学习支持对基于计算机模拟的发现学习的影响

研究了针对发现活动的意义性的解释性支持 (IS)、针对其系统逻辑性的实验性支持 (ES)以及学习者的推理能力对基于模拟的科学发现学习的影响。设计开发了关于浮力的模拟软件 ,被试为北京十四中初二学生 80名 ,采用 2 (有 /无IS)× 2 (有 /无ES)× 3(推理能力 )的混合实验设计。结果发现 ,推理能力在原理性知识、直觉性理解测验以及学习者所设计实验的质量上有显著的主效应。IS在原理性知识和灵活应用测验上有显著的主效应。ES与推理能力在原理性知识测验上有显著的交互作用 ,ES在学习者所设计实验的质量上有显著的主效应。这一结果说明 ,发现活动的意义性和系统逻辑性对基于模拟的发现学习有重要的制约作用 ,应该针对这两个侧面设计相应的学习支持     

Adjectives Modulate Sensorimotor Activation Driven by Nouns

We performed three experiments to investigate whether adjectives can modulate the sensorimotor activation elicited by nouns. In Experiment 1, nouns of graspable objects were used as stimuli. Participants had to decide if each noun referred to a natural or artifact, by performing either a precision or a power reach-to-grasp movement. Response grasp could be compatible or incompatible with the grasp typically used to manipulate the objects to which the nouns referred. The results revealed faster reaction times (RTs) in compatible than in incompatible trials. In Experiment 2, the nouns were combined with adjectives expressing either disadvantageous information about object graspability (e.g., sharp) or information about object color (e.g., reddish). No difference in RTs between compatible and incompatible conditions was found when disadvantageous adjectives were used. Conversely, a compatibility effect occurred when color adjectives were combined with nouns referring to natural objects. Finally, in Experiment 3 the nouns were combined with adjectives expressing tactile or shape proprieties of the objects (e.g., long or smooth). Results revealed faster RTs in compatible than in incompatible condition for both noun categories. Taken together, our findings suggest that adjectives can shape the sensorimotor activation elicited by nouns of graspable objects, highlighting that language simulation goes beyond the single-word level.     

A pilot investigation on the effects of combination transcranial direct current stimulation and speed of processing cognitive remediation therapy on simulated driving behavior in older adults with HIV

Cognitive impairments seen in people living with HIV (PLWH) are associated with difficulties in everyday functioning, specifically driving. This study utilized speed of processing cognitive remediation therapy (SOP-CRT) with transcranial direct current stimulation (tDCS) to gauge the feasibility and impact on simulated driving. Thirty PLWH (M_age = 54.53, SD = 3.33) were randomly assigned to either: sham tDCS SOP-CRT or active tDCS SOP-CRT. Seven indicators of simulated driving performance and safety were obtained. Repeated measures ANOVAs controlling for driver’s license status (valid and current license or expired/no license) revealed a large training effect on average driving speed. Participants who received active tDCS SOP-CRT showed a slower average driving speed (p = 0.020, d = 0.972) than those who received sham tDCS SOP-CRT. Non-significant small-to-medium effects were seen for driving violations, collisions, variability in lane positioning, and lane deviations. Combination tDCS SOP-CRT was found to increase indices of cautionary simulated driving behavior. Findings reveal a potential avenue of intervention and rehabilitation for improving driving safety among vulnerable at-risk populations, such as those aging with chronic disease.     

Grounding by Attention Simulation in Peripersonal Space: Pupils Dilate to Pinch Grip But Not Big Size Nominal Classifier

Grammatical categories represent implicit knowledge, and it is not known if such abstract linguistic knowledge can be continuously grounded in real‐life experiences, nor is it known what types of mental states can be simulated. A former study showed that attention bias in peripersonal space (PPS) affects reaction times in grammatical congruency judgments of nominal classifiers, suggesting that simulated semantics may include reenactment of attention. In this study, we contrasted a Chinese nominal classifier used with nouns denoting pinch grip objects with a classifier for nouns with big object referents in a pupil dilation experiment. Twenty Chinese native speakers read grammatical and ungrammatical classifier‐noun combinations and made grammaticality judgment while their pupillary responses were measured. It was found that their pupils dilated significantly more to the pinch grip classifier than to the big object classifier, indicating attention simulation in PPS. Pupil dilations were also significantly larger with congruent trials on the whole than in incongruent trials, but crucially, congruency and classifier semantics were independent of each other. No such effects were found in controls.     

On the determination of defect dipoles from atomistic simulations using periodic boundary conditions

By solving the problem of a periodic distribution of point defects in general anisotropic media, we give an alternative, more direct proof, of the relatively recent procedure that extracts dipole tensors from the stress acting on the cell of atomistic simulations performed under periodic boundary conditions. Moreover, we show that naive superposition of individual defect fields is not a solution of the problem, though correction terms can be identified; as a byproduct, analysis of the latter allows us to reveal a spurious contribution to the elastic interaction energy as calculated in current literature procedures, that therefore must be subtracted in order to obtain correct results.     

Influence of twist boundary on deformation behaviour of 〈1 0 0〉 BCC Fe nanowires

Molecular dynamics simulations revealed significant difference in deformation behaviour of 〈1?0?0〉 BCC Fe nanowires with and without twist boundary. The plastic deformation in perfect 〈1?0?0〉 BCC Fe nanowire was dominated by twinning and reorientation to 〈1?1?0〉 followed by further deformation by slip mode. On the contrary, 〈1?0?0〉 BCC Fe nanowire with a twist boundary deformed by slip at low plastic strains followed by twinning at high strains and absence of full reorientation. The results suggest that the deformation in 〈1?0?0〉 BCC Fe nanowire by dislocation slip is preferred over twinning in the presence of initial dislocations or dislocation networks. The results also explain the absence of extensive twinning in bulk materials, which inherently contains large number of dislocations.     

The influence of attention allocation and age on intersection accidents

Many severe accidents occur in urban areas. As part of the research project UR:BAN, this study investigated the causes of driver errors (e.g., inadequate attention allocation) in urban areas when turning left at intersections. As intersection accidents are especially difficult for older drivers, differences between older and younger drivers were examined as well. In a first step, accident protocols of left turn crashes with pedestrians and bicyclists were analysed in detail, since they are the most dangerous ones. Characteristics of the oncoming traffic and the location of crossing bicyclists and pedestrians were identified as possible causes. Accordingly, critical scenarios were implemented in a static driving simulator, varying the characteristics of the oncoming traffic, the direction and location of crossing vulnerable road users. These factors were examined in a within-subject design, with two different aged groups of participants (12 aged 20–35 y, 12 aged 65+ y; between-subjects factor).The results revealed that the presence of the oncoming traffic, which was assumed to capture the drivers’ attention, did not lead to more accidents with vulnerable road users. However, this may be because many drivers waited until the oncoming traffic had passed. Unexpectedly, older drivers had fewer accidents. This may be explained by the more cautious behaviour of older drivers, who drove significantly slower and waited significantly longer at the stop line before turning. Further analyses showed that a more cautious behaviour, independently of the age, predicted accident avoidance better than attention allocation. From these results, warning systems for younger and older drivers, especially for those not driving cautious, need to be developed. This idea will be tested in future studies introducing different warning concepts.     

Power Analysis for the Likelihood-Ratio Test in Latent Markov Models: Shortcutting the Bootstrap p-Value-Based Method

The latent Markov (LM) model is a popular method for identifying distinct unobserved states and transitions between these states over time in longitudinally observed responses. The bootstrap likelihood-ratio (BLR) test yields the most rigorous test for determining the number of latent states, yet little is known about power analysis for this test. Power could be computed as the proportion of the bootstrap p values (PBP) for which the null hypothesis is rejected. This requires performing the full bootstrap procedure for a large number of samples generated from the model under the alternative hypothesis, which is computationally infeasible in most situations. This article presents a computationally feasible shortcut method for power computation for the BLR test. The shortcut method involves the following simple steps: (1) obtaining the parameters of the model under the null hypothesis, (2) constructing the empirical distributions of the likelihood ratio under the null and alternative hypotheses via Monte Carlo simulations, and (3) using these empirical distributions to compute the power. We evaluate the performance of the shortcut method by comparing it to the PBP method and, moreover, show how the shortcut method can be used for sample-size determination.     

Eye Movements Reveal Mental Looking Through Time

People often make use of a spatial “mental time line” to represent events in time. We investigated whether the eyes follow such a mental time line during online language comprehension of sentences that refer to the past, present, and future. Participants' eye movements were measured on a blank screen while they listened to these sentences. Saccade direction revealed that the future is mapped higher up in space than the past. Moreover, fewer saccades were made when two events are simultaneously taking place at the present moment compared to two events that are happening in different points in time. This is the first evidence that oculomotor correlates reflect mental looking along an abstract invisible time line during online language comprehension about time. Our results support the idea that observing eye movements is likely to “detect” invisible spatial scaffoldings which are involved in cognitively processing abstract meaning, even when the abstract meaning lacks an explicit spatial correlate. Theoretical implications of these findings are discussed.