How do bicyclists respond to vehicles with adaptive headlamp systems? A nighttime study in an immersive virtual environment.

INTRODUCTION: The risk of motor vehicle-bicyclist crashes and fatalities is greater during nighttime than daytime lighting conditions, even though there are fewer cyclists on roadways at night. Vehicle Adaptive Headlamp Systems (AHS) aim to increase the visibility of bicyclists for drivers by directing a spotlight to illuminate bicyclists on or near the roadway. AHS technology also serves to alert bicyclists to the approaching vehicle by illuminating the road beneath the rider and by projecting a warning icon on the roadway. METHOD: Here, we examined how bicyclists respond to different AHS designs using a large screen, immersive virtual environment. Participants bicycled along a virtual road during nighttime lighting conditions and were overtaken by vehicles with and without an AHS system. The experiment included five treatment conditions with five different AHS designs. In each design a box of white light was projected beneath the rider; in four of the designs an icon was also projected on the road that varied in color (white or red) and position (to the left of the rider at midline or to the left of the front wheel). Participants in the control condition experienced only non-AHS vehicles. RESULTS: We found that riders in all AHS treatment conditions moved significantly farther away from overtaking vehicles with AHS systems, whereas riders in the control condition did not significantly move away from overtaking vehicles without AHS systems. PRACTICAL APPLICATIONS: The experiment demonstrates that AHS has potential to increase bicycling safety by influencing riders to steer away from overtaking vehicles.

Longitudinal and Concurrent Effortful Control as Predictors of Risky Bicycling in Adolescence: Moderating Effects of Age and Gender.

OBJECTIVE: Collisions between bicycles and motor vehicles are one of the leading risk factors for injury and death in childhood and adolescence. We examined longitudinal and concurrent effortful control (EC) as predictors of risky bicycling behavior in early- to mid-adolescence, with age and gender as moderators. We also examined whether EC was associated with parent-reported real-world bicycling behavior and all lifetime unintentional injuries. METHODS: Parent-reported EC measures were collected when children (N = 85) were 4 years old and when they were either 10 years (N = 42) or 15 years (N = 43) old. We assessed risky bicycling behavior by asking the adolescents to bicycle across roads with high-density traffic in an immersive virtual environment. Parents also reported on children's real-world bicycling behavior and lifetime unintentional injuries at the time of the bicycling session. RESULTS: We found that both longitudinal and concurrent EC predicted adolescents' gap choices, though these effects were moderated by age and gender. Lower parent-reported early EC in younger and older girls predicted a greater willingness to take tight gaps (3.5 s). Lower parent-reported concurrent EC in older boys predicted a greater willingness to take gaps of any size. Children lower in early EC started bicycling earlier and were rated as less cautious bicyclists as adolescents. Adolescents lower in concurrent EC were also rated as less cautious bicyclists and had experienced more lifetime unintentional injuries requiring medical attention. CONCLUSION: Early measures of child temperament may help to identify at-risk populations who may benefit from parent-based interventions.

How children judge affordances when walking and bicycling across virtual roads: Does mode of locomotion matter?

This investigation examined whether the mode of locomotion matters in how 8-, 10-, 12-, and 14-year-old children (N = 91) judge dynamic affordances in a complex perception-action task with significant safety risks. The primarily European American children in the sample came from the area of Iowa City, Iowa and were balanced for gender. The same children crossed a single lane of continuous traffic on foot and on bike (order counterbalanced) in identical immersive virtual environments. We found that although 8-year-olds chose significantly larger gaps when crossing on bike than on foot, these gaps were not large enough to compensate for their delay in entering the gap and their slowness in crossing the road. As a result, they ended up with less time to spare when exiting the roadway on bike than on foot. In contrast, 14-year-olds exhibited no difference in their gap choices on bike than on foot, nor did they exhibit a difference in their timing of entry into the gap. However, they crossed the road much more quickly on bike, resulting in significantly more time to spare when crossing on bike than on foot. The 10- and 12-year-olds' performance fit neatly between that of the 8- and 14-year-olds. We conclude that as children gained better control over the bike with age, they were better able to match their gap decisions with their crossing movements such that bicycling afforded even safer road-crossing than walking for 14-year-olds. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Do Simulated Augmented Reality Overlays Influence Street-Crossing Decisions for Non-Mobility-Impaired Older and Younger Adult Pedestrians?

OBJECTIVE: This study used a virtual environment to examine how older and younger pedestrians responded to simulated augmented reality (AR) overlays that indicated the crossability of gaps in a continuous stream of traffic. BACKGROUND: Older adults represent a vulnerable group of pedestrians. AR has the potential to make the task of street-crossing safer and easier for older adults. METHOD: We used an immersive virtual environment to conduct a study with age group and condition as between-subjects factors. In the control condition, older and younger participants crossed a continuous stream of traffic without simulated AR overlays. In the AR condition, older and younger participants crossed with simulated AR overlays signaling whether gaps between vehicles were safe or unsafe to cross. Participants were subsequently interviewed about their experience. RESULTS: We found that participants were more selective in their crossing decisions and took safer gaps in the AR condition as compared to the control condition. Older adult participants also reported reduced mental and physical demand in the AR condition compared to the control condition. CONCLUSION: AR overlays that display the crossability of gaps between vehicles have the potential to make street-crossing safer and easier for older adults. Additional research is needed in more complex real-world scenarios to further examine how AR overlays impact pedestrian behavior. APPLICATION: With rapid advances in autonomous vehicle and vehicle-to-pedestrian communication technologies, it is critical to study how pedestrians can be better supported. Our research provides key insights for ways to improve pedestrian safety applications using emerging technologies like AR.

A comparison of daytime and nighttime pedestrian road-crossing behavior using an immersive virtual environment.

OBJECTIVE: Reduced visibility for both drivers and pedestrians is a key factor underlying the higher risk of vehicle-pedestrian collisions in dark conditions. This study investigated the extent to which pedestrians adjust for the higher risk of road crossing at night by comparing daytime and nighttime pedestrian road crossing using an immersive virtual environment. METHOD: Participants physically crossed a single lane of continuous traffic in an immersive pedestrian simulator. Participants were randomly assigned to either the daytime or the nighttime lighting condition. The primary measures were the size of the gap selected for crossing and the timing of crossing motions relative to the gap. RESULTS: The results showed that there were no significant differences in gap selection or movement timing in daytime vs. nighttime lighting conditions. However, there was a marginal increase in the time to spare after crossing the road when crossing in the dark, likely due to an accumulation of small differences in gap choices and movement timing. CONCLUSION: This study suggests that pedestrians do not adjust their road crossing to account for greater risk at night. As such, this study adds to our understanding of the potential risk factors for pedestrian injuries and fatalities in nighttime conditions.

How Do Child ADHD Symptoms and Oppositionality Impact Parent-Child Interactions When Crossing Virtual Roads?

OBJECTIVE: This study examined how parents and children interact when crossing virtual roads together. We examined (1) whether children's inattention/hyperactivity and oppositionality and children's failure to jointly perform the task interfered with parents' efforts to scaffold children's road-crossing skill and (2) whether experience with the joint road-crossing task impacted children's subsequent performance in a solo road-crossing task. METHODS: Fifty-five 8- to 10-year-old children with and without attention-deficit/hyperactivity disorder and their parents first jointly crossed a lane of traffic in an immersive pedestrian simulator. Children then completed the same road-crossing task alone. Parents completed questionnaires about children's symptoms of inattention/hyperactivity and oppositionality. RESULTS: Analyses of the joint road-crossing task showed that when parents and children crossed different gaps, parents suggested and opposed more gaps and were less likely to use a prospective gap communication strategy (i.e., communicating about a crossable gap prior to its arrival). Crossing different gaps was also associated with increased expressions of negative affect among parents and children and an increase in collisions among children. Children's level of parent-reported oppositionality also predicted an increase in child defiance and parental redirection of child behavior. Analyses of children's subsequent crossing performance indicated that parents' use of a prospective gap communication strategy during the joint road-crossing task predicted selection of larger gaps during the solo crossing task. CONCLUSIONS: Not crossing through the same gap and increased levels of child oppositionality interfered with the scaffolding process, potentially informing future parent-based intervention efforts for increasing children's road-crossing safety.

How do pedestrians respond to adaptive headlamp systems in vehicles? A road-crossing study in an immersive virtual environment.

Three-fourths of pedestrian fatalities in the U.S. occur in the dark (National Center for Statistics and Analysis, 2020). Adaptive Headlight Systems (AHS) offer the potential to address this problem by improving the visibility of pedestrians for drivers and alerting pedestrians to approaching vehicles. The goal of this study was to investigate how pedestrians respond to different types of AHS. We conducted a mixed factor experiment with 106 college-age adults using a large-screen pedestrian simulator. The task for participants was to cross a stream of continuous traffic without colliding with a vehicle. There were four AHS treatment conditions that differed in the color (white or red) and timing of an icon projected on the roadway in front the participant as an AHS vehicle approached. Participants in the treatment conditions encountered a mix of AHS and non-AHS vehicles. There was also a control condition in which participants encountered only non-AHS vehicles. We found that the color and the timing of the icon projected on the roadway influenced the size of the gaps crossed. Participants in the red icon with early onset condition chose the largest gaps for crossing. An unexpected outcome was that participants in the AHS treatment conditions chose larger gaps even when crossing in front of non-AHS vehicles, suggesting that experiences with AHS vehicles generalized to non-AHS vehicles. We conclude that AHS can have a significant, positive impact on pedestrian road-crossing safety.

Do Inattention/Hyperactivity and Motor Timing Predict Children's Virtual Road-Crossing Performance?

OBJECTIVE: The goal of this investigation was to examine how individual variation in inattention and hyperactivity is related to motor timing difficulties and whether children's performance on simple laboratory timing tasks is related to their performance on a virtual road-crossing task using a head-mounted virtual reality display system. METHODS: Participants were a community sample of 92 9- to 11-year-old children. Parents completed questionnaires assessing their child's inattention and hyperactivity. Children completed two simple motor timing tasks (duration discrimination and synchronization-continuation) and crossed roads with continuous traffic in a head-mounted VR system. RESULTS: Higher parent-reported inattention and hyperactivity predicted poorer performance in the duration discrimination and synchronization-continuation tasks, but not the virtual pedestrian road-crossing task. Children with higher tap onset asynchrony in the synchronization-continuation task had poorer timing of entry into the gap in the virtual pedestrian road-crossing task. CONCLUSIONS: The findings provide further evidence that timing deficits are associated with individual differences in inattention and hyperactivity and that timing difficulties may be a risk factor for functional difficulties in everyday life.

Let's Cross the Next One: Parental Scaffolding of Prospective Control Over Movement.

This investigation examined parental scaffolding of children's prospective control over decisions and actions during a joint perception-action task. Parents and their 6-, 8-, 10-, and 12-year-old children (N = 128) repeatedly crossed a virtual roadway together. Guidance and control shifted from the parent to the child with increases in child age. Parents more often chose the gap that was crossed and prospectively communicated the gap choice with younger than older children. Greater use of an anticipatory gap selection strategy by parents predicted more precise timing of entry into the gap by children. This work suggests that social interaction may serve as an important experiential mechanism for the development of prospective control over decisions and actions in the perception-action domain.

Visually Scaling Distance from Memory: Do Visible Midline Boundaries Make a Difference?

We examined how 4- to 5-year-old children and adults use perceptual structure (visible midline boundaries) to visually scale distance. Participants completed scaling and no scaling tasks using learning and test mats that were 16 and 64 inches. No boundaries were present in Experiment 1. Children and adults had more difficulty in the scaling than no scaling task when the test mat was 64 inches but not 16 inches. Experiment 2 was identical except visible midline boundaries were present. Again, participants had more difficulty in the scaling than no scaling task when the test mat was 64 inches, suggesting they used the test mat edges (not the midline boundary) as perceptual anchors when scaling from the learning to the test mat.

Do mother-child conversations about safety differ in middle- and low-income families?

BACKGROUND: Children from low-income families experience a disproportionate number of unintentional injuries compared to their middle-income peers. Parents are well positioned to teach children about avoiding injury, yet little is known about parent-child safety conversations in low-income families. This study examined to what extent mother-child safety conversations differ between low- and middle-income families. METHODS: Mothers and their 8- to 10-year-old children from low- and middle-income families discussed and rated the safety of photos showing another child engaged in potentially dangerous activities. RESULTS: Dyads disagreed over safety ratings on a third of trials, and both middle- and low-income mothers were highly successful in resolving disagreements in their favor. Middle-income mothers justified their ratings by referring to almost twice as many dangerous features than outcomes, whereas low-income mothers generated roughly equal numbers of dangerous features and outcomes. Middle-income children did not differ in their references to dangerous features and outcomes, but low-income children focused heavily on dangerous outcomes relative to dangerous features. CONCLUSIONS: Describing how middle- and low-income families discuss safety is a first step in understanding whether similarities and differences contribute to how middle- and low-income children evaluate and navigate potentially dangerous situations.

How Does Crossing Roads with Friends Impact Risk Taking in Young Adolescents and Adults?

OBJECTIVE: The goal of this investigation was to examine how crossing roads with a friend versus alone affects gap decisions and movement timing in young adolescents and adults. METHODS: Ninety-six 12-year-olds and adults physically crossed a single lane of continuous traffic in an immersive pedestrian simulator. Participants completed 30 crossings either with a friend or alone. Participants were instructed to cross the road without being hit by a car, but friend pairs were not instructed to cross together. RESULTS: Pairs of adolescent friends exhibited riskier road-crossing behavior than pairs of adult friends. For gaps crossed together, adult pairs were more discriminating in their gap choices than adult solo crossers, crossing fewer of the smaller gaps and more of the larger gaps. This pattern did not hold for 12-year-old pairs compared to 12-year-old solo crossers. To compensate for their less discriminating gap choices, pairs of 12-year-olds adjusted their movement timing by entering and crossing the road more quickly. For gaps crossed separately, both adult and 12-year-old first crossers chose smaller gaps than second crossers. Unlike adults, 12-year-old first crossers were significantly less discriminating in their gap choices than 12-year-old second crossers. CONCLUSIONS: Compared to adults, young adolescents took riskier gaps in traffic when crossing virtual roads with a friend than when crossing alone. Given that young adolescents often cross roads together in everyday life, peer influences may pose a significant risk to road safety in early adolescence.

Is scaling up harder than scaling down? How children and adults visually scale distance from memory.

In three experiments (N = 288), we examined how the direction of the scale translation impacts how 4- to 5-year-old children and adults visually scale distance from memory. Participants first watched an experimenter place an object on a learning mat and then attempted to place a replica object on a test mat that was either identical (no scaling task) or different in scale (scaling task). In Experiment 1, both children and adults had difficulty scaling up from 16 to 128 in. (1:8 scaling ratio) but not scaling down from 128 to 16 in. (8:1 scaling ratio), suggesting that scaling up was harder than scaling down. In Experiment 2, we reduced the scaling ratio from 1:8 to 1:2 and found that children and adults had no difficulty scaling up from 16 to 32 in. or scaling down from 32 to 16 in.. In Experiment 3, we kept the scale ratio the same (1:2) but increased the size of the test mat and found that participants had difficulty with both scaling up from 32 to 64 in. and scaling down from 128 to 64 in.. We conclude that scaling up is not harder than scaling down. Rather, visually scaling distance is more difficult when participants cannot view both edges of the test mat simultaneously while making the scale translation. Across all experiments, 4- to 5-year-olds were less accurate than adults in their placements overall, but they exhibited the same patterns of performance on the scaling and no scaling tasks, suggesting that visual scaling processes are age-independent. The General Discussion focuses on how visual scaling emerges from a complex interplay of cognitive processes and visual constraints.

Mother-child communication about relative proximity to a landmark: What role does prototypicality play?

This investigation examined how prototypicality affects mother-child communication about relative proximity. In the first two experiments, mothers of 2.5-, 3.0-, and 3.5-year-old children verbally disambiguated a target hiding container from an identical non-target hiding container when the two containers were placed at a smaller (more prototypical) or larger (less prototypical) distance from a landmark. Children then searched for the hidden object. When the absolute distance was smaller, mothers used more consistent frames of reference in their directions and even 2.5-year-olds largely followed those directions successfully. When the absolute distance was larger, mothers used multiple reference frames in their directions (a "kitchen sink" strategy) and children had more difficulty in following directions (especially 2.5-year-olds). A third experiment in which we controlled mothers' directions confirmed that the increased absolute distance, and not the mothers' direction-giving strategies, led to 2.5-year-olds' impaired search performance. These results indicate that young children's understanding of relative proximity develops from more prototypical cases (smaller distances) to less prototypical cases (larger distances) and that mothers' attempts to compensate for young children's difficulty with less prototypical cases did not improve their search performance.

Joint Action in a Virtual Environment: Crossing Roads with Risky vs. Safe Human and Agent Partners.

This paper examines how people jointly coordinate their decisions and actions with risky vs. safe human and agent road-crossing partners (Fig. 1 ). The task for participants was to physically cross a steady stream of traffic in a large-screen virtual environment without getting hit by a car. The computer-generated (CG) agent was programmed to be either safe (taking only large gaps) or risky (also taking small gaps). The human partners were classified as safe (taking more large gaps) or risky (also taking some small gaps) based on their average gap size selection. We found that participants in all four conditions preferred to cross with their partner. As a consequence, the riskiness of the partner (both human and agent) influenced the riskiness of participants' gap choices. We also found that participants tightly synchronized their movement with both human and agent partners. The largest differences in performance between those paired with agent vs. human partners occurred on trials when participants crossed different gaps than their partners. This study demonstrates the potential for studying how people interact with CG agents when performing whole-body joint actions using large-screen immersive virtual environments.

Timing Is Almost Everything: How Children Perceive and Act on Dynamic Affordances.

A key challenge for the developing perception-action system is learning how to move the self in relation to other moving objects. This often involves perceiving and acting on affordances or possibilities for action that depend on the relation between the characteristics of the individual and the properties of the environment (Gibson, 1979). This chapter overviews our program of research on perceiving and acting on dynamic affordances (i.e., possibilities for action that vary over time). Our goal is to bridge the divide between basic and applied research by using road crossing as a model system for studying how children's ability to perceive and act on dynamic affordances undergoes change with age and experience. The basic task is for participants to cross virtual roads with continuous traffic either on foot or on a bicycle. This work reveals that children's gap choices and crossing motions are less tightly linked than those of adults. Children often choose the same size gaps as adults but time their entry into those gaps less tightly than adults. As a result, children typically end up with less time to spare than adults when they clear the path of the vehicles. Improvement in gap selection and movement timing occurs gradually over development, indicating the perception-action system undergoes continuous change well into adolescence. As in other areas of development (e.g., face perception, word recognition), this kind of gradual developmental change appears critical for the fine-tuning of the system. The late development of these skills may explain also why adolescent pedestrians, cyclists, and drivers continue to be at risk for collisions when crossing roads. Further work aimed at better understanding the developmental mechanisms underlying these changes will inform the fields of both developmental science and injury prevention.

Harnessing Vehicle-to-Pedestrian (V2P) Communication Technology: Sending Traffic Warnings to Texting Pedestrians.

OBJECTIVE: We examined how sending mobile-device warnings to texting pedestrians when they initiate an unsafe road crossing influences their decisions and actions. BACKGROUND: Pedestrian texting has been identified as a key risk factor in pedestrian-vehicle collisions. Advances in sensing and communications technology offer the possibility of providing pedestrians with information about traffic conditions to assist them in safely crossing traffic-filled roadways. However, it is unclear how this information can be most effectively communicated to pedestrians. METHOD: We examined how texting and nontexting pedestrians crossed roads with continuous traffic in a large-screen, immersive pedestrian simulator using a between-subjects design with three conditions: texting, warning, and control. Texting participants in the warning condition received an alarm on their cell phone when they began to cross a dangerously small gap. RESULTS: The results demonstrate the detrimental influence of texting on pedestrians' gap selection, movement timing, and gaze behavior, and show the potential of warnings to improve decision making and safety. However, the results also reveal the limits of warning texting participants once they initiate a crossing and possible overreliance on technology that may lead to reduced situation awareness. CONCLUSION: Mobile devices and short-range communication technologies offer enormous potential to assist pedestrians, but further study is needed to better understand how to provide useful information in a timely manner. APPLICATION: The technology for communicating traffic information to pedestrians via mobile devices is on the horizon. Research on how such information influences all aspects of pedestrian behavior is critical to developing effective solutions.

Changes in perception-action tuning over long time scales: How children and adults perceive and act on dynamic affordances when crossing roads.

This investigation examined developmental change in how children perceive and act on dynamic affordances when crossing roads on foot. Six- to 14-year-olds and adults crossed roads with continuous cross-traffic in a large-screen, immersive pedestrian simulator. We observed change both in children's gap choices and in their ability to precisely synchronize their movement with the opening of a gap. Younger children were less discriminating than older children and adults, choosing fewer large gaps and more small gaps. Interestingly, 12-year-olds' gap choices were significantly more conservative than those of 6-, 8-, 10-, and 14-year-olds, and adults. Timing of entry behind the lead vehicle in the gap (a key measure of movement coordination) improved steadily with development, reaching adultlike levels by age 14. Coupled with their poorer timing of entry, 6-, 8-, and 10-year-olds' gap choices resulted in significantly less time to spare and more collisions than 14-year-olds and adults. Time to spare did not differ between 12-year-olds, 14-year-olds, and adults, indicating that 12-year-olds' more conservative gap choices compensated for their poorer timing of entry. The findings show that children's ability to perceive and act on dynamic affordances undergoes a prolonged period of development, and that older children appear to compensate for their poorer movement timing skills by adjusting their gap decisions to match their crossing actions. Implications for the development of perception-action tuning and road-crossing skills are discussed. (PsycINFO Database Record

Linking "what" and "where" information: How the strength of object categories influences children's memory for object locations.

We conducted three experiments to examine how the degree of category relatedness among objects in a group affects the magnitude of spatial bias in memory for their locations. Four age groups-7-, 9-, and 11-year-old children and adults-learned the locations of 20 objects marked by dots on a touchscreen monitor. After learning the object locations, participants attempted to place the objects without the aid of the dots. We compared spatial bias at test (i.e., placing objects in the same quadrant closer together than they really were) when objects within the same quadrant were strongly related versus unrelated (Experiment 1) or weakly related versus unrelated (Experiment 2). The 9-year-olds, 11-year-olds, and adults exhibited significant spatial bias when groups of objects were composed of either strongly or weakly related exemplars, but the 7-year-olds exhibited significant spatial bias only when the objects were strongly related. A third experiment revealed that the 7-year-olds exhibited only marginally significant spatial bias when objects within the same quadrant were weakly related and we cued them about the category labels beforehand. The General Discussion focuses on developmental changes in bottom-up associative processes and top-down strategic processes in memory for object locations.