Force and rate relations in responding during variable-interval reinforcement

Four rats responded on one-minute variable-interval schedules with several variations in peak-force of response required for food reinforcement. Measures of peak force and rate were taken for the responses, which were the downward exertions of force against a static force-transducing operandum. The analysis distinguished responses, a generic class of measured behavior, from criterion responses, an operationally specified subclass required for reinforcement. Absolute rate of response showed no systematic change, but the rate of responses meeting a newly required criterion of peak-force invariably increased through changes in the absolute rate of response, the relative-frequency distributions of peak force, or some combination of both. The relative frequency of responses meeting an elevated force criterion during variable-interval reinforcement exceeded that maintained with the same criterion with continuous reinforcement. The requirement of more effortful responding for reinforcement does not necessarily reduce response rate. Conformity of the behavior to the requirement for reinforcement is the salient effect.     

Positive reinforcement and the elimination of reinforced responses

Key pecking was maintained on a fixed-interval schedule while either a differential-reinforcement-of-not-responding or a fixed-time schedule was imposed simultaneously. The lower the time parameter of the not-responding schedule, the lower was the response rate. Similar effects occurred with the fixed-time schedule, if the pigeons had experience with reinforcement for not responding. Otherwise the effects were less orderly, to the extent that rate could reach maximum with the lowest-valued fixed-time schedule. The not-responding and the response-independent schedules had similar effects on rate in experienced pigeons only when the time parameter or nominal frequency of food presentation was considered. When considered in terms of obtained frequency of food presentation, reinforcement of not responding produced larger decrements in rate than did the fixed-time schedule.     

Stimulus control of differential-reinforcement-of-low-rate responding

Five pigeons were given single-stimulus training on an 8-sec differential-reinforcement-of-low-rate schedule followed by steady-state generalization training using 12 wavelength stimuli. Three birds had a high percentage of reinforced responses on the training schedule and flat generalization gradients of total responses. The birds with fewer reinforced responses had much steeper generalization gradients. Generalization gradients plotted as a function of both stimulus wavelength and interresponse time showed that for most birds, stimulus control was restricted to responses with long interresponse times. Responses with very short interresponse times were not under stimulus control and there was some evidence of inhibitory control of short interresponse times. Interresponse-times-per-opportunity functions, plotted as a function of stimulus wavelength, showed that stimulus wavelength controlled the temporal distribution of responses, rather than the overall rate of response. The data indicate that the differential-reinforcement-of-low-rate schedule generates several response categories that are controlled in different ways by wavelength and time-correlated stimuli, and that averaging responses regardless of interresponse-time length obscures this control.     

Alternative response training, differential reinforcement of other behavior, and extinction in squirrel monkeys (Saimiri sciureus)

In Experiment I, (a) extinction, (b) extinction plus reinforcement of a discrete alternative response, and (c) differential reinforcement of other behavior were each correlated with a different stimulus in a three-component multiple schedule. The alternative-response procedure more rapidly and completely suppressed behavior than did differential reinforcement of other behavior. Differential reinforcement of other behavior was slightly more effective than extinction alone. In Experiment II, reinforcement of specific alternative behavior during extinction and differential reinforcement of other behavior were used in two components, while one component continued to provide reinforcement for the original response. Once again, the alternative-response procedure was most effective in reducing responding as long as it remained in effect. However, the responding partially recovered when reinforcement for competing behavior was discontinued. In general, responding was less readily reduced by differential reinforcement of other behavior than by the specific alternative-response procedure.     

Analytic practice: Convergences and divergences1

The author discusses current convergences and divergences concerning analytic practice. After presenting a clinical vignette that can be understood differently according to different theoretical approaches, he discusses Wallerstein’s proposal of a common ground in psychoanalysis and suggests that the present state of the art indicates that psychoanalysis is a pluralistic discipline, with different ways of training and practising it, and that the main challenge is to improve our ability to listen to and to learn from different approaches.     

国内外医学专业杂志发表医学人文相关文章情况分析

总结分析了201 2年1月～2013年5月国外4种医学专业杂志(BMJ、JAMA、LANCET和NEJM)医学人文相关文章的发表情况,并与国内4种知名医学专业杂志(《中华医学杂志》、《中国实用内科杂志》、《中华内科杂志》和《中华外科杂志》)发表的医学人文类文章的情况进行对比分析,结果发现,国外医学专业杂志医学人文类文章比重较大,而且涉及的领域较广,包括医疗卫生政策管理、医学社会学、对患者及医生的人文关怀、医疗风险告知和医疗差错告知的文章.而国内与国外杂志相比存在较大差距.     

A note on computing Louis’ observed information matrix identity for IRT and cognitive diagnostic models

Using Louis’ formula, it is possible to obtain the observed information matrix and the corresponding large-sample standard error estimates after the expectation–maximization (EM) algorithm has converged. However, Louis’ formula is commonly de-emphasized due to its relatively complex integration representation, particularly when studying latent variable models. This paper provides a holistic overview that demonstrates how Louis’ formula can be applied efficiently to item response theory (IRT) models and other popular latent variable models, such as cognitive diagnostic models (CDMs). After presenting the algebraic components required for Louis’ formula, two real data analyses, with accompanying numerical illustrations, are presented. Next, a Monte Carlo simulation is presented to compare the computational efficiency of Louis’ formula with previously existing methods. Results from these presentations suggest that Louis’ formula should be adopted as a standard method when computing the observed information matrix for IRT models and CDMs fitted with the EM algorithm due to its computational efficiency and flexibility.     

Modeling Asymmetry in the Time–Distance Relation of Ordinal Personality Items

In analyzing responses and response times to personality questionnaire items, models have been proposed which include the so-called “inverted-U effect.” These models predict that response times to personality test items decrease as the latent trait value of a given person gets closer to the attractiveness of an item. Initial studies into these models have focused on dichotomous personality items, and more recently, models for Likert-type scale items have been proposed. In all these models, it is assumed that the inverted-U effect is symmetrical around 0, while, as will be explained in this article, there are substantive and statistical reasons to study this assumption. Therefore, in this article, a general inverted-U model is proposed which accommodates two sources of asymmetry between the response times and the attractiveness of the items. The viability of this model is demonstrated in a simulation study, and the model is applied to the responses and response times of the Temperament and Character Inventory–Revised, covering a broad range of personality dimensions.     

自发性知觉经络反应中产生刺麻感和积极情绪的原因

自发性知觉经络反应(autonomous sensory meridian response,ASMR)是指在特定的视听刺激下,某些个体(ASMR敏感个体)在头皮后部、颈部乃至全身体验到一种令人极度愉快和放松的刺麻感的现象。其中,刺麻感的产生可能是个体大脑中负责感觉和肌肉运动的脑区高度激活引起的; 而与情绪和奖赏有关脑区的高度激活以及心率和呼吸频率的下降可能是产生愉快和放松感的重要原因。相比普通个体,ASMR敏感个体具有较高的神经质、共情特质、感觉受暗示性和特质正念。这可能说明ASMR敏感个体的感觉敏感性较高,情绪稳定性较弱,且比较关注自己身体的内外感受。这些个性特质可能导致ASMR敏感个体对某些视听刺激中所包含的一些感觉和情绪信息更加敏感,对其反应也更加强烈。目前,ASMR已经被用于抑郁,压力,失眠和慢性疼痛等的临床治疗以及商业广告之中。但ASMR可能会干扰个体的执行功能,在认知控制需求较高的情景下应尽量避免接触ASMR刺激。     

Mindfulness-based programs,perceived stress and well-being at work: The preferential use of informal practices

IntroductionOrganizations which engage in the promotion of well-being are likely to prevent mental health issues in workers. Mindfulness-based interventions offer new perspectives to increase well-being at work. However, the issue of finding time and framework to practice at work is important. Recent studies suggested that informal mindfulness practices could be useful in reducing stress and increasing well-being.ObjectiveThe present study aimed to study how the duration and type of mindfulness practice may enhance employees’ well-being.MethodA multi-method (qualitative and quantitative), controlled pre/post design study (N = 72) was conducted to collect data about the type of preferred mindfulness practices used during an 8-week MBSR program, and to analyse the effects of the program on employees’ well-being. Number of sessions, number of days of practice, and practice time per day were used as moderators.ResultsParticipants reported a preferential use of brief, informal practices. Employees who followed the MBSR program reported higher levels of well-being compared to the wait-list control group (η² = .194). Those who preferentially used informal practices showed the same increase in well-being as those who reported preferentially using formal practices. The number of days of practice did not moderate the effect of the intervention on well-being.ConclusionBrief and informal mindfulness practices appear to be a promising means of increasing well-being in everyday life. Further research is needed to compare an 8-week mainly informal mindfulness-based program to a classical MBSR program to identify whether informal practices may be sufficient to increasing employees’ well-being.