Impaired inhibition of prepotent motor tendencies in Friedreich ataxia demonstrated by the Simon interference task

Friedreich ataxia (FRDA) is the most common of the genetically inherited ataxias. We recently demonstrated that people with FRDA have impairment in motor planning - most likely because of pathology affecting the cerebral cortex and/or cerebello-cortical projections. We used the Simon interference task to examine how effective 13 individuals with FRDA were at inhibiting inappropriate automatic responses associated with stimulus-response incompatibility in comparison with control participants. Participants had to respond to arrow targets according to two features which were either congruent or incongruent. We found that individuals with FRDA were differentially affected in reaction time to incongruent, compared with congruent stimuli, when compared with control participants. There was a significant negative correlation between age of onset and the incongruency effect, suggesting an impact of FRDA on the developmental unfolding of motor cognition, independent of the effect of disease duration. Future neuroimaging studies will be required to establish whether this dysfunction is due to cerebellar impairment disrupting cerebro-ponto-cerebello-thalamo-cerebral loops (and thus cortical function), direct primary cortical pathology, or a possible combination of the two.     

Causality, criticality, and reading words: distinct sources of fractal scaling in behavioral sequences

The finding of fractal scaling (FS) in behavioral sequences has raised a debate on whether FS is a pervasive property of the cognitive system or is the result of specific processes. Inferences about the origins of properties in time sequences are causal. That is, as opposed to correlational inferences reflecting instantaneous symmetrical relations, causal inferences concern asymmetric relations lagged in time. Here, I integrate Granger-causality with inferences about FS. Four simulations illustrate that causal analyses can isolate distinct FS sources, whereas correlational techniques cannot. I then analyze three simultaneous sequences of responses from a database of word-naming trials. I find that two, or perhaps three, distinct sources account for the presence of FS in these sequences, but FS is not a general property of the system. This suggests that FS arises due to the properties of a limited number of identifiable psychological and/or neural processes. Finally, I reanalyze a previously published dataset of acoustic frequency spectra using the new tools. The causality/criticality combination introduced here offers a new important perspective in the study of cognition.     

The mediating effects of time structure on the relationships between time management behaviour,job satisfaction,and psychological well‐being

This article examined the relationship between time structure and Macan's process model of time management. This study proposed that time structure—‘appraisal of effective time usage’—would be a more parsimonious mediator than perceived control over time in the relationship between time management behaviours and outcome variables, such as job satisfaction and psychological well‐being. Alternative structure models were compared using a sample of 111 university students. Model 1 tested Macan's process model of time management with perceived control over time as the mediator. Model 2 replaced perceived control over time by the construct of time structure. Model 3 examined the possibility of perceived control over time and time structure as being parallel mediators of the relationships between time management and outcomes. Results of this study showed that Model 1 and Model 2 fitted the data equally well. On the other hand, the mediated effects were small and partial in both models. This pattern of results calls for reassessment of the process model.     

Further evaluation of response-independent delivery of preferred stimuli and child compliance

The effect of a fixed-time (FT) schedule involving the delivery of preferred stimuli prior to the issuance of a low-probability instruction was evaluated with 2 young children with autism. The FT schedule was introduced according to a reversal design with 3 target instructions, 1 for the first child and 2 for the second child. Compliance increased for 2 of the 3 cases. A high-probability instruction sequence and guided compliance were implemented for the second instruction targeted for 1 child, with compliance increasing with guided compliance.     

An evaluation and comparison of time-out procedures with and without release contingencies

A common recommendation for implementing time‐out procedures is to include a release contingency such that the individual is not allowed to leave time‐out until no problem behavior has occurred for a specific amount of time (e.g, 30 s). We compared a fixed‐duration time‐out procedure to a release contingency time‐out procedure with 4 young children (3‐ and 4‐year‐olds) using a reversal and multielement design. Results demonstrated that both time‐out procedures were effective at reducing problem behavior outside time‐out, problem behavior occurred in time‐out during both procedures, and problem behavior in time‐out was not predictive of problem behavior outside time‐out.     

Preference as a function of active interresponse times: a test of the active time model

In this article, we describe a test of the active time model for concurrent variable interval (VI) choice. The active time model (ATM) suggests that the time since the most recent response is one of the variables controlling choice in concurrent VI VI schedules of reinforcement. In our experiment, pigeons were trained in a multiple concurrent similar to that employed by Belke (1992), with VI 20-s and VI 40-s schedules in one component, and VI 40-s and VI 80-s schedules in the other component. However, rather than use a free-operant design, we used a discrete-trial procedure that restricted interresponse times to a range of 0.5-9.0 s. After 45 sessions of training, unreinforced probe periods were mixed with reinforced training periods. These probes paired the two stimuli associated with the VI 40-s schedules. Further, the probes were defined such that during their occurrence, interresponse times were either "short" (0.5-3.0 s) or "long" (7.5-9.0 s). All pigeons showed a preference for the stimulus associated with the relatively rich VI 40-s schedule--a result mirroring that of Belke. We also observed, though, that this preference was more extreme during long probes than during short probes--a result predicted by ATM.     

不同留守时间下儿童公正感的特点及其与主观幸福感的关系

采用公正感问卷,生活满意度问卷和积极/消极情感问卷,选取5-8年级565名留守儿童和640名非留守儿童进行调查,探讨不同留守时间下儿童公正感的特点及其与主观幸福感(生活满意度,积极情感,消极情感)的关系。结果表明:(1)不同留守时间下,儿童的公正感得分存在边缘显著性差异(p=0.055);(2)总体上,留守儿童的公正感得分显著低于非留守儿童。具体讲,留守4年半以下和4年半～10年,儿童的公正感得分均显著低于非留守儿童;留守10年以上的儿童公正感得分和非留守儿童不存在差异;(3)各留守时间下,公正感对于生活满意度、积极情感均具有显著地正向预测作用,但对于消极情感仅在特定时间具有显著负向预测作用。表明,留守时间是影响儿童公正感特点及其和主观幸福感关系的重要因素。     

《黄帝内经》时间医学思想对急性心肌梗死时间节律的解释

《黄帝内经》“天人相应”理论比较完备地奠定了中医关于人体生物节律知识的基础,强调人体自然节律与四季日月昼夜节律之间的密切关系。在急性心肌梗死发病呈现显著的时间节律特征,以中医时间学理论进行解释,充分掌握急性心肌梗死发病的规律性,指导高危人群合理作息,减少急性心梗的发生。