Browsing by Author "DeLucia, Patricia R"

Now showing 1 - 5 of 5
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    A Systematic Review and Meta-Analysis of Takeover Performance during Conditionally Automated Driving
    (2020-06-17) Weaver, Bradley William; DeLucia, Patricia R
    Background: For conditionally automated driving, the driver is responsible for taking over vehicle control when the system reaches a limit. The objective of this paper was to synthesize what factors affect this takeover. Method: Out of 8,446 articles identified by a systematic literature search, 48 articles were included in the meta-analysis. Coded independent variables were time budget, non-driving related task engagement and resource demands, and information support. Coded dependent variables were takeover timing and quality measures. Results: Engaging in non-driving related tasks results in degraded takeover performance, particularly if it has overlapping resource demands with the driving task. Weak evidence suggests takeover performance is impaired with shorter time budgets. There is a lack of evidence that information support affects takeover performance. Conclusion: Future research and application should focus on providing the driver more time to take over or minimize the degradation of situation awareness while automation is active.
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    Direct Learning for Time-to-Collision Judgments of Approaching Objects: The Role of Fractal 1/f Noise in Exploration
    (2020-04-14) Braly, Adam M; DeLucia, Patricia R; Kortum, Philip; Lane, David M; Sano, Akane
    The purpose of this dissertation was to determine whether direct learning can improve time-to-collision (TTC) judgments of approaching objects. Accurate information for judgments of TTC is available in the optic array, but research has shown that observers do not always use this accurate information. Even though this information exists in the optic array, observers may not be attuned to use such information. According to direct learning theory, observers must be able to flexibly combine exploration and feedback to calibrate their judgments. This could explain why prior studies found that observers relied on other less reliably accurate sources of information. Research has also shown that fractal fluctuations in exploration involve fluctuations at all time scales, which ostensibly allows perceptual systems the flexibility to detect information. Therefore, fractal fluctuations in exploration may reflect coordination among detection, calibration, and attunement of information for perception or action. This dissertation tested whether judgments of TTC were significantly better when participants were permitted to make exploratory movements with feedback compared to when they were restricted and not given feedback. In a virtual environment, participants viewed scenes of an object that approached them. After a designated time, the object disappeared and participants judged when the object would have reached them, had it continued to move. Exploration and feedback were factorially crossed to create four between-subjects conditions of Exploration- Feedback, Exploration- No Feedback, No Exploration- Feedback, and No Exploration- No Feedback. Results showed that participants in the Exploration- Feedback learned to used more accurate information for their judgments and this improvement was retained in the absence of further feedback. Participants in the No Exploration- Feedback appeared to learn how to use accurate information, but in the absence of further feedback their performance degraded, suggesting a strategy based on feedback rather than learning. Results of fractal analyses revealed that exploratory movements were fractal, and that trail-by-trial fluctuations in the fractal scaling exponent predicted perceptual error. The findings have implications for theories of TTC perception and practical implications are discussed.
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    Effect of Cyclists' Communication Cues on Drivers' Perceptions of Intent
    (2023-10-23) Petersen, Christine Marie; DeLucia, Patricia R
    Background: There has been an increase in the number of fatal crashes between cyclists and drivers over the last decade. One potential cause of collisions between these road users is a driver’s inability to correctly predict a cyclist’s intentions. The current research aimed to determine what cues drivers used to make correct judgments of intent and assessed where drivers looked when asked to make judgments of intent. Methods: Drivers were shown video clips of a cyclist performing different combinations of cues (position on the road, head movement, arm signals). They were asked to report what they believed the cyclist intended to do (i.e., turn left, turn right, stop, or go straight). The scene ended before the cyclist performed the intended action. After the driver made their decision, they were asked to describe to the experimenter what cues they used to make their decision. Results: The results revealed that the likelihood of a driver correctly predicting the cyclist’s intentions depended only on the arm signal presented and not on head movement or position on the road. The straight arm signals were the only signals correctly predicted by all drivers. Less than a quarter of the drivers correctly predicted the bent right turn arm signal. Results of eye movement measures also showed that drivers directed their attention to the back of the cyclist and then redirected their attention to where a signal was being presented. Conclusion: Overall, drivers could correctly predict a cyclist’s intentions when straight arm signals were presented. Transportation laws should be rewritten to remove the bent right turn arm signal to improve cyclists' safety.
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    Effect of Motorcycle Lighting Configurations on Drivers’ Perceptions of Closing
    (2021-06-25) Weaver, Bradley William; DeLucia, Patricia R
    Background: Motorcyclists account for a disproportionate number of roadway fatalities, especially at night. One major cause of this is drivers misjudging the approach of an oncoming motorcycle. The current research aimed to better understand how drivers perceive an approaching set of headlights and determined whether alternative motorcycle headlight configurations improved drivers’ perceptual judgments of closing for an oncoming motorcycle. Method: The first experiment examined whether drivers are more sensitive to horizontal or vertical optical expansion and whether drivers can integrate these two dimensions to achieve a lower looming threshold. A second experiment built on these results to inform the design of alternative motorcycle headlight configurations and tested whether these alternative headlight configurations were better than other motorcycle headlight configurations and a car’s headlights. For both experiments, participants were instructed to press a button to indicate when they first perceived an oncoming vehicle to be closing under nighttime driving conditions. Results: The first experiment showed drivers perceived closing at about the same looming threshold for horizontally-oriented and vertically-oriented motorcycle headlight configurations, and drivers perceived closing for a combined horizontal-vertical headlight configuration at a significantly lower looming threshold compared to the horizontal configuration but not compared to the vertical configuration. The second experiment showed the alternative motorcycle headlight configurations that accentuated the full extent of a motorcycle’s height or both its height and width resulted in drivers perceiving closing sooner than other motorcycle headlight configurations but not as soon as a car. Conclusion: Orientation does not affect driver’s looming threshold for closing, and drivers are not able to integrate optical expansion from multiple dimensions in a way that achieves a lower looming threshold. However, drivers do perceive closing sooner for larger headlight configurations compared to smaller headlight configurations unless the headlight configurations are relatively small.
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    The Relationship between Eye Movements and Audiovisual Time-to-Contact Estimates in Young and Old Adults
    (2024-12-04) Cloutier, Melissa; DeLucia, Patricia R
    Introduction: This dissertation investigated how saccadic eye movements, aging, and central vision loss affect time-to-contact (TTC) estimates in a dynamic, traffic-related environment. The goal was to explore the role of eye movement behaviors and sensory integration across different adult populations, including younger adults, older adults, and individuals with age-related macular degeneration (AMD), in both visual and audiovisual contexts. Method: Two experiments were conducted. In Experiment 1, participants completed TTC tasks in visual-only and audiovisual conditions; half of them were instructed not to make saccadic eye movements. Experiment 2 examined TTC estimates and eye movement behaviors in younger and older adults, as well as individuals with AMD and older adults with normal vision, in both visual and audiovisual modalities. Results: In Experiment 1, individuals who made saccadic eye movements had significantly higher TTC estimates in the visual-only modality than in the audiovisual condition. However, individuals who did not make saccadic eye movements had similar TTC estimates in the visual-only and audiovisual modalities. In Experiment 2, older adults exhibited shorter fixation durations compared to younger adults, and their longer fixations led to greater underestimations of TTC, which resulted in safer judgments. Individuals with AMD had less stable eye movements than older adults with normal vision but they made more accurate TTC estimates in the audiovisual condition compared to the visual-only condition, indicating a reliance on auditory cues to compensate for visual deficits. Conclusion: These findings reveal that eye movements affect TTC judgments when information is presented visually but not when both auditory and visual stimuli are presented. Aging and central vision loss alter the relationship between eye movements and TTC judgments. Older adults with normal vision and adults with central vision loss underestimated TTC when they made longer fixations, suggesting that the relationship between TTC estiamtes and eye movements changes as a result of age and visual abilities.