Safety implications of co-locating road signs: A driving simulator investigation

BackgroundAs road complexity increases the requirement for number of road signs also increases, although the amount of road side space does not. One practical strategy to address this is to present multiple road signs on the same gantry (sign co-location). However, there is very little research on the safety implications of this practice.Method36 participants (mean age = 42.25 years, SD = 13.99, 18 females) completed three driving simulator scenarios, each scenario had a different sign co-location condition: no co-location, dual co-location and triple co-location. Each scenario presented similar information using direction signs, variable message signs and variable speed limit signs, under. Each drive included standard motorway driving (100 km/h speed zone) in free flow traffic and one emergency event where a lead vehicle suddenly braked. The scenario order was counterbalanced and the emergency event vehicle varied.ResultsOverall, there was no impact of co-locating signs on general driving performance. No significant difference was observed between conditions for reaction time and minimum headway in response to the emergency event. Participants were able to correctly choose their destination whether the signs were co-located or not.DiscussionFor the particular configuration of signs tested there is no evidence that co-location negatively impacts driving performance. However, there may be some implications for travel speed and the manner in which the emergency event is responded to. Future work should confirm the findings on real roads. These findings provided support for sign co-location as a practical and safe option for displaying multiple road signs in a confined area.     

Executive functions and processing speed in children with mild to borderline intellectual disabilities and externalizing behavior problems

Several studies suggest impaired executive functions (EFs) in children with externalizing behavior problems and average intelligence (e.g., IQ > 85). Even though children with mild to borderline intellectual disabilities (MBID) are at higher risk of developing externalizing behavior problems compared to children with average intelligence, it is not yet clear if impaired EFs are also associated with the occurrence of externalizing behavior problems in children with MBID. In the current study, we therefore assessed three EF components (inhibition, cognitive flexibility, and working memory) as well as processing speed in children with MBID and externalizing behavior problems (n = 71) versus children with MBID with no such problems (n = 70). This was accomplished using a well-established computerized test battery. Even after IQ was controlled for, the children with MBID and externalizing behavior problems showed more impaired working memory performance. Differences for inhibition performance and processing speed were also found but less consistent across the tasks used to measure these aspects of EF. Cognitive flexibility was not more impaired in children with both MBID and externalizing behavior problems relative to children with MBID only. Our findings highlight working memory as a potential target to enhance the treatment of children with MBID and externalizing behavior problems.     

Mental abilities and school achievement: A test of a mediation hypothesis

This study analyzes the interplay of four cognitive abilities - reasoning, divergent thinking, mental speed, and short-term memory - and their impact on academic achievement in school in a sample of adolescents in grades seven to 10 (N = 1135). Based on information processing approaches to intelligence, we tested a mediation hypothesis, which states that the complex cognitive abilities of reasoning and divergent thinking mediate the influence of the basic cognitive abilities of mental speed and short-term memory on achievement. We administered a comprehensive test battery and analyzed the data through structural equation modeling while controlling for the cluster structure of the data. Our findings support the notion that mental speed and short-term memory, as ability factors reflecting basic cognitive processes, exert an indirect influence on academic achievement by affecting reasoning and divergent thinking (total indirect effects: β = .22 and .24, respectively). Short-term memory also directly affects achievement (β = .22).     

The interrelationship between speeded and unspeeded divergent thinking and reasoning, and the role of mental speed

The relationship between intelligence and creativity is still subject to substantial debate in the research literature. In the present study, we focused on core dimensions of both constructs, that is divergent thinking and reasoning. We hypothesized their relationship to depend both on the speededness of test tasks and on the subject's mental speed, positing that with increasing speededness of the tasks, mental speed would have a stronger impact on task outcomes. We disentangled the effects of task speededness and mental speed experimentally, testing 261 participants (mean age 14.48 years) with 12 divergent thinking and 12 reasoning tasks, 6 of each under power conditions, 6 time-constrained. In addition, we assessed mental speed with 6 tasks. We analyzed the data through structural equation modeling. Results confirmed our expectations: test speededness contributed significantly to mental speed variance in divergent thinking task performance. Divergent thinking assessed under time constraints was fully explained by divergent thinking assessed under power conditions and by mental speed. Divergent thinking and reasoning showed no correlation when controlling for mental speed. Our findings suggest that the correlations between divergent thinking and reasoning are mainly the result of variance both constructs share with mental speed, and that timed versus untimed test-taking plays a minor role.     

The development of temporal coordination in children

The ability to learn temporal patterns in sequenced actions was investigated in elementary-school age children. Temporal learning depends upon a process of integrating timing patterns with action sequences. Children ages 6-13 and young adults performed a serial response time task in which a response and a timing sequence were presented repeatedly in a phase-matched manner, allowing for integrative learning. The degree of integrative learning was measured as the slowing in performance that resulted when phase-shifting the sequences. Learning was similar for the children and adults on average but increased with age for the children. Executive function measured by Wisconsin Card Sorting Test (WCST) performance as well as a measure of response speed also improved with age. Finally, WCST performance and response speed predicted temporal learning. Taken together, the results indicate that temporal learning continues to develop in pre-adolescents and that maturing executive function or processing speed may play an important role in acquiring temporal patterns in sequenced actions and the development of this ability.     

Finger forces in fastball baseball pitching

Forces imparted by the fingers onto a baseball are the final, critical aspects for pitching, however these forces have not been quantified previously as no biomechanical technology was available. In this study, an instrumented baseball was developed for direct measurement of ball reaction force by individual fingers and used to provide fundamental information on the forces during a fastball pitch. A tri-axial force transducer with a cable having an easily-detachable connector were installed in an official baseball. Data were collected from 11 pitchers who placed the fingertip of their index, middle, ring, or thumb on the transducer, and threw four-seam fastballs to a target cage from a flat mound. For the index and middle fingers, resultant ball reaction force exhibited a bimodal pattern with initial and second peaks at 38–39 ms and 6–7 ms before ball release, and their amplitudes were around 97 N each. The ring finger and thumb produced single-peak forces of approximately 50 and 83 N, respectively. Shear forces for the index and middle fingers formed distinct peak at 4–5 ms before release, and the peaks summed to 102 N; a kinetic source for backspin on the ball. An additional experiment with submaximal pitching effort showed a linear relationship of peak forces with ball velocity. The peak ball reaction force for fastballs exceeded 80% of maximum finger strength measured, suggesting that strengthening of the distal muscles is important both for enhancing performance and for avoiding injuries.     

智力落后儿童听觉注意的稳定性研究

本研究通过对智力落后儿童和正常儿童听觉注意稳定性的比较研究,探索智力落后儿童听觉注意稳定性的特点及影响因素。结果表明:4岁智龄组智力落后儿童听觉注意稳定性较弱,低于或等于同智龄组正常儿童水平。智力落后儿童慢速和快速情境下的注意稳定性高于中速。信噪比也影响注意的稳定性,信噪比越低,注意稳定性越差。频率因素对智力落后儿童的影响不显著。     

汉语儿童的语音加工技能与其单词朗读技能的关系研究

以121名小学五年级学生为被试,采用测验法,考察了汉语儿童的语音技工技能与其英文单词朗读技能的关系。结果表明:语音加工技能的三种成分均能够对英文单词朗读技能产生影响,其中,语音意识对单词朗读技能具有重要影响,快速命名能力和语音工作记忆也能够对单词朗读技能产生影响。     

一般流体智力的结构与老化机制--结构方程模型的比较

近年来一般流体智力的认知结构与老化机制已成为认知研究中的一个热点。本研究通过结构方程模型探讨了认知加工速度、工作记忆、注意能力与一般流体智力的联系,结果表明：加工速度、控制性注意是一般流体智力的主要认知成分,工作记忆并非一般流体智力的认知成分,两者之间足共变关系。加入年龄因子的结构方程模型也证实了加工速度和控制性注意是一般流体智力老化的重要中介因子。