Risks and realities: dyadic interaction between 6-month-old infants and their mothers in opioid maintenance treatment

A number of studies point to methadone exposure in utero as a possible risk factor in the developing mother–infant relationship in the first year of life. This study is part of a larger, national follow-up of 38 infants prenatally exposed to methadone or buprenorphine and 36 comparison, low-risk infants. The aim of the present paper is to assess the quality of mother–infant relationship when the infants are 6 months old. Videotaped mother–infant interactions were rated in a global scale (NICHD). Maternal and infant contributions collapsed into the variables “infant style” and “maternal style” showed that the only factor making significant contribution to the outcome measure “dyadic mutuality” was maternal style. The importance of group membership (exposed versus non-exposed), was reduced when controlling for maternal drug use prior to opioid maintenance treatment (OMT), maternal depression and parenting stress as well as infants’ developmental status and sensory-integrative functions. This suggests that prediction of dyadic mutuality should be based on individual characteristics rather than group characteristics. These results support previous research findings that methadone and buprenorphine use per se does not have direct influence on the quality of early mother–infant relationship, but tailored follow-up procedures targeting drug-free pregnancies and parenting support are beneficial for women in OMT and their children.     

The functional nature of conspiracy beliefs: Examining the underpinnings of belief in the Da Vinci Code conspiracy

Focusing on a contemporary conspiracy theory popularized in the novel The Da Vinci Code (Brown, 2002), we examined the underlying psychological factors and individual differences that may predict belief in conspiracy theories, and assessed such beliefs’ resistance to counterevidence. Our results suggest that belief in the Da Vinci Code conspiracy may be associated with coping with existential threat and death-related anxiety. In addition, the extent to which participants believed in the conspiracy was associated with the endorsement of congruent (New Age spiritual) and competing (Christian religious) beliefs, in opposite directions. Finally, exposure to counterevidence resulted in belief reduction, specifically among more religious participants (i.e. among those endorsing a competing belief system). We suggest that belief in modern conspiracy theories may help individuals attain or maintain a sense of meaning, control, and security.     

Sexual arousal and the pursuit of attractive mating opportunities

From an evolutionary perspective, sexual arousal may function, in part, to motivate the pursuit of attractive mating opportunities. We designed a study to test three aspects of this hypothesis. Several hundred heterosexual men and women completed a short survey about sexual arousal in response to a casual sex mating opportunity. We replicated previous research documenting that men report greater sexual arousal than women in response to a short-term mating opportunity. We argue that it is unlikely that a “downplaying of alternatives” psychology evolved, whereby mated individuals rate opposite-sex targets as less attractive than do unmated individuals, but instead that men and women have a relationship-seeking psychology, motivating them to pursue attractive mating opportunities. The results supported this relationship-seeking psychology rather than a downplaying alternatives psychology. Discussion addresses directions for future research on the motivational properties of sexual arousal.     

TEACHING SELF‐CONTROL WITH QUALITATIVELY DIFFERENT REINFORCERS

This study examined the effectiveness of using qualitatively different reinforcers to teach self‐control to an adolescent boy who had been diagnosed with an intellectual disability. First, he was instructed to engage in an activity without programmed reinforcement. Next, he was instructed to engage in the activity under a two‐choice fixed‐duration schedule of reinforcement. Finally, he was exposed to self‐control training, during which the delay to a more preferred reinforcer was initially short and then increased incrementally relative to the delay to a less preferred reinforcer. Self‐control training effectively increased time on task to earn the delayed reinforcer.     

Effects of pre-trial response requirements on self-control choices by rats and pigeons

Parallel experiments with rats and pigeons examined whether the size of a pre-trial ratio requirement would affect choices in a self-control situation. In different conditions, either 1 response or 40 responses were required before each trial. In the first half of each experiment, an adjusting-ratio schedule was used, in which subjects could choose a fixed-ratio schedule leading to a small reinforcer, or an adjusting-ratio schedule leading to a larger reinforcer. The size of the adjusting ratio requirement was increased and decreased over trials based on the subject's responses, in order to estimate an indifference point-a ratio at which the two alternatives were chosen about equally often. The second half of each experiment used an adjusting-delay procedure-fixed and adjusting delays to the small and large reinforcers were used instead of ratio requirements. In some conditions, particularly with the reinforcer delays, the rats had consistently longer adjusting delays with the larger pre-trial ratios, reflecting a greater tendency to choose the larger, delayed reinforcer when more responding was required to reach the choice point. No consistent effects of the pre-trial ratio were found for the pigeons in any of the conditions. These results may indicate that rats are more sensitive to the long-term reinforcement rates of the two alternatives, or they may result from a shallower temporal discounting rate for rats than for pigeons, a difference that has been observed in previous studies.     

血液透析患者在线血流量与Kt／V及尿素清除率因果关系分析

通过测定维持性透析患者血管通路血流量、Kt/V及尿素清除率(URR),利用自然辨证法中因果关系的复杂性探讨血流量与透析充分性之间的因果关系。选择维持性血液透析患者80例。设定血液透析开始后在线血流量,根据血流量不同分为三组,I组血流量300ml/min,Ⅱ组血流量250ml/min,Ⅲ组血流量200ml/min,计算各组Kt/V值与尿素减少率,观察血流量与Kt/V及尿素减少率之间的相关关系。三组之间Kt/V、URR比较P<0.001,差异均具有显著性;血流量与Kt/V、URR之间呈正相关(r1=0.448,P<0.001;r2=0.413,P<0.001;)随着血流量从300ml/min降到200ml/min,Kt/V、URR分别从1.33±0.33、(68.19±8.86)%降到0.99±0.31、(58.59±13.19)%。血液透析患者的血流量与Kt/V、URR密切相关,两者之间存在因果关系,较高的在线血流量是保证透析充分性的一项重要指标。     

OVERVIEW OF SUPPORTED EMPLOYMENT

This article traces the emergence of supported employment as a result of philosophical changes in expectations for persons with disabilities, based on scientific developments that challenged traditional service-delivery models. Supported employment program characteristics also are reviewed, and the influence of applied behavior analysis is outlined. Finally, areas for future research in supported employment are discussed.     

Incentive theory: IV. Magnitude of reward

Incentive theory is successfully applied to data from experiments in which the amount of food reward is varied. This is accomplished by assuming that incentive value is a negatively accelerated function of reward duration. The interaction of the magnitude of a reward with its delay is confirmed, and the causes and implications of this interaction are discussed.     

Homogeneous chains, heterogeneous chains, and delay of reinforcement

Three pigeons responded on two-component chain schedules in which the required response topography in the initial and terminal links was similar (a homogeneous chain) or dissimilar (a heterogeneous chain). Key-peck responding in the initial link under a variable-interval 60-second (VI 60) schedule produced a terminal link in which, in different conditions, either key pecking or foot treadling was reinforced according to a VI 60 schedule. Multiple VI 60 VI 60 schedules, in which the responses required in the chain schedules were maintained by primary reinforcement in the two components, preceded and followed each type of chain. These multiple schedules were used to ensure that both responses occurred reliably prior to introducing the chain schedule. Key-peck response rates in the initial link of the chain consistently were higher during the homogeneous chain than during the heterogeneous chain. These results illustrate that intervening events during a period separating an operant response from primary reinforcement influence that operant, independently of the delay between the response and reinforcement.     

Choice between single and multiple delayed reinforcers.

Pigeons chose between alternatives that differed in the number of reinforcers and in the delay to each reinforcer. A peck on a red key produced the same consequences on every trial within a condition, but between conditions the number of reinforcers varied from one to three and the reinforcer delays varied between 5 s and 30 s. A peck on a green key produced a delay of adjustable duration and then a single reinforcer. The green-key delay was increased or decreased many times per session, depending on a subject's previous choices, which permitted estimation of an indifference point, or a delay at which a subject chose each alternative about equally often. The indifference points decreased systematically with more red-key reinforcers and with shorter red-key delays. The results did not support the suggestion of Moore (1979) that multiple delayed reinforcers have no effect on preference unless they are closely grouped. The results were well described in quantitative detail by a simple model stating that each of a series of reinforcers increases preference, but that a reinforcer's effect is inversely related to its delay. The success of this model, which considers only delay of reinforcement, suggested that the overall rate of reinforcement for each alternative had no effect on choice between those alternatives.