儿童行为抑制的生理机制研究述评

行为抑制指儿童不愿意接近陌生刺激,并带有害羞、恐惧和焦虑等消极情绪的气质类型,具有中等程度的稳定性和特定生理基础,对儿童日后情绪和行为发展具有较大影响。与非行为抑制个体相比,在特定的刺激条件下,行为抑制个体的杏仁核、纹状体和右前额区域的激活水平可能较高,心率和可的松水平也倾向于较高。目前,研究者已结合行为和生理学方法来探讨行为抑制的生理机制,取得了一些重要的进展。但是,也存在一些问题有待于进一步探讨。     

The limits of objective assessment of medical practice

Medical work is increasingly being subjected to objective assessment as those who pay for it seek to grasp the quality of that work and how best to improve it. While objective measures have a role in the assessment of health care, I argue that this role is currently overestimated and that no human practice such as medicine can be fully comprehended by objective assessment. I suggest that the character of practices, in which formalizations are combined with judgment, requires that valid assessment involve the perspective of the skilled practitioner. Relying exclusively on objective measures in assessing health care will not only distort our assessments of it but lead to damage as the incentives of health care workers are directed away from the important aspects of their work that are not captured by objective measures.

Neurocognitive Functioning in AD/HD,Predominantly Inattentive and Combined Subtypes

The Predominantly Inattentive (PI) and Combined (CB) subtypes of AD/HD differ in cognitive tempo, age of onset, gender ratio, and comorbidity, yet a differentiating endophenotype has not been identified. The aim of this study was to test rigorously diagnosed PI, CB, and typical children on measures selected for their potential to reveal hypothesized differences between the subtypes in specific neurocognitive systems (anterior vs. posterior attentional systems) and processes (arousal vs. activation). Thirty-four CB and 26 PI children meeting full DSM-IV criteria for subtype both in school and at home, without confounding reading disability or emotional disorder, were enrolled along with 20 typically developing children. Neurocognitive functions measured included attention, inhibitory control, working memory, learning, and executive functions. Tasks included the Stroop, Wisconsin Card Sorting Test, Continuous Performance Test (CPT). Buschke Selective Reminding Test, ad the Tower of London (TOL), as well as instruments developed by Posner and Sternberg, and tasks assessing the impact on reaction time of [corrected] varying preparatory intervals and stimulus/response complexity. After co-varying for IQ, subtypes differed primarily on measures of impulsivity during tests of vigilance (CPT) and executive function (TOL), with the CB group showing greater impulsivity than both other groups. In addition, the PI group showed worse performance than CB and control groups on the WISC-III Processing Speed Index. Whether analyzed with or without an IQ co-variate, there was no support in the data for hypothesized differences between subtypes in functioning of the anterior vs. posterior attentional systems, nor in involvement of arousal vs. activation processes. The results indicate that the PI and CB subtypes are best differentiated by ratings, observations and tests of cognitive tempo and behavioral impulsivity. Neuropsychological methods have yet to identify critical neuropsychological [corrected] substrates of these differences.     

Effects of imagery training on cognitive performance and use of physiological measures as an assessment tool of mental effort

The effectiveness of motor imagery training on cognitive performance was examined and the physiological mechanisms involved in the contribution of mental practice to motor learning were considered. The subject's mental effort during motor imagery was assessed by using psychophysiological measures and particularly eye blink activity as an 'indirect' measurement of subjects' attention. An electronic flight simulation program (Multiple Attribute Task Battery--MATB) was used to assess performance. Twenty healthy volunteers participated in the study divided in two groups: the control group and the imagery-training group. The subjects of the imagery group were asked for additional imagery training. The subjects of the actual performing group were asked additionally to passively observe the task in order to have equal time of exposure to the task. Performance scores and physiological parameters such as heart rate, respiratory rate, eye blinking activity and muscular activity were recorded during all sessions. The results revealed significantly higher performance level of the imagery-training group than the control group. Heart rate and respiratory rate significantly increased during imagery sessions compared to rest. A slight electromyographic activity was observed during the imagination of movement. Our findings support the notion that mental practice improves motor performance in a task where spatiotemporal or dynamic control of the action is highly required. The effects of mental practice on motor performance could be explained by the existence of a top-down mechanism based on the activation of a central representation of the movements, since the vegetative activation during motor imagery seems to be centrally controlled.     

Objective work–nonwork conflict: From incompatible demands to decreased work role performance

Research on work–nonwork conflict (WNC) is based on the assumption that incompatible demands from the work and the nonwork domain hamper role performance. This assumption implies that role demands from both domains interact in predicting role performance, but research has been largely limited to main effects. In this multi-source study, we analyze the incompatibility of demands by testing the interaction of work and nonwork demands on task performance and organizational citizenship behavior (OCB). The sample consisted of 61 employees of a German hospital and we used three independent sources of data: self-ratings of work demands, partner-ratings of nonwork demands, and colleague-ratings of performance. Results from hierarchical regression analyses revealed an interaction effect of work and nonwork demands on OCB, but not on task performance. We conclude that people maintain their effort invested in task-related aspects of the job even when conflicts between work and nonwork demands exist, but that they reduce their investment in activities that are perceived as more marginal and extra-role.     

Do procedures really matter when rewards are more important? A Pakistani perspective on the effects of distributive and procedural justice on employee behaviors

Introduction

Researchers agree that procedural justice and distributive justice interact so that high procedural fairness reduces the negative consequences of distributive unfairness.

Improving performance by anchoring movement and “nerves”

Golf’s governing bodies’ recent decision to ban all putting styles “anchoring one end of the club against the body” bridges an important practical problem with psychological theory. We report the first experiment testing whether anchoring provides technical and/or psychological advantage in competitive performance. Many “greats” of professional golf from Arnold Palmer and Jack Nicklaus to Tiger Woods have argued against anchoring, believing that it takes “nerves” out of competitive performance and therefore artificially levels the playing field. To shed more light on the issue, we tested participants’ performance with anchored and unanchored putters under low and high pressure when controlling for the putter length. We found no statistically significant evidence for a technical advantage due to anchoring but a clear psychological advantage: participants who anchored their putters significantly outperformed unanchored counterparts under high, but not low, pressure. Results provide tentative evidence for the ban’s justification from a competitive standpoint. However, before any definite conclusions can be made, more research is needed when using high-level golfers.     

Bilingualism and age are continuous variables that influence executive function

We analyzed the effects of bilingualism and age on executive function. We examined these variables along a continuum, as opposed to dichotomizing them. We investigated the impact that bilingualism and age have on two measures of executive control (Stroop and Flanker). The mouse-tracking paradigm allowed us to examine the continuous dynamics of the responses as participants completed each trial. First, we found that the Stroop effect was reduced with younger age and higher levels of bilingualism; however, no Bilingualism by Age interaction emerged. Second, after controlling for baseline, the Flanker effect was not influenced by bilingualism or age. These results support the notion that bilingualism is one way of enhancing some aspects of executive function – specifically those related to the Stroop task – across the adult life span. In sum, different levels of bilingualism, and different ages, result in varying degrees of executive function as measured by the Stroop task.     

Relations between a laboratory-based sustained attention task and traffic violations in an Iranian sample of drivers

The role of cognitive abilities regarding driver behavior is crucially important in the occurrence of traffic violations and preventing tragic motor vehicle collisions. Sustained attention is one cognitive ability that may contribute to safe driving behavior. The present study investigated the relation between sustained attention and traffic violations. One hundred and one Iranian male drivers (age: M = 37.17, SD = 8.37) with at least 2 years driving experience voluntarily participated in the study. Participants were categorized into two groups based on the number of driving rule violations they committed over the last 2 years (n = 48 clean record, n = 53 violators). Sustained attention was measured by performance on the Conjunctive Continuous Performance Task (CCPT). Four CCPT performance measures were computed: (1) Mean reaction time for correct responses (M-RT); (2) standard deviation of reaction times for correct responses (SD-RT); (3) percent of omission errors (failure to respond to target stimulus); (4) percent of commission errors (identification of a non-target stimulus as target). Results showed after controlling for age and education, there was a significant group difference on M-RT, indicating that individuals with no traffic violations had faster reaction times as compared to those who had 1 or more traffic violations. No effect of group on any of the other outcomes was present after correcting for alpha inflation. When assessing the effect of age and education, education was significantly related to average reaction time and percent of omission errors. No significant effect of age was apparent. Findings suggest cognitive function, specifically sustained attention measured with a laboratory-based measure, may be associated with safe driving behavior.