Bidding for Delayed Rewards

Killeen (2019) portrayed an intimate relation between diverse economic indices, in particular compensation functions, discount functions, and demand functions. The article bemused some experts, however, by its counterintuitive prediction of an increase in the amount bid as the delay increased. Furthermore, the article failed to provide an explicit treatment of the small–soon versus large–late choice paradigm, to cite several papers that provided precedent for the current work, and to demonstrate the adequacy of his expenditure functions for data on purchasing decisions. These shortcomings are remedied in the current note, and some additional extensions offered.     

Does a smartphone on the desk drain our brain? No evidence of cognitive costs due to smartphone presence in a short-term and prospective memory task

It has recently been shown that the mere presence of one’s own smartphone on the desk impairs working memory performance. The aim of this study was to follow up on this important finding by assessing the effect of smartphone presence (present on the desk vs. absent from the desk) on different memory functions (short-term memory and prospective memory), and by further examining the moderating role of individual differences in smartphone dependency and impulsiveness. We found no overall effect of smartphone presence on short-term and prospective memory performance. There was a moderating effect for prospective memory: Performance was better when the smartphone was absent versus present for participants with low smartphone dependency. In light of the absence of an overall effect of smartphone presence on memory functions, our results show that previous findings of impairments in working memory due to smartphone presence do not generalize to other domains of memory capacity.     

跨期选择中偏好反转的心理机制

通过直接测量近期和远期选择中备选项激活的情绪、间隔的时间知觉及对备选项金额差异和时间间隔的重视程度,以探究跨期选择中偏好反转产生的心理机制。结果表明：（1）近期选择中,备选项激活的情绪强度差异显著,而远期选择中两者的差异不显著;（2）近期和远期选择中,情绪强度差异和时间知觉差异能够预测偏好反转的发生。研究结果支持了偏好反转的情绪激活差异假说和时间知觉差异假说。     

The sign effect,systematic devaluations and zero discounting

The sign effect is the steeper discounting of gains compared to losses. However, we see a greater sign effect on an individual level compared to an aggregate level. In this experiment, we compare discounting of gains and losses on an individual and aggregate level, to explore further details about when and to what extent human adults discount. Thirty-one participants went through a computer-based choice-task procedure of hypothetical monetary gains and losses. The results show clear qualitative differences between discounting of gains and losses, adding empirical data to support the sign effect. The results also support previous findings that show that aggregate and individual results do not always correspond. Further, the within-subject details showing zero discounting or nonsystematic changes concerning losses, replicate earlier studies suggesting that discounting of gains and losses involve different reinforcing contingencies. The present study expands on this research area by including verbal reports, supplementing details about the unobserved reinforcing contingencies. Implications of research on discounting may indicate how to deal with decision-making challenges and might shed light on why predictions about complex decision making sometimes fail.     

Extent of food restriction affects probability but not delay-based decision-making

Rodent studies on decision-making often use food rewards and food-restrict subjects in order to motivate performance. However, food restriction has widespread effects on brain and behavior, which depend on factors including extent of restriction and feeding schedule. These factors are well recognized for their effects on motivation, but may also cause effects on decision-making independent of motivation. We examined how the degree of weight-based food restriction in rats influenced decision-making on the probability and delay discounting tasks. Additionally, we examined how the method of food restriction (consistent amount vs. time constrained feeding schedule) influenced decision-making. Our results showed that the degree of weight-based food restriction significantly altered probability, but not delay discounting, and that these effects were not entirely explainable by differences in motivation. Additionally, the method of food restriction did not significantly influence discounting when animals were within the same range of weight-based restriction. Together, our findings suggest that the degree of food restriction may modulate the neural circuitry responsible for selective aspects of decision-making related to probability. Further, these data support the need for tight control and reporting of weight and feeding in studies relying on food restriction, and suggest that the effects of food restriction may be broader than previously considered.     

A ratio scale for social distance

Choosing a larger–later reward over a smaller–sooner reward may be thought of as altruism toward one's future self. A question that arises in this connection is: What is the relation between delay and social discounting? To begin to answer this question, social and delay discount functions need to be comparable. Delay is ordinarily measured on a ratio scale (time), which allows for meaningful division and addition. Social distance is ordinarily measured on an ordinal scale (rank order of social closeness). To convert social distance to a ratio scale we use a psychophysical distance function obtained via magnitude estimation (Stevens, 1956). The distance functions obtained are well described by a power function (median exponent = 1.9); we show how they may be used to rescale ordinal to ratio social discount functions.     

Pigeons' discounting of probabilistic and delayed reinforcers

Pigeons' discounting of probabilistic and delayed food reinforcers was studied using adjusting-amount procedures. In the probability discounting conditions, pigeons chose between an adjusting number of food pellets contingent on a single key peck and a larger, fixed number of pellets contingent on completion of a variable-ratio schedule. In the delay discounting conditions, pigeons chose between an adjusting number of pellets delivered immediately and a larger, fixed number of pellets delivered after a delay. Probability discounting (i.e., subjective value as a function of the odds against reinforcement) was as well described by a hyperboloid function as delay discounting was (i.e., subjective value as a function of the time until reinforcement). As in humans, the exponents of the hyperboloid function when it was fitted to the probability discounting data were lower than the exponents of the hyperboloid function when it was fitted to the delay discounting data. The subjective values of probabilistic reinforcers were strongly correlated with predictions based on simply substituting the average delay to their receipt in each probabilistic reinforcement condition into the hyperboloid discounting function. However, the subjective values were systematically underestimated using this approach. Using the discounting function proposed by Mazur (1989), which takes into account the variability in the delay to the probabilistic reinforcers, the accuracy with which their subjective values could be predicted was increased. Taken together, the present findings are consistent with Rachlin's (Rachlin, 1990; Rachlin, Logue, Gibbon, & Frankel, 1986) hypothesis that choice involving repeated gambles may be interpreted in terms of the delays to the probabilistic reinforcers.     

Critical appraisal of the discussion on delay discounting by Bailey et al. and Stein et al.: A scientific proposal for a reinforcer pathology theory 3.0

Delay discounting is one of the most studied phenomena in Psychology in the last decades. Recently, it has been proposed as a transdiagnostic variable accounting for several psychopathological problems. A review of current practices and clinical application (Bailey et al., 2021) and a response article (Stein et al., 2022) have been recently published. Despite both of them being stimulating, the articles raise issues needing further discussion. The first part of the present article critically appraises both publications by highlighting their strengths/limitations and offers an alternate perspective that clarifies some theoretical issues and allows new lines in research. In the second part, one of these new lines of research is presented by describing a research proposal based on the analysed critiques and current developments in both psychopathology and addiction research. This article contributes to the discussion on delay discounting suggesting alternative interpretations and future studies to improve theoretical models.     

Molar functional relations and clinical behavior analysis: implications for assessment and treatment

The experimental analysis of behavior has identified several molar functional relations that are highly relevant to clinical behavior analysis. These include matching, discounting, momentum, and variability. Matching provides a broader analysis of how multiple sources of reinforcement influence how individuals choose to allocate their time and offers an empirical rationale for reducing problem behavior by increasing adaptive behavior. Discounting highlights the functional relations that affect self-control. Momentum specifies the variables responsible for persistence in challenging situations. Variability characterizes a functional dimension of behavior that is essential for learning and problem solving. These concepts have important implications for clinical practice and research. A selective review of these concepts is presented, and their implications for assessment and treatment are discussed with two goals: to inform basic scientists about the relevance of their work and to invite clinical behavior analysts to broaden the conceptual basis for their work.