Control over response number by a targeted percentile schedule: reinforcement loss and the acute effects of d-amphetamine.

Two fixed-consecutive-number-like procedures were used to examine effects of acute d-amphetamine administration on control over response number. In both procedures, rats were required to press the left lever at least once and then press the right lever to complete a trial. The consecutive left-lever presses on each trial comprised a "run." Under the targeted percentile schedule, reinforcement was provided if the current run length was closer to the target length (16) than half of the most recent 24 runs. This differentially reinforced run length while holding reinforcement probability constant at .5. A second group acquired the differentiation under the targeted percentile schedule, but were then shifted to a procedure that yoked reinforcement probability by subject and run length to that obtained under the targeted percentile schedule. The two procedures generated practically identical control run lengths, response rates, reinforcement probabilities, and reinforcement rates. Administration of d-amphetamine disrupted percentile responding to a greater degree than yoked control responding. This disruption decreased reinforcement frequency less in the former than the latter procedure. The similar baseline responding under these two procedures suggests that this difference in sensitivity was due to behavioral adjustments to drug prompted by reduction of reinforcement density in the yoked control but not the percentile schedule. These adjustments attenuate the drug's effects under the former, but not the latter, procedure.     

Parental grief following the death of an infant—a follow-up over one year

The course of parental bereavement during the first year following an infant's death was investigated. Also, the differences in mothers' and fathers' reactions, the differences according to the mothers' occupational role, and the similarities in couples' reactions were studied. From a total sample of 59 families, 13 families answered their questionnaires at all three time points (1, 6 and 13 months), 22 families responded at two time points, and 37 families responded at some point following the loss. Measures relating to anxiety, depression, bodily discomfort, general well being and impact of event were used at the three time points. The results showed that grief, as measured by the different inventories, decreased over time. The decrease was most evident from 6 to 13 months, and most prominent in women. A considerable number of the parents were still actively dealing with the loss all through the first year of bereavement. In most couples the mother reported most distress. Mothers were significantly more depressed than fathers at all time points, and mothers also had significantly higher anxiety and lower general health at 1 and 13 months, and intrusive scores of 1 and 6 months. Women at home evidenced more grief at all three time points than women employed outside the home. A high or low score in one spouse was more strongly correlated with a similar score in the other at 1 and 13 months, than at 6 months. The implications for counselling of parents, with special emphasis on the employment situation of the mother, is emphasized.     

Maintaining Accurate Math Responses In Elementary School Students: The Effects Of Delayed Intermittent Reinforcement And Programming Common Stimuli.

This study examined the effect of delayed reinforcement on digits completed by elementary school children and the effect of programming stimuli common to reinforcement conditions on the maintenance of their performance. Participants exhibited similar levels of responding during intermittent and continuous reinforcement. Responding continued for a number of sessions at similar levels during a maintenance phase that included stimuli present during delayed reinforcement.     

Scale freeness in factor analysis

The notion of scale freeness does not seem to have been well understood in the factor analytic literature. It has been believed that if the loss function that is minimized to obtain estimates of the parameters in the factor model is scale invariant, then the estimates are scale free. It is shown that scale invariance of the loss function is neither a necessary nor a sufficient condition for scale freeness. A theorem that ensures scale freeness in the orthogonal factor model is given in this paper.The authors are grateful for the suggestions of the referees.     

The Impact of Resource Loss and Critical Incidents on Psychological Functioning in Fire-Emergency Workers: A Pilot Study

The relationship between critical incident exposure and resource loss, as conceptualized by Conservation of Resources (COR) theory, in predicting later psychological outcome (e.g., depressive symptoms, anger expression, and state anger) was examined in a sample of 150 fire-emergency workers from a Fire Department in a mid-sized, midwestern city. Additionally, a measure of critical incidents (Critical Incidents Inventory) was developed, and preliminary data on its validity are presented. Results from multiple regression analyses indicated that fire-emergency workers' exposure to critical incidents was directly related to their report of depressive symptoms, outward expression of anger, and state anger. Additionally, results indicated that fire-emergency workers' resource loss was strongly related to their psychological outcome. Results also suggest that resource loss may mediate the impact of critical incident stress exposure on depressive symptoms and the outward expression of anger. These results offer support to applying COR theory to populations under extreme stress.     

Maternal Identity Among Motherless Mothers and Psychological Symptoms in Their Firstborn Children

A variety of detrimental effects are associated with early parental loss. We examined the relationship between childhood maternal loss and maternal identity among 30 motherless mothers and their 26 matched controls, as well as the psychological health of their firstborns. Motherless mothers reported significantly lower maternal identity. However, firstborns of motherless mothers were no more likely to display psychological symptoms than firstborns of comparison mothers. The findings suggest that early maternal loss may not present risk for cross-generational effects.     

胖负面身体自我女性对身体信息注意偏向成分的时间进程：一项眼动追踪研究

虽然目前大量研究基于Vitousek和Hollon (1990)提出的饮食失调认知模型对胖负面身体自我图式者或饮食失调者的注意偏向进行探讨, 但对其注意偏向的成分仍未得出一致结论, 且尚无研究查考其时间进程特点。研究采用更具生态效度的身体图片为实验刺激, 刺激呈现时间2000ms, 采用传统经典的点探测范式与眼动追踪技术结合, 探讨胖负面身体自我女性对身体信息注意偏向成分的时间进程。基于前人的工作(Castellanos et al., 2009; Garner, Mogg, & Bradley, 2006), 研究考察了四个眼动数据：首视点定向偏向分数、首视点潜伏期偏向分数、首视点注视时间偏向以及总注视时间偏向分数, 系统探讨了注意定向、探测时间、最初注意维持/回避以及总体注意维持/回避。眼动数据发现, 胖负面身体自我图式者对不同身体图片存在不同的注意偏向模式, 对胖图片为注意警觉—维持模式, 具体表现为早期加速探测、注意定向, 以及最初的注意维持和总体注意维持; 对瘦图片仅为注意警觉, 具体表现为早期加速探测; 行为数据支持实验组对胖图片的注意维持以及对身体图片的注意脱离困难。该结果部分支持Vitousek和Hollon (1990)的模型, 即负面身体自我图式能够易化对图式一致信息的加工, 而未发现对图式不一致信息的回避或抑制。     

行为决策中的默认效应

默认效应指的是当存在默认选项时, 人们决策时倾向于保留默认选项而不做出改变的一种现象。这种现象广泛存在于器官捐献政策、退休金储蓄计划和消费决策等领域并在这些领域中有巨大的应用价值。目前, 研究者主要从损失规避、质询理论、暗含的推荐和神经心理机制四个方面解释默认效应的形成机制。默认效应还受到努力成本、默认选项的框架和个人经验等因素影响。未来的研究可以从深入探讨默认效应的产生根源、加强其跨文化研究以及拓展其应用领域这三个方面来展开。     

VOUCHER‐BASED CONTINGENT REINFORCEMENT OF SMOKING ABSTINENCE AMONG METHADONE‐MAINTAINED PATIENTS: A PILOT STUDY

This study evaluated the efficacy of a contingency management (CM) intervention to promote smoking cessation in methadone‐maintained patients. Twenty participants, randomized into contingent (n = 10) or noncontingent (n = 10) experimental conditions, completed the 14‐day study. Abstinence was determined using breath carbon monoxide and urine cotinine levels. Contingent participants received voucher‐based incentives for biochemical evidence of smoking abstinence. Noncontingent participants earned vouchers independent of smoking status. Contingent participants achieved significantly more smoking abstinence and longer durations of continuous smoking abstinence than did noncontingent participants. These results support the potential efficacy of using voucher‐based CM to promote smoking cessation among methadone‐maintained patients.