Exploration of likely engagement with Monetary Contingency Contracts for weight loss: a questionnaire study

Monetary Contingency Contracts (MCCs) are schemes that ask individuals to pledge money that is returned contingent on behaviour change. In relation to weight loss, this study explored likely levels of engagement with MCCs, how much individuals would be willing to pay into an MCC, and how these amounts vary under different contract conditions. Fifty-six individuals with BMI above 25 who were motivated to lose weight were recruited. The majority of participants (87.5%) indicated that they would be willing to engage with weight loss MCCs, but showed more reluctance to subscribe to pair-based MCCs which offered; (a) refunds contingent on the weight loss of a weight loss partner, and (b) ‘all or nothing refunds’ in which no reward is given for any weight loss below the target weight loss goal. This study provides preliminary evidence that individuals motivated to lose weight may be willing to engage with weight loss MCCs. Further research is needed to explore reasons for reluctance to subscribe to MCCs with certain conditions, to inform the design of future experimental studies testing the efficacy of MCCs as part of an intervention for weight loss.     

Embodied information affects judgements about politicians: The impact of haptic weight sensations and hand cleansing

Politicians' characteristics attract voters' attention and dominate impression formation. Thereby, social judgements are deduced from different information being available in a certain situation. The literature suggests that incidental bodily sensations can influence judgement processes. Here, two bodily treatments—the haptic sensation of weight and the act of hand cleansing—simultaneously contribute to judgements about politicians. This study expands previous works by (a) investigating potential interactions of two haptic information cues, (b) providing evidence for the significant role of conceptual closeness between embodied cues and judgement dimensions, (c) showing that hand cleansing leads to harsher moral judgements independently of whether a misconduct has been committed or not, and (d) showing that the familiarity of the target to be judged does not moderate the effect of embodied information. The results demonstrate that judgements can be modulated by basal sensorimotor experiences. We discuss implications and the important issue of result generalisation and replicability.     

Effects of shifts in food reinforcement context on rats’ consumption of concurrently available water or sucrose solution

The purpose of this study was to investigate the effects of signaled transitions from relatively rich to lean conditions of food reinforcement on drinking concurrently available water or sucrose‐sweetened water in rats. Past research demonstrated that these negative incentive shifts produce behavioral disruption in the form of extended pausing on fixed‐ratio schedules. Four male Long‐Evans rats operated on a two‐component multiple fixed‐ratio fixed‐ratio schedule. In one manipulation, the ratio was held constant and the components arranged either a large six‐pellet reinforcer (rich) or small one‐pellet reinforcer (lean). In a second manipulation, the components both produced a one‐pellet reinforcer but differed in terms of the ratio requirement, with the rich and lean conditions corresponding to relatively small and large ratios. In both manipulations, components were pseudorandomly presented to arrange four transitions signaled by retractable levers: lean‐to‐lean, lean‐to‐rich, rich‐to‐rich, and rich‐to‐lean (the negative incentive shift). During experimental conditions, a bottle with lickometer was inserted in the chamber, providing concurrent access either to tap water or a 10% sucrose solution. The negative incentive shift produced considerably more drinking than the other transitions in all rats during both manipulations. The level of drinking was not polydipsic; rather, it appears that the negative incentive shift enhanced the value of concurrently available reinforcers relative to food reinforcement.     

Reinforcement value and fixed‐interval performance

The concept of reinforcement value summarizes the effect of different variables, such as reinforcement delay, reinforcement magnitude, and deprivation level, on behavior. In the present set of experiments, we evaluated the effect of reinforcement devaluation on performance under FI schedules. The literature on timing and reinforcement value suggests that devaluation generates longer expected times to reinforcement than the same intervals trained under control conditions. We devalued reinforcement with delay in Experiments 1A, 1B, and 2, and diminished deprivation in Experiments 3A and 3B. Devaluation reduced response rates, increased the number of one‐response intervals, and lengthened postreinforcement pauses, but had inconsistent effects on other timing measures such as quarter life and breakpoint. The results of delayed reinforcement and diminished deprivation manipulations are well summarized as reinforcement devaluation effects. These results suggest that devaluation may reduce stimulus control. In addition, we argue that the process by which delayed reinforcement affects behavior might also explain some effects observed in other devaluation procedures through the concept of reinforcement value.     

Accuracy in estimating the body weight of self and others: Impact of dietary restraint and BMI

We examined the accuracy of people's estimates of their own body weight and of the body weight of other people. Female undergraduates (n = 132) self-reported their weight, were weighed by the experimenter, and completed a measure of dietary restraint. Participants also viewed 10 photographs of women ranging from underweight to obese and estimated their body weight. Individuals high in dietary restraint underestimated their own weight to a greater extent than those low in dietary restraint, but this effect was accounted for by individual differences in BMI: heavier participants underestimated their weight to a greater extent than leaner participants. Participants also underestimated the weight of heavier targets to a greater extent than they did leaner targets, but the degree of inaccuracy was not related to participants’ dietary restraint or BMI. These findings support the hypothesis that inaccuracies in self-reported weight reflect deliberate misreporting rather than a cognitive or perceptual bias.     

Overconcern with weight and shape is not the same as body dissatisfaction: evidence from a prospective study of pre-adolescent boys and girls

Overconcern with weight and shape and body dissatisfaction have both emerged as significant predictors of disordered eating. However, it is unclear how these constructs relate to each other, and if each has different antecedents and consequences. This study aimed to identify prospective predictors of each construct and to determine their relative importance in predicting dietary restraint and binge eating. Eight- to 13-year-old boys and girls (N = 259) were assessed at baseline and one-year follow-up, using a range of measures that included the Child Eating Disorder Examination. Psychosocial variables predicted overconcern with weight and shape whilst objective weight predicted body dissatisfaction. Body dissatisfaction and weight and shape concern predicted restraint, and weight and shape concern and restraint predicted binge eating. Findings provide support for the theoretical differences between body dissatisfaction and overconcern with weight and shape, and highlight the importance of focusing on specific body image variables.     

Avoidance of timeout from response-independent food: effects of delivery rate and quality

In three experiments, a rat's lever presses could postpone timeouts from food pellets delivered on response-independent schedules. In Experiment 1, the pellets were delivered at variable-time (VT) rates ranging from VT 0.5 to VT 8 min. Experiment 2 replicated the VT 1 min and VT 8 min conditions of Experiment 1 with new subjects. Finally, subjects in Experiment 3 could postpone timeouts from delivery of pellets that differed in quality rather than quantity (unsweetened versus sweetened pellets). In general, response rates and success in avoiding increased as a function of the rate and quality of the pellets. Also, performance efficiency increased as the experiments progressed, that is, the avoidance response occurred later and later in the response-timeout interval. The results support the conclusion that timeout from reinforcement has functional properties similar to those of more commonly studied aversive stimuli (e.g., shock).     

Longitudinal Gender Differences in Objectified Body Consciousness and Weight-Related Attitudes and Behaviors: Cultural and Developmental Contexts in the Transition from College

Longitudinal analysis of objectified body consciousness, body esteem, self-acceptance, and weight-related attitudes and behaviors in young adults (115 women and 49 men), who were undergraduates in 1993, tested hypotheses developed from theory on the social construction of gendered bodies and the developmental contexts of the post-college transition. Gender differences in body surveillance, body shame, and body esteem and the relationships between these persisted, whereas the relationship between body esteem and self-acceptance decreased for women and was similar to men at Wave 2. For both women and men, body surveillance and body shame decreased and body esteem increased over time, even though BMI also increased. Men wanted to lose weight at levels similar to women at Wave 2 and were equally likely to exercise to control weight, but they were less likely than women to diet. These results fit both cohort and age-related changes models of body experience for women and men.     

人工神经网络模型在心理学研究中的运用

人工神经网络是对真实神经元网络的粗略模拟,具有容错性、抗干扰性、高效性等特征,具有学习、记忆等强大的认知功能,因此适宜于心理学许多领域的模拟研究。借助神经网络模型不仅可以模拟和验证以往的实验室研究;还能深入探讨感知、联想、学习和记忆等认知过程的具体发生机理,把握其内在机制;它对探讨内隐记忆、内隐学习等无意识认知过程有极大的启发作用。     

The Quality of Home Environment in Brazil: An Ecological Model

Based on Bronfenbrenner's (1999) ecological perspective, a longitudinal, prospective model of individual differences in the quality of home environment (Home Observation for Measurement of the Environment—HOME) was tested in a sample of 179 Brazilian children and their families. Perinatal measures of family socioeconomic status (SES) and child birth weight had direct effects on HOME at preschool age. As either family SES or child birth weight increased, HOME also increased through diminished emotional distress in the mother a month following childbirth. SES had a negative effect on number of children in the household, which in turn had a long-term negative impact on HOME. Compared to mothers who had reported not to plan their pregnancy, those who did were more likely to have fewer children, to report more spouse support during childbearing, and to show less emotional distress a month after childbirth, all of which also influenced HOME at preschool age. These findings are discussed in light of the broader socio-ecological Brazilian context, with direct implications to clinical practice aimed at improving the quality of home environment.