An investigation of DIF mechanisms in the context of differential testlet effects

This study investigated differential item functioning (DIF) mechanisms in the context of differential testlet effects across subgroups. Specifically, we investigated DIF manifestations when the stochastic ordering assumption on the nuisance dimension in a testlet does not hold. DIF hypotheses were formulated analytically using a parametric marginal item response function approach and compared with empirical DIF results from a unidimensional item response theory approach. The comparisons were made in terms of type of DIF (uniform or non‐uniform) and direction (whether the focal or reference group was advantaged). In general, the DIF hypotheses were supported by the empirical results, showing the usefulness of the parametric approach in explaining DIF mechanisms. Both analytical predictions of DIF and the empirical results provide insights into conditions where a particular type of DIF becomes dominant in a specific DIF direction, which is useful for the study of DIF causes.     

Too much anticipation? Large anticipatory adjustments of grasping movements to minimal object manipulations

When humans grasp objects, the grasps foreshadow the intended object manipulation. It has been suggested that grasps are selected that lead to medial arm postures, which facilitate movement speed and precision, during critical phases of the object manipulation. In Experiment 1, it has been tested whether grasp selections lead to medial postures during rotations of a dial. Participants twisted their arms considerably before grasping the dial, even when the upcoming dial rotation was minimal (5°). Participants neither assumed a medial posture at any point during a short rotation, nor did they assume any of the postures involved in short rotations in the opposite direction. Thus, grasp selections did not necessarily lead to specific postures at any point of the object manipulation. Experiment 2 examined the effect of various grasps on the speed of dial rotations. A medial initial grasp resulted in the fastest dial rotations for most rotation angles. Spontaneously selected grasps were more excursed than necessary to maximize dial rotation speed. This apparent overshot might be explained by participants’ sensitive to the variability of their grasps and is in line with the assumption that grasps facilitate control over the grasped object.     

蝴蝶效应与临床思维——一例多器官衰竭患者诊疗反思

多器官衰竭或多器官功能障碍综合征在临床中尤其是急诊及重症监护室内常见,各种病因所致的疾病进展到一定程度均可导致多器官衰竭。在本案例中,一例老年男性患者,以急性腹泻起病,后短时间内进展为多器官衰竭。通过对该例患者病史总结、病理生理机制的探讨,以及对整个诊疗过程的反思,结合“蝴蝶效应”理论,总结出一种新的临床思维,并探讨“蝴蝶效应”理论在对该例患者的诊断、治疗甚至医患沟通方面所起到的作用,以期通过参考该案例,对以后的临床工作起到一定帮助。     

神灵主义医学何以可能?

神灵主义医学,是人类历史上第一个医学范式,拥有一套完整的形而上学信念、方法论体系和解释机制。神灵主义医学已经长期存在,并且在当今世界也广泛存在,这是世界之中的事实,无需争论。站在当代医学发展的前沿回头看,神灵主义医学之所以能够长期指导人类的医疗实践,有其内在原因。人类的大量自限性疾病,为神灵主义医学的成功提供了广泛的归纳支持。安慰剂效应的发现,进一步揭示了神灵主义医学成功的内在可能性。超自然解释,是神灵主义医学治疗失败后,医师给予患者的无助安慰,却为巫医守住了信誉的最后堡垒。     

Effect size,statistical power,and sample size for assessing interactions between categorical and continuous variables

The reporting and interpretation of effect size estimates are widely advocated in many academic journals of psychology and related disciplines. However, such concern has not been adequately addressed for analyses involving interactions between categorical and continuous variables. For the purpose of improving current practice, this article presents fundamental features and theoretical developments for the variance of standardized slopes as a desirable standardized effect size measure for the degree of disparity between several slope coefficients. To estimate the effect size, a consistent and nearly unbiased estimator is described and a simple refinement is emphasized for extreme situations whenever appropriate. The essential problems of power and sample size calculations for testing the equality of slope coefficients are also considered. According to the analytic justification and empirical assessment, the exact approach has a clear advantage over the approximate methods. Both SAS and R computer codes are provided to facilitate practical accessibility of the proposed techniques in interaction studies.     

Longitudinal interplay of young children's negative affectivity and maternal interaction quality in the context of unequal psychosocial resources

Interaction quality and child temperament predict early and later child development. Research hints at transactional interrelations of both aspects but lacks adequate data to examine this assumption. Maternal psychosocial resources are suspected moderators in this context but rarely taken into account. Drawing on data of the German National Educational Panel Study we conducted a cross-lagged panel analysis on the longitudinal interplay of maternal interaction quality and children's negative affectivity at 6–8, 16–18, and 25–27 months and compared mothers with and without accumulated strains. Both variables showed moderate to high structural and rank order stability over time and low but increasing connections. In the case of accumulated stress factors, interaction quality is clearly impaired and high negative affectivity acts as an additional burden while low negative affectivity helps strained mothers to maintain higher interaction quality but only in the first year of life.     

The Faulty Magnitude Detector: Why SNARC‐Like Tasks Cannot Support a Generalized Magnitude System

Do people represent space, time, number, and other conceptual domains using a generalized magnitude system (GMS)? To answer this question, numerous studies have used the spatial‐numerical association of response codes (SNARC) task and its variants. Yet, for a combination of reasons, SNARC‐like effects cannot provide evidence for a GMS, even in principle. Rather, these effects support a broader theory of how people use space metaphorically to scaffold their understanding of myriad non‐spatial domains, whether or not these domains exhibit variation in magnitude.     

The role of response readiness in subliminal visuomotor processes

The present study aims to examine the impact of response readiness on visuomotor processes triggered by subliminal stimuli using a mixed paradigm involving the masked prime paradigm and a foreperiod paradigm. Experiment 1 ensured that response readiness was successfully manipulated in the mixed paradigm. Importantly, Experiment 2 found that the negative compatibility effect (NCE; a behavioral indicator of subliminal visuomotor processes) disappeared and that response time lost its power to modulate the compatibility effect (CE) with reduced response readiness (due to temporal uncertainty). These results of CEs both independent of response latency and across different levels of response latency indicate that response readiness is a prerequisite for obtaining the NCE. The findings suggest that automatic processing of subliminal stimuli is susceptible to top-down control for reducing the interference of irrelevant information, which ensures a high degree of adaptability and flexibility of our cognitive system in interactions with the changing environment.