Do infants have a sense of numerosity? A p‐curve analysis of infant numerosity discrimination studies

Research demonstrating that infants discriminate between small (e.g., 1 vs. 3 dots) and large numerosities (e.g., 8 vs. 16 dots) is central to theories concerning the origins of human numerical abilities. To date, there has been no quantitative meta‐analysis of the infant numerical competency data. Here, we quantitatively synthesize the evidential value of the available literature on infant numerosity discrimination using a meta‐analytic tool called p‐curve. In p‐curve the distribution of available p‐values is analyzed to determine whether the published literature examining particular hypotheses contains evidential value. p‐curves demonstrated evidential value for the hypotheses that infants can discriminate between both small and large unimodal and cross‐modal numerosities. However, the analyses also revealed that the published data on infants’ ability to discriminate between large numerosities is less robust and statistically powered than the data on their ability to discriminate small numerosities. We argue there is a need for adequately powered replication studies to enable stronger inferences in order to use infant data to ground theories concerning the ontogenesis of numerical cognition.     

The effect of the emotional state on driving performance in a simulated car-following task

Emotion is an important factor that influences driving behavior, but the mechanism is unclear. This research explored the effect of the emotional state on simulated driving behavior. Thirty-five licensed drivers participated in this study and completed a car-following task. The angry, happy and neutral states were manipulated during the task. The participants’ driving performance and risk perception were recorded under each emotional state. Trait anger and driving experience were also measured to explore the possible mediating effect. The results showed that the drivers in an angry or happy emotional state tended to maintain less time to collision and take a longer time to brake while following a lead vehicle than the drivers under the neutral condition, suggesting that drivers in emotional states are more dangerous those in neutral states. Moreover, the happy state rendered the drivers more dangerous, which manifested as a lower perceived accident risk than that among the drivers in the angry and neutral states. More specifically, experienced drivers in happy states performed worse with respect to vehicle lateral position control. Recommendations and implications for safety education and further research are discussed.     

Effects of training and display content on Level 2 driving automation interface usability

IntroductionLevel 2 driving automation features, such as adaptive cruise control (ACC) combined with lane centering, primarily communicate their operating statuses through the instrument cluster. It remains unclear how interface-specific training and display content influence the ability to understand Level 2 activity in production vehicles.MethodsEighty participants viewed videos recorded from the driver’s point of view in a variety of driving scenarios with Level 2 activity displayed in the instrument cluster of a 2017 Mercedes-Benz E-Class. Half viewed one of two instrument cluster layouts (simple or complex), and half received an orientation to the interface before the experiment. After each video, they were asked about the scenario they had just seen. We then examined what information in the displays participants used to identify Level 2 activity and the usability of the displays.ResultsTraining improved recognition accuracy of when lane centering was temporarily inactive and understanding of why it was inactive. Neither training nor display content affected the ability to recognize when ACC had adjusted the vehicle’s speed or detected a vehicle ahead, or when ACC initially did not detect a lead vehicle and understanding of why it had not detected it. Both factors influenced which sources of information participants used to determine Level 2 activity. Recognition accuracy of system activity improved when participants used valid sources of information. Training, but not display content, improved lane centering usability, but not ACC usability.DiscussionBasic training improves detection of notifications that potentially require further driver action, but not of those that display persistent status information. Training does not result in full understanding of all system notifications or functional limitations, which reinforces the need for intuitive, salient communication about system behavior and its limitations.     

Aging drivers and post delineated express lanes: Threading the needle at 70 miles per hour

Post-delineated express lanes represent a combination of driving complexities that are particularly difficult for older drivers to navigate. The narrow geometry and high speeds that are common to this treatment reflect a critical test for drivers whose depth perception, contrast sensitivity, and visual processing speed are reduced. The present study was designed to empirically examine the effects of age and color of express lane delineators on driver behavior. Three groups of participants (aged 18–39, 40–64, and 65 + years old) were required to complete a series of simulated driving scenarios consisting of combinations of single and dual lane configurations, with speed and lane position measured at the beginning and midpoint of each express lane. All drivers were pre-screened on various visual functioning abilities. Drivers in the 65 and older group show significant age-related declines in depth perception, contrast sensitivity, and phoria which were subsequently correlated with a wide range of driving measures including deceleration rate, brake time, jerk, speed, and lane position. Age related perceptual declines were statistically correlated with slower driving speed and wider lane deviations, including a statistically significant increase in the number of excursions beyond the typical 12-foot lane width. Based on these findings, the behavior of senior drivers was identified as a distinct design condition that should govern the design of high-speed, narrow geometric conditions. This age group requires wider lane widths, particularly at the beginning of single-lane post delimited sections, wider buffer areas around the post markers, and dual lane configurations wherever possible.     

The impact of cognitive functioning on driving performance of older persons in comparison to younger age groups: A systematic review

Older drivers are at a severely higher risk for motor vehicle crash involvement. Due to the global aging of the population, this increased crash risk has a significant impact on society, as well as on an older individual’s quality of life. For this reason, there is a need for understanding how normal age-related changes in cognition and underlying brain dynamics impact driving performance to identify the functional and neurophysiological biomarkers that could be used to design strategies to preserve or improve safe driving behavior in older persons. This review provides an overview of the literature on age-related changes in cognitive functioning and brain dynamics that impact driving simulator performance of healthy persons. A systematic literature search spanning the last ten years was conducted, resulting in 22 eligible studies. Results indicated that various aspects of cognition, most importantly executive function, complex attention, and dual tasking, were associated with driving performance, irrespective of age. However, there was a distinct age-related decline in cognitive and driving performance. Older persons had a more variable, less consistent driving simulator performance, such as more variable speed adaptation or less consistent lane keeping behavior. Only a limited number of studies evaluated the underlying brain dynamics in driving performance. Therefore, future studies should focus on implementing neuroimaging techniques to further unravel the neural correlates of driving performance.     

The impact of navigation system display size and environmental illumination on young driver mental workload

Driver distraction is a major cause of road crashes and has a great influence on road safety. In vehicles, one of the common distracting sources is navigation systems (NSs). The navigation system (NS) can distract the driver due to following directions and reading the provided information through its display. These tasks take the driver’s attention from the primary task of driving and may cause poor driving performance, increasing the risk of crashes. In this paper, the effect of the environment (i.e., urban areas and rural areas), the navigation system display (NSD) size, environmental illumination, and gender on young drivers between the ages of 18 and 29 years mental workload was investigated using a simulated driving experiment. To evaluate each driving condition, the NASA-TLX (NASA Task Load Index) workload assessment tool, and a distraction evaluation element, were introduced and used to assess the overall workload, the workload subscales and the distraction by the NSD. The assessment showed a higher perceived overall workload for urban areas and night driving as compared to a rural areas and daytime driving. Moreover, the results showed a greater perceived distraction by the NSD in urban areas compared to driving in rural areas. The subjects also felt distracted when using the small NS compared to using the large NS. The study concluded that urban areas driving, and night driving creates higher perceived workload than rural areas and daytime driving. Furthermore, small NSD leads to more perceived distraction than large NSD while driving. The NSD designers may utilize this research findings to optimize NSD designs to improve driving safety, performance and comfort. Moreover, this study contributes to our understanding of the effect of the NSD size on driving workload and distraction.     

Evaluating agents’ trustworthiness within virtual societies in case of no direct experience

A great deal of effort has been made to introduce trust models to assess trustworthiness within virtual societies. The great majority of them makes extensive use of direct experience as the main source of information, considering recommendation/reputation and inferential processes just later, as a secondary mechanism to refine trust assessment. In this kind of networks, unfortunately, direct experience might not always represent the best solution to assess trustworthiness. In fact, their highly dynamic structure promotes an increase of the average number of interconnections among agents. This in turn negatively affects the degree of knowledge the agents possess about each specific individual, i.e. direct experience. To date, however, it has not been said much about how to face these situations.It is fundamental to find an effective approach for trust assessment even in lack of direct experience, which is the central focus of this research. By the means of a multi-agent social simulation, we consider the situation in which an agent can just access indirect knowledge for trust assessment, namely recommendations of specific individuals or whole categories of individuals. Then, we compare the efficiency of these two approaches in order to identify when it is more convenient to rely on the first or on the second one. As expected, our results confirm that the dynamic nature of these networks strongly affects the role of categories. We modeled this feature introducing the “turnover” in the simulations, whereby the higher is the turnover the more convenient it is relying on categories. Besides this confirmatory result, our simulations highlight the higher degree of robustness of categories in the presence of unreliable recommenders. Such a result is even more significant if there is no available information about how reliable the recommenders are.The results we obtained are in accordance with the current literature and can be of important interest for the development of this sector.     

Relations entre réflexivité d’équipe,mémoire transactive et efficacité interventionnelle perçue chez les policiers-opérateurs du RAID

The objective of this study is to examine the influence of explicit (team reflexivity) and implicit (transactive memory) coordination processes on the perceived interventional effectiveness of specialized elite units (RAID) of the French national police. We test the hypothesis that transactive memory is a mediating process in the relationship between team reflexivity and perceived effectiveness. One hundred and three police-officers representing the seven French police special units replied to a questionnaire. The results show that perceived effectiveness is positively related to task reflexivity and transactive memory. The relationship between task reflexivity and perceived effectiveness is mediated by the integrated component of transactive memory (bootSE = 0.05, 95% BCa CI [0.004, 0.19]). The theoretical and practical implications are discussed with regard to the development of debriefing methods and teamwork training for the development of shared mental models.     

Investigating the effect of blood alcohol concentration on motorcyclist’s riding performance using an advanced motorcycle simulator

It is largely accepted that drink-driving significantly increases the likelihood that a driver may engage in risk-taking behavior and thus road crash. Although there have been a few studies examining the effect of blood alcohol concentration (BAC) on rider performance in developed countries, there has not been any research on the effect of BAC levels on motorcycle rider’s performance in developing countries. This study is attempted to evaluate the effect of low BAC levels (i.e., ≤0.05 g/dL or 0.05) on riding performance of motorcycle riders in Vietnam using an advanced motorcycle riding simulator. Thirty-four motorcycle riders aged 18–40 complete simulated rides on three BAC levels, namely 0.00, 0.02, and 0.05. Riding performance indicators are measured and compared at different BAC levels. These indicators include average speed, average lateral overtaking distance, brake reaction time, acceleration, deceleration, and frequency of lane change. At the level BAC = 0.02 or lower, the negative effects on the rider’s ability to control a motorcycle safely are statically insignificant. At the level BAC = 0.05, all the performances are impaired and the negative effects become statistically significant. In comparison of between novice participants and experienced participants at the same level of BAC, mean speed and acceleration rates of novice participants are significantly higher than the experienced participant. Based on the findings, the paper further discusses empirical relationships between reduced riding performances and road crash risk, and insights into drink-riding deterrence policy-making with regard to motorcycle riders.     

The power of nonverbal behavior: Penalty-takers’ body language influences impression formation and anticipation performance in goalkeepers in a simulated soccer penalty task

Previous research showed that penalty-takers’ body language affects the impressions goalkeepers form about them. Furthermore, it is often assumed that body language influences goalkeepers’ performance. However, as yet, there is no empirical evidence that indicates whether this latter effect exists. The present research was aimed at (1) replicating and offering more insight in the initial impression formation effects (Experiment 1-3) and (2) providing evidence that signals of dominance and submissiveness affect participants’ anticipation performance within a simulated soccer penalty task (Experiment 3). We report three experiments demonstrating that participants form more positive impressions and have less confidence in saving penalty kicks from dominant penalty-takers (or scoring against dominant goalkeepers, Experiment 1) than submissive penalty-takers (goalkeepers). However, we did not find evidence that participants’ automatic associations with dominant and submissive players underlie these findings (Experiment 2). Finally, we demonstrate that anticipation of kick direction is influenced by penalty-takers’ body language (Experiment 3). Participants performed worse in the simulated soccer penalty task against dominant than submissive penalty-takers. No mediation of impression formation was found.