Drug effects on repeated acquisition: comparison of cumulative and non-cumulative dosing

Pigeons acquired a different four-response chain each session by responding sequentially on three keys in the presence of a sequence of four colors. The response chain was maintained by food presentation under a fixed-ratio schedule. Errors produced a brief timeout but did not reset the chain. Each day there were four 15-minute sessions, with a 10-minute inter-session interval. Cumulative dose-effect curves for phencyclidine, pentobarbital, and d-amphetamine were obtained by giving an injection before each of the four sessions; successive injections increased the cumulative dose in equally spaced logarithmic steps. For comparison, non-cumulative doses of each drug (i.e., doses not preceded by other doses on the same day) were also tested. As the cumulative dose of each drug increased, the overall response rate decreased, the percent errors increased, and there was less within-session error reduction (acquisition). With phencyclidine and pentobarbital, the rate-decreasing and error-increasing effects tended to be greater with a non-cumulative dose than with the corresponding cumulative dose. In contrast, with d-amphetamine, the effects were considerably greater with the cumulative doses. The results indicate that although the cumulative-dosing procedure saved a substantial amount of time in determining dose-effect curves, there were quantitative differences in effects between cumulative and non-cumulative doses.     

The microanalysis of fixed-interval responding

The fixed-interval schedule of reinforcement is one of the more widely studied schedules in the experimental analysis of behavior and is also a common baseline for behavior pharmacology. Despite many intensive studies, the controlling variables and the pattern of behavior engendered are not well understood. The present study examined the microstructure and superstructure of the behavior engendered by a fixed-interval 5- and a fixed-interval 15-minute schedule of food reinforcement in the pigeon. Analysis of performance typical of fixed-interval responding indicated that the scalloped pattern does not result from smooth acceleration in responding, but, rather, from renewed pausing early in the interval. Individual interresponse-time (IRT) analyses provided no evidence of acceleration. There was a strong indication of alternation in shorter-longer IRTs, but these shorter-longer IRTs did not occur at random, reflecting instead a sequential dependency in successive IRTs. Furthermore, early in the interval there was a high relative frequency of short IRTs. Such a pattern of early pauses and short IRTs does not suggest behavior typical of reinforced responding as exemplified by the pattern found near the end of the interval. Thus, behavior from clearly scalloped performance can be classified into three states: postreinforcement pause, interim behavior, and terminal behavior.     

Adverse caregiving in early life: The trauma and deprivation distinction in young children

Knowledge and understanding about the impact of cumulative adverse experiences on the health and wellbeing of children, adolescents, and adults has rapidly expanded over the past 30 years. Despite the invaluable attention and support this proliferation has drawn to the importance of early childhood experiences, we believe that it is time to move beyond broad indices of risk and toward more specific and individualized understanding of how risk exposures are linked to clinical outcomes in young children. Within infant and early childhood mental health, there is a need for greater specificity in linking adverse caregiving experiences in early life to psychopathology in children. We highlight a framework distinguishing experiences of trauma from experiences of deprivation and use the examples of posttraumatic stress disorder and reactive attachment disorder to demonstrate how greater specificity in our understanding of early adverse caregiving can lead to more accurate and targeted diagnosis and treatment for young children. Both researchers and clinicians benefit from an approach to gain a greater appreciation of the links between specific types of experiences and outcomes in the children that we serve.     

Steps and pips in the history of the cumulative recorder

From its inception in the 1930s until very recent times, the cumulative recorder was the most widely used measurement instrument in the experimental analysis of behavior. It was an essential instrument in the discovery and analysis of schedules of reinforcement, providing the first real-time analysis of operant response rates and patterns. This review traces the evolution of the cumulative recorder from Skinner's early modified kymographs through various models developed by Skinner and his colleagues to its perfection in the 1950s, and then into the 1960s when it proliferated as different scientific instrument companies began marketing their own models of the cumulative recorder. With the rise of digital computers, the demise of the cumulative recorder as a scientific instrument was inevitable; however, the value of the cumulative record as a monitoring device to assess schedule control of behavior continues. The cumulative recorder remains, along with the operant conditioning chamber, an icon of Skinner's approach to psychology.     

累积生态风险与高职生学习倦怠：消极自我图式和网络成瘾的中介作用

采用累积生态风险问卷、消极自我图式问卷、网络成瘾问卷以及学习倦怠问卷对湖南省4所高职院校的664名高职生进行调查,考察累积生态风险与高职生学习倦怠的关系以及消极自我图式、网络成瘾的中介作用。结果发现:(1)高职生累积生态风险、消极自我图式、网络成瘾和学习倦怠均呈显著正相关;(2)高职生累积生态风险对学习倦怠的直接效应和间接效应均显著。间接效应包括了三条路径:通过消极自我图式的中介作用、通过网络成瘾的中介作用以及通过消极自我图式和网络成瘾的链式中介作用。这一结论有助于理解累积生态风险对学习倦怠的作用机制,为降低高职生的学习倦怠提供参考建议。     

Secret médical en santé au travail

The occupational physicians are obliged, like any doctor, to respect the ethical obligations imposed on their profession, including in the exercise of the missions specific to occupational medicine and contained in the Labor Code. The occupational physician is not isolated and works in a multidisciplinary team of a health service at work. He must communicate with other health professionals, but also with employers, representative bodies of staff. Medical confidentiality holds a special place in the triangular relationship between the occupational physician, the employee and the employer. The medical practice in the field of occupational health requires that many provisions of the Labor Code be followed, including the respect of the secret of manufacture and the position of advising employers and employees. The occupational physician must communicate with the employer in order to best achieve his mission, but in practice, it may be difficult for the occupational doctor to make his recommendations heard to improve the working conditions of employees without power, when he cannot argue his opinions on medical information.     

无关言语对汉字短时记忆系列回忆的影响*

采用视觉呈现字表和听觉呈现无关言语方式,探讨在字表项目保持期间阻止被试复述情况下,不同呈现位置的无关言语对汉字短时记忆系列回忆的影响。在字表保持期间,采用计算任务进行分心作业。实验结果发现：(1)无关言语对汉字短时记忆系列回忆成绩存在显著影响;(2)在字表保持期间阻止被试进行复述消除了字表呈现期间呈现无关言语对回忆成绩产生的干扰效应;(3)汉字短时记忆系列回忆成绩表现出系列位置效应。实验结果没有完全支持客体情节记忆模型。