关于汉字识别加工单位的研究

以眼动为指标的研究发现,汉字识别是以笔画为单位进行加工的。而词识别单位化模型则认为对熟悉词的识别与组成词的字母加工无关。本研究利用汉字具有笔画多少不同及组成部件不等的差别,以独体字或少笔画字为对照,通过三个实验探讨了高频和低频汉字识别的加工单位问题。实验结果表明,高频字笔画数和部件数分别对字识别产生显著影响,低频字似乎只有当笔画数和部件数两种成分都具有一定差异时才表现出识别速度的显著差别。此结果不支持前述的两种模型。提出汉字识别是由多种成分综合作用的结果似更合理。     

Perceptual unit formation in simple motion patterns

The present study investigated the proximal constraints that determine perceptual unit formation under minimal stimulus conditions. Projections of three moving dots, which could form two possible two-dot configurations, were presented to naive observers. In a forced-choice situation, their task was to report which two-dot configuration was perceived as a distinct perceptual unit. The results showed that common motions (arbitrary translations and rigid rotations in the frontoparallel plane) have stronger grouping power as compared to different relative motions (expansions/contractions, or simultaneous expansions/contractions and deformations in the frontoparallel plane). It was found that proximal changes of distances between elements in two-dot structures reduce grouping power. Changes of proximal directions, however, did not affect unit formation in two-dot structures at all. The effect of vector algebraic combinations on grouping power in three-dot strutures was also investigated. Evidently, visual vector analysis splits up motion combinations into their constituents, and in come cases this contributes to additive effects.     

Matching, maximizing, and the behavioral unit: concurrent reinforcement of response sequences.

Pigeons pecked two keys in a probability matching situation in which four two-peck sequences were intermittently reinforced: left-left, left-right, right-left and right-right. In Phase 1, relative reinforcement rate was varied with respect to the first response of a sequence: reinforcers were differentially assigned for left-left and left-right sequences as opposed to right-left and right-right sequences. The second response of reinforced sequences occurred equally on the left and right keys across conditions. In Phase II, relative reinforcement rate was varied for sequences that involve an alternation as opposed to those that did not. The relative outputs of the different sequences matched the relative reinforcement rates for the different sequences in both phases. Relative response rates for key pecks did not always match relative reinforcement rates. The intertrial interval separating responses was varied in both phases; increases in the intertrial interval affected the relative frequency of different sequences. The results demonstrate that response sequences acted as functional units influencing choice and thus support a structural account of choice. At the same time, the matching of relative sequence proportion and relative reinforcement rate supports a matching account.     

ICU医护沟通与协作的现状与思考

许多研究表明ICU医护之间的沟通与协作存在重大问题,特别是在临终决策中存在分歧。护士的作用经常被忽视。加强医护之间的沟通与协作有助于提高医疗质量并改善医护、患者及家庭满意度。许多旨在改善沟通与协作的措施已经证实有效并可应用于临床实践,并应对此进行更深一步的研究。     

Strategic flexibility in response preparation: Effects of cue validity on reaction time and pupil dilation

This study examined the ability of participants to strategically adapt their level of response preparation to the predictive value of preparatory cues. Participants performed the finger-precuing task under three levels of cue validity: 100, 75 and 50% valid. Response preparation was indexed by means of reaction time (RT) and pupil dilation, the latter providing a psychophysiological index of invested effort. Results showed a systematic increase in RT benefits (generated by valid cues) and RT costs (generated by invalid cues) with increments in the predictive value of cues. Converging with these behavioural effects, pupil dilation also increased systematically with greater cue validity during the cue-stimulus interval, suggesting more effortful response preparation with increases in cue validity. Together, these findings confirm the hypothesis that response preparation is flexible and that it can be strategically allocated in proportion to the relative frequency of valid/invalid preparatory cues.     

Principles for Designing Randomized Preventive Trials in Mental Health: An Emerging Developmental Epidemiology Paradigm

An emerging population-based paradigm is now being used to guide the design of preventive trials used to test developmental models. We discuss elements of the designs of several ongoing randomized preventive trials involving reduction of risk for children of divorce, for children who exhibit behavioral or learning problems, and for children whose parents are being treated for depression. To test developmental models using this paradigm, we introduce three classes of design issues: design for prerandomization, design for intervention, and design for postintervention. For each of these areas, we present quantitative results from power calculations. Both scientific and cost implications of these power calculations are discussed in terms of variation among subjects on preintervention measures, unit of intervention, assignment, balancing, number of pretest and posttest measures, and the examination of moderation effects.     

Family-Based Intervention with High-Risk Infants and Their Families

A model of family-based intervention for high-risk infants hospitalized in the neonatal intensive care unit and their families is presented. The theoretical underpinnings, principles, and nature of the intervention are described. The adaptation of the model from a clinical–research demonstration project to a clinical consultation service is highlighted, with particular emphasis on the practical application of the model. Domains of the intervention include infant behavior, family organization and functioning, caregiving environment, and home discharge/community resources. Three case illustrations are provided to demonstrate the breadth of the intervention and how it can be individualized based upon the presentation of the infant and family.     

Role adjustment as the unit of analysis for researching child development during the transition to school

While child development is well-recognized as a complex process which could hardly be decomposed into separate lines or domains in contemporary psychological theories, the decomposition approach is widely used in empirical studies. Based on the cultural-historical theory, this study argues for adopting the unit of analysis as a way to bridge this gap, and finds “role adjustment” as a suitable unit to analyse child development during the transition to school. The case of a 5-year-old second-generation Chinese Australian child's transition to school (with a total of 34 h of observation and 5 h of interview) is presented to verify its feasibility and to illustrate how it could be achieved in a research practice. The case study demonstrates that a child's role adjustment is in essence a process of transforming his/her role system, during which his/her major roles, the relation of the major roles, as well as his/her role-taking patterns change as a whole, and by tracing a child's role adjustment trajectory, how the child is learning and developing, what difficulties he/she encounter, and why these difficulties appear become clear.     

Assessing unit-price related remifentanil choice in rhesus monkeys

Given a commodity available at different prices, a unit-price account of choice predicts preference for the cheaper alternative. This experiment determined if rhesus monkeys preferred remifentanil (an ultra-short-acting micro-opioid agonist) delivered at a lower unit price over a higher-priced remifentanil alternative (Phases 1 and 3). Choice between equal-priced alternatives also was assessed (Phase 2). A discrete-trials procedure was arranged in which three monkeys chose between two remifentanil alternatives by responding on one of two levers. Different prices were arranged by manipulating drug dose (0.3 and 0.1 microg/kg/injection) and/or the ratio requirement. Monkeys usually chose the larger-dose alternative even when it was more expensive. Only when unit prices were relatively high (e.g., large response requirements) did monkeys choose the cheaper (or equally priced) smaller-dose alternative. Employing larger doses (0.9 and 0.3 microg/kg/injection) attenuated the larger-dose preference. The results demonstrate that choice was not determined simply by unit price. An alternative model that employs demand-function analysis to generate choice predictions is proposed.