DO INFANTS SHOW GENERALIZED IMITATION OF GESTURES? II. THE EFFECTS OF SKILLS TRAINING AND MULTIPLE EXEMPLAR MATCHING TRAINING

The determinants of generalized imitation of manual gestures were investigated in 1‐ to 2‐year‐old infants. Eleven infants were first trained eight baseline matching relations; then, four novel gestures that the infants did not match in probe trials were selected as target behaviors. Next, in a generalized imitation test in which matching responses to baseline models were intermittently reinforced, but matching responses to target models were not eligible for reinforcement, the infants matched baseline models but not the majority of their target behaviors. To ensure their failure to match the target behaviors was not due to motor constraints, the infants were trained, in a multiple‐baseline procedure, to produce the target responses under stimulus control that did not include an antecedent model of the target behavior. There was no evidence of generalized imitation in subsequent tests. When the infants were next trained to match each target behavior to criterion (tested in extinction) in a multiple‐baseline‐across‐behaviors procedure, only 2 infants continued to match all their targets in subsequent tests; the remaining infants matched only some of them. Seven infants were next given mixed matching training with the target behaviors to criterion (tested in extinction); they subsequently matched these targets without reinforcement when interspersed with trials on which matching responses to baseline models were intermittently reinforced. In repeat tests, administered at 3‐week intervals, these 7 children (and 2 that did not take part in mixed matching training) continued to match most of their target behaviors. The results support a trained matching account, but provide no evidence of generalized imitation, in 1‐ to 2‐year‐old infants.     

CONTINGENCY CONTRACTING WITH DELINQUENTS: EFFECTS OF A BRIEF TRAINING MANUAL ON STAFF CONTRACT NEGOTIATION AND WRITING SKILLS

A brief training manual was developed for the purpose of teaching child-care workers to contingency contract with delinquent youths living in residential care facilities. The manual was designed to require minimal supplementary training by a professional. In Experiment 1 a multiple baseline design was used to assess the effect of the manual on 4 child-care workers' contract negotiation and writing behaviors. Experiment 2 consisted of four A-B systematic replications. Behaviors were assessed within the context of analogue training simulations and generalization tests with delinquent youths. Results from the analogue simulations indicated that the manual was successful in increasing both types of behaviors to a level of proficiency that equaled or surpassed that of behaviorally trained graduate students, and results from the generalization tests indicated that the child-care workers were able to apply their newly acquired contracting skills with delinquent youths. Procedural reliability varied across child-care workers, but was usually high.     

Effects of Pointing Rate and Availability of Visual Feedback on Visual and Proprioceptive Components of Prism Adaptation

The withdrawal of vision of the arm during a manual aiming task has been found to result in a large increase in aiming error, regardless of the amount of practice in normal vision before its withdrawal. In the present study, the authors investigated whether the increase in error reflects the domination of visual afferent information over the movement representation developed during practice to the detriment of other sources of afferent information or whether it reflects only transformation errors of the location of the target from an allocentric to an egocentric frame of reference. Participants (N = 40) performed aiming movements with their dominant or nondominant arm in a full-vision or target-only condition. The results of the present experiment supported both of those hypotheses. The data indicated that practice does not eliminate the need for visual information for optimizing movement accuracy and that learning is specific to the source or sources of afferent information more likely to ensure optimal accuracy during practice. In addition, the results indicated that movement planning in an allocentric frame of reference might require simultaneous vision of the arm and the target. Finally, practice in a target-only condition, with knowledge of results, was found to improve recoding of the target in an egocentric frame of reference.     

Effects of Target Presentation Time,Recall Delay,and Aging on the Accuracy of Manual Pointing to Remembered Targets

The issues addressed in 2 experiments in which 10 younger and 10 older adults participated were (a) whether the retention of a target location in memory for motor control purposes would be facilitated by an increase in target presentation time; (b) whether increasing the recall delay since the last exposure to the target would have deleterious effects on aiming accuracy or variability, or both; and (c) whether those effects would be mediated by aging. The results revealed that there is a short-lived (< 1 s) visual representation of target location. In addition, the results suggested that the nature of that representation dictates a movement strategy favoring higher peak movement velocity. None of the effects reported in the present study was affected by age, suggesting that the coding and retrieving processes of target location in memory for motor control purposes are not affected by age.     

Development of Multiple Movement Representations With Practice: Specificity Versus Flexibility

The question addressed in the present experiment was whether an individual who practices a task under different conditions of afferent information develops different movement representations, each of which is based on the most accurate source of afferent information for movement control. In Experiment 1, participants (N = 23) performed a manual aiming movement in a target-only condition for 520 trials before performing in a normal vision condition for an equivalent amount of practice. Control groups performed all practice trials in either a normal vision or a target-only condition. The results revealed that the movement representation developed in the initial (target-only) practice phase remained accessible for movement planning and control. The results of Experiment 2 indicated, however, that participants did not maintain such a representation when their initial practice in the target-only condition was reduced (40 or 160 trials) before they had extensive practice in normal vision. Those results indicate that extensive practice in a target-only and then in a normal vision condition enables an individual to plan and control his or her movement on the basis of the most efficient source of available afferent information. Because visual afferent information provides optimal information for ensuring movement accuracy, however, if initial practice in the target-only condition is only modest or moderate it is likely that that information source will progressively dominate all other sources of afferent information for movement planning and control.     

Psychologists' perspectives on the diagnostic classification of mental disorders: Results from the WHO‐IUPsyS Global Survey

This study examined psychologists' views and practices regarding diagnostic classification systems for mental and behavioral disorders so as to inform the development of the ICD‐11 by the World Health Organization (WHO). WHO and the International Union of Psychological Science (IUPsyS) conducted a multilingual survey of 2155 psychologists from 23 countries, recruited through their national psychological associations. Sixty percent of global psychologists routinely used a formal classification system, with ICD‐10 used most frequently by 51% and DSM‐IV by 44%. Psychologists viewed informing treatment decisions and facilitating communication as the most important purposes of classification, and preferred flexible diagnostic guidelines to strict criteria. Clinicians favorably evaluated most diagnostic categories, but identified a number of problematic diagnoses. Substantial percentages reported problems with crosscultural applicability and cultural bias, especially among psychologists outside the USA and Europe. Findings underscore the priority of clinical utility and professional and cultural differences in international psychology. Implications for ICD‐11 development and dissemination are discussed.     

Numeric comparison in a visually-guided manual reaching task

Nearly all studies on perception and cognition have used discrete responses to infer internal cognitive processes. In the current study, we demonstrate that visually-guided manual reaching can provide new opportunities to access internal processes over time. In each trial, participants were required to compare a single digit Arabic number presented on the center square with the standard, 5. Participants were asked to reach and touch one of three squares on the screen with their index finger while their hand movement trajectories were recorded: the left square for 1-4, the center for 5, and the right for 6-9. Direct evidence for an analogue representation of numbers was found in early as well as in later portions of hand trajectories, showing systematic shifts in position for small differences in numerical magnitude.     

工作设计对知识型员工和体力工作者的差异化影响：一个现场准实验研究

虽然泰勒主义似乎已被工作设计所替代, 但是近来有些学者们注意到工作设计并未起到预期的效果。该研究旨在探讨工作类型作为一个重要的调节变量, 影响着这两种观点的适用性。通过一个纵向现场准实验设计研究, 结果证实了工作类型的调节作用, 即工作丰富化对知识型员工和体力工作者工作产出的影响存在显著差异。这一结果表明, 泰勒主义和工作设计思想并无优劣之分。该文的研究结果对人力资源管理实践的发展, 具有一定的现实指导意义。