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.

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.

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.

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.

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.

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.

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.

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.

Risky bicycling behavior among youth with and without attention-deficit hyperactivity disorder.

BACKGROUND: Injury risk from car-bicycle collisions is particularly high among youth with attention-deficit hyperactivity disorder (ADHD). Here, we capitalized on advances in virtual environment technology to safely and systematically examine road-crossing behavior among child cyclists with and without ADHD. METHODS: Sixty-three youth (26 with ADHD, 37 non-ADHD controls) ages 10-14 years crossed 12 intersections with continuous cross-traffic while riding a high-fidelity bicycling simulator. Traffic density (i.e., temporal gaps between vehicles) was manipulated to examine the impact of varying traffic density on behavioral indices of road crossing, including gap selection, timing of entry into the roadway, time to spare when exiting the roadway, and close calls with oncoming cars. In addition, parents filled out questionnaires assessing their child's ADHD symptomatology, temperamental characteristics, bicycling experience, and injury history. RESULTS: ADHD youth largely chose the same size gaps as non-ADHD youth, although ADHD youth were more likely to select smaller gap sizes following exposure to high-density traffic. In addition, youth with ADHD demonstrated poorer movement timing when entering the intersection, resulting in less time to spare when exiting the roadway. Hyperactivity-impulsivity symptoms were specifically associated with selection of smaller gaps, whereas timing deficits were specifically associated with inattention and inhibitory control. CONCLUSION: Findings highlight two related yet potentially dissociable mechanisms that may influence injury risk among youth with ADHD and provide a foundation for development of injury prevention strategies.