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Thompson BJ, Cinelli ME. Collision avoidance behaviours while young adults avoid a virtual pedestrian approaching on a 45° angle under attentionally demanding conditions. Hum Mov Sci 2024; 95:103226. [PMID: 38728852 DOI: 10.1016/j.humov.2024.103226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 05/02/2024] [Accepted: 05/05/2024] [Indexed: 05/12/2024]
Abstract
Individuals rely on visual information to determine when to adapt their behaviours (i.e., by changing path and/or speed) to avoid an approaching object or person. After initiating an avoidance behaviour, individuals may control the space (i.e., minimum clearance distance) between themselves and another person or object. The current study aimed to determine the action strategies of young adults while avoiding a virtual pedestrian approaching along a 45° angle in an attentionally demanding task. Twenty-one young adults (22.9 ± 1.9 yrs., 11 males) were immersed in a virtual environment and were instructed to walk along a 7.5 m path towards a goal located along the midline. Two virtual pedestrians (VP) positioned 2.83 m to the left and right of the midline approached participants on a 45° angle. To manipulate the point at which the participants and the VP would intersect during different trials, the VP approached at one of three speeds: 0.8×, 1.0×, or 1.2× each participants' average walking speed. Participants were instructed to walk to a goal without colliding with the VP while performing the attention task; reporting whether a shape changed above the VPs' heads. Results revealed that young adults did not modulate their timing of avoidance to the approach characteristics of the VP, as they consistently avoided the collision 1.67 s after the VP began moving. However, young adults seem to control how they avoid an oncoming collision by maintaining a consistent safety margin after an avoidance behaviour was initiated.
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Affiliation(s)
- Brooke J Thompson
- Department of Kinesiology & Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Michael E Cinelli
- Department of Kinesiology & Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada.
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Cordes J, Schadschneider A, Nicolas A. Dimensionless numbers reveal distinct regimes in the structure and dynamics of pedestrian crowds. PNAS NEXUS 2024; 3:pgae120. [PMID: 38577258 PMCID: PMC10994203 DOI: 10.1093/pnasnexus/pgae120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 04/06/2024]
Abstract
In fluid mechanics, dimensionless numbers like the Reynolds number help classify flows. We argue that such a classification is also relevant for crowd flows by putting forward the dimensionless Intrusion and Avoidance numbers, which quantify the intrusions into the pedestrians' personal spaces and the imminency of the collisions that they face, respectively. Using an extensive dataset, we show that these numbers delineate regimes where distinct variables characterize the crowd's arrangement, namely, Euclidean distances at low Avoidance number and times-to-collision at low Intrusion number. On the basis of these findings, a perturbative expansion of the individual pedestrian dynamics is carried out around the noninteracting state, in quite general terms. Simulations confirm that this expansion performs well in its expected regime of applicability.
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Affiliation(s)
- Jakob Cordes
- Institute of Advanced Simulation, Forschungszentrum Jülich, 52428 Jülich, Germany
- Institut für Theoretische Physik, Universität zu Köln, 50937 Köln, Germany
| | | | - Alexandre Nicolas
- Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, F-69100 Villeurbanne, France
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Bourgaize SM, McFadyen BJ, Cinelli ME. Avoidance behaviours while circumventing to the left or right of someone with different shoulder widths and facing directions: How do side, width, or orientation matter? Hum Mov Sci 2023; 88:103071. [PMID: 36848722 DOI: 10.1016/j.humov.2023.103071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/07/2023] [Accepted: 02/21/2023] [Indexed: 02/27/2023]
Abstract
BACKGROUND Collision avoidance during locomotion is influenced by a variety of situational factors. When circumventing around an inanimate object, the amount of clearance is dependent on the side of avoidance. When avoiding other pedestrians, individuals most often choose to walk behind a moving pedestrian, and avoid people differently depending on their body size. However, side of avoidance has not been evaluated with human obstacles, nor facing direction of a stationary pedestrian, nor the size of a single pedestrian. Therefore, the aim of this study is to evaluate these knowledge gaps concurrently. RESEARCH QUESTION How do people avoid a collision to the left-side or right-side of a single stationary pedestrian (interferer) of varying shoulder width and orientation? METHODS Participants (n = 11) walked along a 10 m pathway towards a goal, while a stationary interferer stood 6.5 m from the start. The interferer faced one of three directions relative to the participant (orientation); forward, leftward, or rightward, with either their normal shoulder width or enlarged width created by wearing football shoulder pads. Participants were explicitly instructed as to which side of the interferer to avoid (forced-left vs forced-right). Each participant completed 32 randomized avoidance trials. Centre of Mass separation at the time of crossing was used to examine individual's avoidance behaviours. RESULTS Results revealed no effect of interferer width, but a significant side of avoidance effect, where the centre of mass separation between the participant and interferer at the time of crossing was smallest when participants avoided to their left. SIGNIFICANCE Findings suggest that changing the facing direction or artificially increasing the shoulder width of a stationary interferer will not affect one's avoidance behaviours. However, an asymmetry in side of avoidance is maintained similar to that observed in obstacle avoidance behaviours.
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Affiliation(s)
- Sheryl M Bourgaize
- Department of Kinesiology & Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada; Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Quebec City, QC, Canada
| | - Bradford J McFadyen
- Department of Rehabilitation, Faculty of Medicine, Université Laval, Quebec City, QC, Canada; Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Quebec City, QC, Canada
| | - Michael E Cinelli
- Department of Kinesiology & Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada.
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Saeedpour-Parizi MR, Hassan SE, Azad A, Baute KJ, Baniasadi T, Shea JB. Target position and avoidance margin effects on path planning in obstacle avoidance. Sci Rep 2021; 11:15285. [PMID: 34315936 PMCID: PMC8316463 DOI: 10.1038/s41598-021-94638-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 07/12/2021] [Indexed: 02/07/2023] Open
Abstract
This study examined how people choose their path to a target, and the visual information they use for path planning. Participants avoided stepping outside an avoidance margin between a stationary obstacle and the edge of a walkway as they walked to a bookcase and picked up a target from different locations on a shelf. We provided an integrated explanation for path selection by combining avoidance margin, deviation angle, and distance to the obstacle. We found that the combination of right and left avoidance margins accounted for 26%, deviation angle accounted for 39%, and distance to the obstacle accounted for 35% of the variability in decisions about the direction taken to circumvent an obstacle on the way to a target. Gaze analysis findings showed that participants directed their gaze to minimize the uncertainty involved in successful task performance and that gaze sequence changed with obstacle location. In some cases, participants chose to circumvent the obstacle on a side for which the gaze time was shorter, and the path was longer than for the opposite side. Our results of a path selection judgment test showed that the threshold for participants abandoning their preferred side for circumventing the obstacle was a target location of 15 cm to the left of the bookcase shelf center.
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Affiliation(s)
- Mohammad R. Saeedpour-Parizi
- grid.411377.70000 0001 0790 959XDepartment of Kinesiology, School of Public Health, Indiana University Bloomington, 1025 E 7th Street, Bloomington, IN 47405 USA ,grid.411377.70000 0001 0790 959XDepartment of Intelligent Systems Engineering, Luddy School of Informatics, Computing, and Engineering, Indiana University Bloomington, Bloomington, IN USA
| | - Shirin E. Hassan
- grid.411377.70000 0001 0790 959XSchool of Optometry, Indiana University Bloomington, Bloomington, IN USA
| | - Ariful Azad
- grid.411377.70000 0001 0790 959XDepartment of Intelligent Systems Engineering, Luddy School of Informatics, Computing, and Engineering, Indiana University Bloomington, Bloomington, IN USA
| | | | - Tayebeh Baniasadi
- grid.411377.70000 0001 0790 959XDepartment of Kinesiology, School of Public Health, Indiana University Bloomington, 1025 E 7th Street, Bloomington, IN 47405 USA
| | - John B. Shea
- grid.411377.70000 0001 0790 959XDepartment of Kinesiology, School of Public Health, Indiana University Bloomington, 1025 E 7th Street, Bloomington, IN 47405 USA
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Gaze behavior during pedestrian interactions in a community environment: a real-world perspective. Exp Brain Res 2021; 239:2317-2330. [PMID: 34091697 DOI: 10.1007/s00221-021-06145-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/27/2021] [Indexed: 10/21/2022]
Abstract
Locomotor adaptations, as required for community walking, rely heavily on the sense of vision. Little is known, however, about gaze behavior during pedestrian interactions while ambulating in the community. Our objective was to characterize gaze behavior while walking in a community environment and interacting with pedestrians of different locations and directions. Twelve healthy young individuals were assessed as they walked in a shopping mall from a pre-set location to a goal located 20 m ahead. Eye movements were recorded with a binocular eye-tracker and temporal distance factors were assessed using wearable sensors from a full-body motion capture system. Participants exhibited more numerous and longer gaze episodes on pedestrians (GEP) that were walking in the same direction as themselves vs. those that were in the opposite direction. The relative durations of GEPs, however, showed no significant differences between pedestrians walking in the same vs. opposite direction. Longer durations of GEPs were also observed for centrally located pedestrians compared to those located on either side, but this was the case only for pedestrians that were walking in the same direction as participants. In addition, pedestrians in the centre, and even more so those on the right, were fixated at farther distances compared to those on the left. Results indicate that healthy young individuals modulate their gaze behavior as a function of the location and direction of pedestrians when ambulating in a community environment. The observed modulation is interpreted as being caused by an interplay between collision risk, pedestrian visibility, presence of leaders and social conventions (right-sided circulation). Present results also establish baseline measures for the quantification of defective visuomotor strategies in individuals with mobility disorders.
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Keshner EA, Lamontagne A. The Untapped Potential of Virtual Reality in Rehabilitation of Balance and Gait in Neurological Disorders. FRONTIERS IN VIRTUAL REALITY 2021; 2:641650. [PMID: 33860281 PMCID: PMC8046008 DOI: 10.3389/frvir.2021.641650] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Dynamic systems theory transformed our understanding of motor control by recognizing the continual interaction between the organism and the environment. Movement could no longer be visualized simply as a response to a pattern of stimuli or as a demonstration of prior intent; movement is context dependent and is continuously reshaped by the ongoing dynamics of the world around us. Virtual reality is one methodological variable that allows us to control and manipulate that environmental context. A large body of literature exists to support the impact of visual flow, visual conditions, and visual perception on the planning and execution of movement. In rehabilitative practice, however, this technology has been employed mostly as a tool for motivation and enjoyment of physical exercise. The opportunity to modulate motor behavior through the parameters of the virtual world is often ignored in practice. In this article we present the results of experiments from our laboratories and from others demonstrating that presenting particular characteristics of the virtual world through different sensory modalities will modify balance and locomotor behavior. We will discuss how movement in the virtual world opens a window into the motor planning processes and informs us about the relative weighting of visual and somatosensory signals. Finally, we discuss how these findings should influence future treatment design.
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Affiliation(s)
- Emily A. Keshner
- Department of Health and Rehabilitation Sciences, Temple University, Philadelphia, PA, United States
- Correspondence: Emily A. Keshner,
| | - Anouk Lamontagne
- School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada
- Virtual Reality and Mobility Laboratory, CISSS Laval—Jewish Rehabilitation Hospital Site of the Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Laval, QC, Canada
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Limb movements of another pedestrian affect crossing distance but not path planning during virtual over ground circumvention. Neurosci Lett 2020; 736:135278. [PMID: 32721429 DOI: 10.1016/j.neulet.2020.135278] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 07/17/2020] [Accepted: 07/23/2020] [Indexed: 11/23/2022]
Abstract
Circumventing another pedestrian is a frequent daily activity. The literature has provided a better understanding about anticipatory locomotor adjustments based on global (whole body) movement, but how local limb movements of another pedestrian affect one's circumvention is not well known. The purpose of this study was to understand how local limb movements of another pedestrian affect the planning and execution to circumvent them. Ten healthy young adults (24.5 ± 3.0 years) were immersed in a virtual environment representing a shopping mall. Participants walked to a shop located directly in front of them while circumventing a virtual agent which, when present, approached from straight ahead with one of four different locomotor patterns: 1-Normal locomotor movements; 2- No arm movements; 3- No leg movements; 4- No arm and leg movements (gliding to them). Circumvention trajectory, minimum clearance and coordination of head and trunk rotations along with center of mass lateral displacement were examined. Nonparametric Analysis of Longitudinal Data was used to compare variables across the different conditions. Minimum clearance was smaller for normal locomotor movements compared to all other conditions, but coordination of body movements and onset of circumvention trajectory deviations remained unchanged. These results suggest that global body movement is sufficient to plan circumvention trajectories in a predictable avoidance task, but clearance safety margins are influenced by the local limb movements of another pedestrian.
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Bourgaize SM, McFadyen BJ, Cinelli ME. Collision avoidance behaviours when circumventing people of different sizes in various positions and locations. J Mot Behav 2020; 53:166-175. [PMID: 32188359 DOI: 10.1080/00222895.2020.1742083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The current study examined whether young adults' avoidance behaviours differed when circumventing a larger versus smaller interferer. It was expected that avoidance behaviours (repulsion) would be affected by the interferer's size (i.e., greater repulsion for larger body size). Participants (n = 20) walked along an 8 m pathway towards a goal while avoiding either a larger or smaller sized male interferer who stood stationary facing forward, backward, left, or right and were located 2, 4, or 6 m from the participants' starting position. Results revealed that there was an effect of interferer body size (personal-characteristics) and orientation (situational-characteristics) on M-L clearance between the interferer and participant at the time of crossing, suggesting that repulsion magnitudes are scaled to an interferer's closest body surface.
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Affiliation(s)
- Sheryl M Bourgaize
- Department of Kinesiology & Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Bradford J McFadyen
- Department of Rehabilitation, Faculty of Medicine, Université Laval, Québec City, QC, Canada.,Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Québec City, QC, Canada
| | - Michael E Cinelli
- Department of Kinesiology & Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada
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