Patricia R. DeLucia - US grants

This project is funded from the Research Experiences for Undergraduates (REU) Sites program in the SBE Directorate. As such, it has both scientific and societal benefits, and it integrates research and education. The REU Site at Texas Tech University advances research that aims to understand the cognitive, social, and physical capabilities and limitations of people and translates that knowledge to practical benefits for society. This area of psychological sciences, known as human factors, which is a subfield of applied experimental psychology, is vital in addressing societal challenges including those in aviation, health care, energy, transportation, and cyber-security, creating a large and increasing workforce need for human factors professionals. The REU Site will introduce undergraduates to an area with plentiful job opportunities and develop their research skills, making them attractive to graduate programs in various disciplines, and to industry employers seeking individuals who can apply research training to practical issues such as evaluating products and user interfaces. The REU Site supports diversity in social and behavioral sciences by recruiting under-represented groups to participate. Results of the research will advance the state of the art in the field and will have broad practical implications including traffic crashes, patient safety, education, human-robot interaction, substance use and misuse, health-based disparities, baggage screening, and occupational injuries.

The main goals of the REU Site are to engage undergraduates in behavioral research that has clear value in solving real-world problems, to develop research, teamwork, and communication skills applicable to any career in social and behavioral sciences, and to increase the number of undergraduates-- particularly those in underrepresented groups, who pursue graduate education and careers in human factors psychology. During each of three years, 8 undergraduates will work closely with faculty members at Texas Tech University on behavioral research with important applications such as driving, human-robot interaction; surgery; enhancement of student learning; applications of neuroscience to baggage screening; substance use and misuse; health-based disparities; and occupational injuries.

PROJECT SUMMARY Although individuals with complete vision loss can compensate by relying on audition, much less is known about whether such sensory substitution is used by individuals with residual vision, who represent a much larger portion of the visually impaired population. Few studies measured judgments of collision, which are essential for safe mobility, or the relative weights assigned to different sources of visual and auditory information, which is important for training and rehabilitation. We will address these gaps by measuring the relative contribution of visual and auditory information used by visually impaired individuals to make judgments of collision with obstacles in the environment. Results will advance a more individualized approach to rehabilitation and the development of assistive technologies, and will advance theories of collision perception. We will measure the abilities of 180 people to use visual and auditory information in judgments of collision, comparing those with central vision loss to age-matched as well as younger individuals with normal vision. We will create novel and compelling visual and acoustic computer simulations of approaching 3D vehicles, and compare judgments when auditory and visual information are presented concurrently to judgments when each is presented alone. By measuring judgments of when a collision would occur, and whether it is safe to cross a street in traffic, the proposed research will be the first to measure the degree to which auditory information is used during collision judgments when residual vision is available, and how much weight is assigned to different sources of visual and auditory information. Building on our collective expertise in collision perception, visual impairments, psychoacoustics, statistics, and 3D simulations, we will achieve three aims: 1) determine whether individuals who have partial vision loss compensate by relying on their hearing while making collision judgments, 2) determine whether individuals with partial vision loss achieve better collision judgments when they have auditory information in addition to their residual vision, compared to residual vision alone, and 3) measure how much weight individuals with partial vision loss assign to reliably accurate information (e.g., invariant of tau) compared to less reliable heuristics (e.g., depth cue of relative size) during collision judgments, and compare the weights to individuals with normal vision. Our pilot study showed that individuals with partial vision loss used their residual vision during collision judgments, placed more weight on visual cues than auditory cues, and placed more weight on less reliable heuristic cues. They also had smaller safety margins and more collisions during street-crossing judgments. By investigating multisensory processes in tasks essential for navigation by the visually impaired, we will help to fulfill the mission of the National Eye Institute to reduce the burden of eye disease. Results will help address the public health imperative to assist the more than 4 million middle-aged individuals with visual impairment or blindness to achieve mobility and independence, and will advance theories of collision perception.