Learning your way around town: how virtual taxicab drivers learn to use both layout and landmark information

By having subjects drive a virtual taxicab through a computer-rendered town, we examined how landmark and layout information interact during spatial navigation. Subject-drivers searched for passengers, and then attempted to take the most efficient route to the requested destinations (one of several target stores). Experiment 1 demonstrated that subjects rapidly learn to find direct paths from random pickup locations to target stores. Experiment 2 varied the degree to which landmark and layout cues were preserved across two successively learned towns. When spatial layout was preserved, transfer was low if only target stores were altered, and high if both target stores and surrounding buildings were altered, even though in the latter case all local views were changed. This suggests that subjects can rapidly acquire a survey representation based on the spatial layout of the town and independent of local views, but that subjects will rely on local views when present, and are harmed when associations between previously learned landmarks are disrupted. We propose that spatial navigation reflects a hierarchical system in which either layout or landmark information is sufficient for orienting and wayfinding; however, when these types of cues conflict, landmarks are preferentially used.     

Influence of body-centered information on the transfer of spatial learning from a virtual to a real environment

This study investigated the effects of body-centred information on the transfer of spatial learning using a wayfinding task and tasks that specifically probe the route and survey strategies of navigation. The subject learned a route in either a real or a virtual environment (VE; 3D scale model of a Bordeaux neighbourhood) and then reproduced it in the real environment. The involvement of body-based information was manipulated across the spatial learning conditions in the VE: participants learned with full body-based information (treadmill with rotation), with the translational component only (treadmill without rotation) or without body-based information (joystick). In the wayfinding task, the results showed a significant effect of the learning environment with the best scores obtained in the real and treadmill with rotation conditions. There was no significant difference between these two conditions, but the real condition was significantly different from the treadmill without rotation and joystick conditions. Also, the visual flow was sufficient to successfully perform the two egocentric tasks used as well as a direction estimation task (a survey task), in so far as there is no significant difference between the joystick and the treadmill conditions. By contrast, the distance estimates were improved by the treadmill condition including the translational component (but not the rotational component). Finally, our results show that treadmill with rotation promotes the transfer of spatial learning from a virtual to a real environment (compared to joystick and treadmill without rotation). Moreover, body-centred informations are more involved in allocentric (distance estimates) than egocentric navigational strategies.     

Effects of route familiarity on drivers’ psychological conditions: Based on driving behaviour and driving environment

Route familiarity affects a driver’s mental state and indirectly affects traffic safety; however, this important factor is easily overlooked. Previous research on route familiarity has only analysed psychological states in terms of unfamiliarity and familiarity, the influence of driving behaviour and driving environment on psychological states has been ignored. As a result, the mechanisms through which the route familiarity influence driver psychological states, and vice versa, are unclear. This study proposes a quantitative framework for studying driver psychological condition and route familiarity using experimental data from a real driving task and driving environment data. The experimental data included 1022 observations obtained by 23 participants over 7 consecutive trials on 6 unfamiliar experimental routes with large differences in scenarios; environmental data were automatically extracted after segmenting a driving video through the Dilated Residual NetWorks model. The results reveal that (1) the relationship between the driver’s psychological condition and route familiarity is not monotonic and is different for straight and turning sections; (2) the driver’s psychological condition is influenced by the visual scene elements and the type of road section, and the results of the multivariate regression analysis quantified the variability of the influence; and (3) unlike a majority of findings on distracted driving, our study suggest that the driver’s attention to the external environment in the urban distracted driving state will gradually approach a ‘distraction threshold’, and the time and size of the ‘distraction threshold’ are influenced by the driver. This study can further the development of urban traffic safety research and help urban designers plan and improve urban landscapes to ensure drivers maintain stable mental states when they drive.     

Performance and presence with head-movement produced motion parallax in simulated driving

Driving simulator studies can reveal relevant and valid aspects of driving behavior, but underestimation of distance and speed can negatively affect the driver’s performance, such as in performance of overtaking. One possible explanation for the underestimation of distance and speed is that two-dimensional projection of the visual scene disrupts the monocular-based illusory depth because of conflicting binocular and monocular information of depth. A possible solution might involve the strengthening of the monocular information so that the binocular information becomes less potent. In the present study, we used an advanced high-fidelity driving simulator to investigate whether adding the visual depth information of motion parallax from head movement affects sense of presence, judgment of distance and speed, and performance measures coupled with overtaking. The simulations included two types of driving scenario in which one was urban and the other was rural. The main results show no effect of this head-movement produced motion parallax on sense of presence, head movement, time to collision, distance judgment, or speed judgment. However, the results show an effect on lateral positioning. When initiating the overtaking maneuver there is a lateral positioning farther away from the road center as effect of the motion parallax in both types of scenario, which can be interpreted as indicating use of naturally occurring information that change behavior at overtaking. Nevertheless, only showing tendencies of effects, absent is any clear additional impact of this motion parallax in the simulated driving.     

目标预知对路径整合的影响

本研究采用头盔式虚拟现实与返回起点或路标的路径完成任务, 通过指导语来调控被试对于返回位置的预知, 检验目标预知对人类路径整合的影响。实验结果表明, 对于返回起点这一目标的预知可以使被试有效地忽略由于路标出现或路标数量增加而导致的干扰, 而对于返回路标这一目标的预知程度越高, 可以促使被试做出更准确的反应。这样的结果体现了目标预知作为一种非感知觉因素对于人类路径整合的影响, 也体现了人类路径整合的策略性和灵活性。     

Conflicts of interest: The implications of roadside advertising for driver attention

There is growing concern that roadside advertising presents a real risk to driving safety, with conservative estimates putting external distractors responsible for up to 10% of all road traffic accidents. In this report, we present a simulator study quantifying the effects of billboards on driver attention, mental workload and performance in Urban, Motorway and Rural environments. The results demonstrate that roadside advertising has clear adverse effects on lateral control and driver attention, in terms of mental workload. Whilst the methodological limitations of the study are acknowledged, the overriding conclusion is that prudence should be exercised when authorising or placing roadside advertising. The findings are discussed with respect to governmental policy and guidelines.     

Revised reinforcement sensitivity theory: The impact of FFFS and stress on driving

This study investigated the effect of a fear-based personality trait, as conceptualized in Gray’s revised reinforcement sensitivity theory (RST) by the strength of the Fight/Flight/Freeze system (FFFS), on young people’s driving simulator performance under induced psychosocial stress. Seventy-one young drivers completed the Jackson-5 questionnaire of RST traits, followed by a psychosocial stress or relaxation induction procedure (random allocation to groups) and then a city driving simulator task. Some support was found for the hypothesis that higher FFFS sensitivity would result in poorer driving performance under stress, in terms of significantly poorer hazard responses, possibly due to an increased attentional focus on the aversive cues inherent in the stress induction leaving reduced attentional capacity for the driving task. These results suggest that stress may lead to riskier driving behaviour in individuals with fearful RST personality styles.     

Spider monkey ranging patterns in Mexican subtropical forest: do travel routes reflect planning?

Although it is well known that frugivorous spider monkeys (Ateles geoffroyi yucatanensis) occupy large home ranges, travelling long distances to reach highly productive resources, little is known of how they move between feeding sites. A 11 month study of spider monkey ranging patterns was carried out at the Otochma’ax Yetel Kooh reserve, Yucatán, Mexico. We followed single individuals for as long as possible each day and recorded the routes travelled with the help of a GPS (Global Positioning System) device; the 11 independently moving individuals of a group were targeted as focal subjects. Travel paths were composed of highly linear segments, each typically ending at a place where some resource was exploited. Linearity of segments did not differ between individuals, and most of the highly linear paths that led to food resources were much longer than the estimate visibility in the woodland canopy. Monkeys do not generally continue in the same ranging direction after exploiting a resource: travel paths are likely to deviate at the site of resource exploitation rather than between such sites. However, during the harshest months of the year consecutive route segments were more likely to retain the same direction of overall movement. Together, these findings suggest that while moving between feeding sites, spider monkeys use spatial memory to guide travel, and even plan more than one resource site in advance. This contribution is part of the special issue “A Socioecological Perspective on Primate Cognition” (Cunningham and Janson 2007).     

What is a Person? And Why it Matters in Religious Ethics

Here I respond to four critics of my book, What Is a Person?, seeking to find areas of common ground and crucial disagreement. Most importantly, I explore the question of whether all human knowledge is conceptually mediated, acknowledging that, no, indeed, there are likely forms of experiential knowledge that are purely and directly acquired without conceptual mediation.