Variations in explicitly unpaired training are differentially effective in producing conditioned inhibition

To evaluate a contingency interpretation of conditioned inhibition (CI), rats were given “explicity unpaired” training in which the locus and duration of a CS within the inter-US (shock) interval were systematically manipulated for different groups. Summation and retardation tests in Experiment 1 indicated that stronger CI resulted from both a backward and a trace CS than from a midlocus CS of equal or greater duration. Complementing these findings, the same tests in Experiment 2 showed that, by comparison with novel-stimulus controls, CI developed to a trace CS but not to a mid-locus CS, nor to a trace CS that was accompanied by an immediate signal for the US. These findings argue against a contingency interpretation of CI and favor a contiguity interpretation stressing the short-term rehearsal of stimulus events. Such rehearsal of the US allows a backward CS, but not a mid-locus CS with an extended US-CS interval, to be discriminated as a signal for nonreinforcement, and thus to develop as a conditioned inhibitor. Similarly, excitatory conditioning to the memory trace of a CS allows the nominal trace CS to develop as a signal for nonreinforcement, and thus as a conditioned inhibitor, but not when its memory trace is overshadowed by another CS that immediately precedes the US. In short, the development of CI is facilitated when excitation is mediated by the memorial processing of either the US or a discrete CS for the US rather than by contextual cues.     

Effects of acute endurance,strength, and coordination exercise interventions on attention in adolescents: A randomized controlled study

ObjectivesThe aim of this study was to compare three different modes of an acute bout of exercise – endurance, strength, and coordination – in their effects on adolescents' attention.DesignThis was a preregistered, prospective, randomized intervention study with four groups and two distinct measurement occasions.MethodEighty adolescent students aged 15–18 years were randomized to one of three exercise intervention groups (endurance, strength, coordination) or to a non-exercise, control group. The exercise interventions lasted for 25 min. The random assignment to the study groups was stratified according to participants' age and gender. Before and after the exercise intervention, all participants completed the revised d2-test of attention. A 4 × 2 repeated measures ANOVA with contrast-coded test was used as the main analysis method.ResultsAttentional test performance increased from before to after the exercise intervention for all exercise groups, as compared with the control group. The three exercise groups improved equally and did not differ in their attentional scores after the intervention.ConclusionsAn acute bout of exercise was in general beneficial for adolescent students' attention, while the mode of the provided exercise training was not decisive. School directors and teachers are encouraged to incorporate exercise-related breaks into their school plan.     

Continuous and discrete latent structure models for item response data

Relations are examined between latent trait and latent class models for item response data. Conditions are given for the two-latent class and two-parameter normal ogive models to agree, and relations between their item parameters are presented. Generalizationss are then made to continuous models with more than one latent trait and discrete models with more than two latent classes, and methods are presented for relating latent class models to factor models for dichotomized variables. Results are illustrated using data from the Law School Admission Test, previously analyzed by several authors.     

医学伦理学概念之探究

医学伦理学的概念看起来很简单,一般情况下人们便习以为常地接受了作为应用规范伦理学的一个分支的科学地位,而忽视了医学对医学伦理学所起的作用。本文认为：医学伦理学的具体内容是医学科技与伦理道德两因素相互作用的产物,对其相互作用的形式和产物的具体分析和总结便可构成这门学科的理论体系。     

Coping, competence, and aggression prevention: Part 2. Universal school-based prevention

Coping—competence theory yields a structural model of the development of persistent aggression in which current challenge encounters determine future life outcomes and competence. Driven by this model, universal, school-based prevention programs would aim in multiple ways to promote prosocial coping among high-risk, resilient, and advantaged youth from kindergarten through high school. Expected benefits of prosocial coping would include: less aggressive behavior, fewer adverse life outcomes (e.g., school dropout, police arrest, teen pregnancy, conduct, mood, and substance-use disorders), and a more competent self-definition and social reputation. Five stages are described that may prove useful in creating prosocial schools and neighborhoods supportive of youth in transition away from antisocial coping and deviant peers.     

Realism,instrumentalism, and the intentional stance

One of Dennett's principal arguments for an instrumentalistic construal of intentional attributions (e.g., attributions of belief, etc.) is that such attributions are environment relative. I argue that one can and should adopt a realist perspective toward such attributions, but accommodate their environmental relativity by treating intentional properties as relational properties. By doing so one acquires a useful perspective on experimental cognitive psychology; in particular, one can overcome the temptation to treat ecological accounts and information processing accounts as incompatible alternatives and come to see them as mutually supportive. Treating intentional properties as relational may be counter-intuitive, but I provide examples of how other sciences have had to treat what seem to be intrinsic properties as relational.     

The effects of situational performance constraints on intrinsic motivation and satisfaction: The role of perceived competence and self-determination

Situational performance constraints, task interest, and pay contingencies were manipulated in a laboratory study in order to investigate the cognitive mechanisms associated with the previously observed detrimental effects of constraints on affective task reactions. It was hypothesized that feelings of task competence and self-determination would account for both the direct and the interactive effects of constraints on motivation and satisfaction. The results of the study indicated that despite the fact that participants' performance was being constrained and they were aware of these constraints, the mere presence of the constraints alone failed to result in lower levels of satisfaction or motivation on a proofreading task. Post hoc analyses suggested that the constraints, in fact, led to negative affective task reactions when they also reduced participants' feelings of competence and self-determination. Interestingly, participants' generalized locus of control was associated with such effects. Internals tended to maintain stronger feelings of competence and self-determination than externals in the presence of constraints, thereby also maintaining greater motivation and satisfaction.     

A signal detection framework for the evaluation of probabilistic forecasts

In this paper I formulate an approach for evaluating probabilistic forecasts in terms of signal detection theory. Signal detection theory provides a powerful perspective for this type of problem, and a rich empirical background including methodological tools as well as an extensive body of research in many domains. I propose procedures which emphasize the maximization of expected utility for the decision maker who uses the forecasts. Further, I suggest approaches to obtaining indices of calibration and resolution within this framework. I also present arguments that the proposed indices will exhibit the same basic properties as do decompositions of Brier's (1950, Monthly Weather Review, 78, 1–3) mean probability score. However, the properties may be reflected in different ways, and hence, the present methods may lead to different conclusions about forecasting ability. Finally, I argue that the use of an expected utility loss function makes this approach more appropriate for practical applications as well as for theoretical research than other procedures with more arbitrary loss functions.     

The effects of feedback consistency and feedback favorability on self-perceived task competence and perceived feedback accuracy

The present study, employing a 2 × 2 true-experimental design and regression analyses assessed the main and interactive effects of feedback consistency (consistent vs inconsistent), and feedback favorability (acceptable vs superior), for feedback given at two time periods on measures of perceived feedback accuracy and self-perceived task competence. Among the study's findings were that (a) the perceived accuracy of feedback at the second period was a function of the favorability of feedback received at the first time period, (b) the self-perceived task competence levels of subjects were jointly determined by the favorability of feedback received at both time periods, and (c) the perceived accuracy of feedback was a function of its consistency. Organizational implications of the study's results are offered.