Michael A. Webster - US grants

The proposed research is designed to examine the properties of contrast adaptation in the human visual system. Contrast (pattern-selective) adaptation profoundly influences perception by adjusting sensitivity according to the pattern of stimulation to which observers are exposed. The goal of the present proposal is to investigate the changes in color perception that result from adaptation to chromatic stimuli, through psychophysical measurements on a computer-controlled color display. Specific aims include measurement and analyses of (1) how contrast adaptation influences color appearance and color constancy (the perceived color of the same surface viewed under different illuminants); (2) how these adaptation effects interact with the properties of light adaptation (to the mean luminance and chromaticity in the stimulus); and (3) how color and form perception are influenced by adaptation to spatial stimuli. Understanding these adaptation phenomena is important for understanding normal visual function, and would thus be important for understanding the implications and consequences of visual dysfunction.

The proposed research is designed to examine processes of contrast (pattern-selective) adaptation in the human visual system, and how this adaptation regulates the perception of color and form in stimuli characteristic of the natural visual environment. Sensitivity to color and form can be strongly influenced by adaptation to the chromatic and spatial properties of natural scenes, yet the implications of these sensitivity changes for visual coding remain poorly understood. The goal of the present proposal is to examine the functional consequences of adaptation, by exploring how adaptation alters the relative salience of color or form within scenes. Measurements and analyses of natural scene statistics will be combined with psychophysical studies that probe both perceptual and performance measures of visual salience and how it varies with natural variations in the observer's state of adaptation. The specific aims of the project include measurements to characterize I) how the perceptual salience of color depends on the color properties characteristic of natural backgrounds, and how color salience is affected by adaptation to the background; 2) how adaptation to the characteristic spatial structure of images influences the salience of structure at different spatial scales in images; and 3) how adaptation to natural spatial configurations alters the relative salience of different image configurations. The latter experiments focus on human face perception and how the salience of natural facial configurations may be biased by the large changes that adaptation induces in the appearance of faces. The results of these studies would be important for understanding how pattern-selective adaptation modulates perception and performance, and thus for understanding the possible roles that the adaptation plays in visual coding. Assessing these effects in natural viewing conditions is important for revealing how adaptation influences the natural operating characteristics of the human visual system, and thus for understanding the implications and consequences of visual dysfunction.

Project summary Vision is a highly dynamic system that continuously adapts to changes in the stimulus properties of the environment or the physiological properties of the observer. How these adaptation processes adjust to the sensitivity limits of the observer is important for understanding normal visual function and the consequences of visual deficits or disease. The proposed research examines basic mechanisms of adaptation and plasticity by examining how color vision adjusts to losses in color sensitivity as a result of inherited color deficiencies. Color- deficient observers with anomalous trichromacy have weaker sensitivity to reddish-greenish colors because of alterations in the genes coding the medium and longwave photopigments. However, there is emerging evidence that the perceptual experience of color in anomalous trichromats is stronger than their sensitivity losses predict, potentially because the neural mechanisms encoding color amplify and thus compensate for the reduced color signals available from their receptors. Color deficiencies provide an ideal model for exploring these compensatory mechanisms, by comparing observers who differ because of well-defined and highly stable properties of the initial receptors, for which they have had a lifetime to adapt. The proposed studies are designed to assess the extent and mechanisms of these compensatory adjustments and how they are manifest in and impact different aspects of color perception. The first aim will compare color perception and contrast coding in normal and color-deficient observers across a battery of tasks designed to isolate different levels and properties of color vision. The second aim will complement these behavioral assessments with direct measures of cortical neural activity in normal and color-anomalous observers using functional magnetic resonance imaging, electroencephalography, and adaptive optics to probe neural responses to color. The results of these studies will serve to better characterize the neural and perceptual consequences of color deficiencies, and more generally will characterize basic processes underlying human vision and how it adapts in response to visual losses or their corrections.

The Adminstrative Core ofthe Integrative Neuroscience COBRE will be directed by Michael Webster (Professor of Psychology). This core will oversee training and development for the project leaders and the mentoring plan. It will organize the meetings ofthe Internal Faculty Development Committee (composed of project mentors and core directors) and the Internal Advisory Committee (senior faculty consultants to the director), and will facilitate the communication between all COBRE personnel. It will also organize the meetings with the External Advisory Committee. The Administrative Core will prepare progress reports and provide these for the EAC and NCRR, and serve as a liaison between the COBRE and the univiersity, other UNR COBRE's, and the Nevada INBRE program. The Administrative Core will also maintain the website for the COBRE. The core will be based in space in the Psychology Building (Mack Social Science), on the same floor as the proposed MRI and patient database cores, and on the same floor as the offices and labs of the project director and two of the project leaders (with new space for all cores provided by the university as committed in their letters of support). The core will administer travel funds for training and for attending the annual meetings of the NCRR, and will support the seminar series to bring leading investigators to UNR to discuss their work. Finally, this core will be responsible for the ongoing evaluation and assessment of the COBRE.

PROJECT SUMMARY/ABSTRACT Overall This proposal is continue the development of a Center of Biomedical Research Excellence (COBRE) in Integrative Neuroscience at the University of Nevada, Reno (UNR). Nationally, advances in the neurosciences are proceeding on many fronts and addressing fundamental questions in both basic and clinical science. The COBRE at UNR was established to synergize and elevate the capacity for neuroscience research at UNR and the state of Nevada, by 1) cross-fertilizing research units that had already developed teams of focused expertise in cognitive or cellular neuroscience or bioengineering; and 2) providing the modern infrastructure required to mount impactful research programs in the field. Phase I has supported seven projects and five pilot projects spanning both basic and clinical research. Mentored project leaders have achieved very high productivity in both peer-reviewed publications and NIH and NSF funding. Phase I also developed research cores with high impact and use, including establishing the first fMRI facility in the region. The resources provided through the cores have expanded far beyond the original aims, and have been mounted in ways that are highly cost-effective and sustainable. Phase II will further expand and solidify these successes, supporting an initial team of 5 projects that will continue to build UNR?s strength in cellular and cognitive neuroscience while also targeting strategic growth in computational neuroscience. The project leaders will be mentored by a strong team of successful researchers who will bring perspectives and expertise drawn from many disciplines, with a framework chosen to foster real interdisciplinary collaborations. Research cores for Neuroimaging and Molecular Imaging will be expanded to provide an array of critical tools and training that will both strengthen and open new research opportunities for COBRE projects and the broader neuroscience community. A new core will also be developed to support applications of virtual and augmented reality for sensory and cognitive neuroscience, an area where we have again identified high potential impact and need. Finally, the COBRE will continue to drive the rapid growth of other neuroscience initiatives at UNR, by becoming the research arm of a new Institute of Neuroscience that will be established with university support at the beginning of Phase II. This will allow the research aims of the center to connect with and leverage the recently initiated Graduate Program in Integrative Neuroscience, and begin the transition to a permanent and self-sustaining research center.

PROJECT SUMMARY/ABSTRACT The Vision Sciences Society is a nonprofit membership organization of nearly 2000 scientists interested in the functional aspects of vision. VSS was founded in 2001 with the purpose of bringing together scientists from a broad range of disciplines including visual psychophysics, visual neuroscience, computational vision and visual cognition. The scientific content of the meetings reflects the breadth of topics and interconnected ideas and approaches in modern vision science, from visual coding to perception, recognition and the visual control of action, as well as recent developments in cognitive psychology, computer vision and neuroimaging. Since its founding, VSS has provided a forum and framework for communicating advances in vision science, and VSS has become a flagship conference for the field. The interdisciplinary nature of VSS is reflected in the deliberately diverse membership of the Board of Directors and Abstract Review Committee. Many of the faculty from institutions in the United States who attend VSS are principal investigators of National Eye Institute grants; hence, the research objectives of the programs of the National Institutes of Health and of the National Eye Institute are well-represented in the program planning and individual presentations. Over 60% of participants are predoctoral and postdoctoral trainees. Of these 55% are US citizens. VSS provides multiple career development opportunities: (1) the platform and poster presentations provide a forum for trainees to showcase their work and receive feedback, (2) career-development workshops cover topics such as ?Getting that Faculty Job?, ?Reviewing and Responding to Reviews?, ?The Public Face of your Science?, ?Careers in Industry and Government?, ?Faculty Careers at Primarily Undergraduate Institutions?, and include panel discussions with journal editors, NIH and NSF grant officers, and academic and industry representatives, (3) a ?Meet the Professors? event in which trainees meet in small groups with members of the VSS Board and other professors for free-wheeling, open-ended discussions, and (4) a partnership with ARVO to host a symposium series that exposes VSS attendees to advances in clinical research from ARVO members and ARVO attendees to advances in basic research from VSS members. VSS also provides many formal events and informal opportunities for networking with peers and senior colleagues in a comfortable and engaging setting. The large contingent of early-stage investigators at VSS is a sign of the strong health of the field and the opportunity VSS provides for advancing the field. Our goal is to facilitate access and participation for this next generation of vision scientists. VSS previously received a one-year R13 award to support the 2019 meeting by providing travel awards for postdoctoral trainees and early-career faculty. Based on the success and positive impact of this initial support, the purpose of this 5-year proposal is to provide 48 travel awards per year for early-career investigators to attend the 2020-2024 meetings, with the focus on attracting and supporting a diverse pool of undergraduate and graduate students, postdoctoral trainees, and pre-tenure faculty who demonstrate potential for future success as vision researchers and whose research findings will be presented at the meeting. Funds are also requested to offset the registration costs for undergraduate attendees in order to significantly expand access and participation at the conference for students first encountering the field of vision science.

Project Summary/Abstract Digital breast tomosynthesis (DBT) has emerged as a viable imaging modality for breast cancer screening. But despite its improvements over standard mammography, the breast imaging community is well aware of its limitations. Roughly 40 million women in the United States have a screening mammogram each year, and the combination of a high-volume exam and less than ideal performance have made screening mammography an active area of research for many years. Prior studies have shown that reading breast screening images in batches improves performance, in terms of lower overall recall rates without significant change in the cancer detection rate. But no mechanism for this improvement has been demonstrated. A recently published clinical trial in the UK with over 1 million screening mammograms read by 360 practicing clinicians finds that screening performance actually improves as a reader progresses through a batch of mammograms. We hypothesize that, rather than vigilance, the operational mechanism affecting performance in batch reading is adaptation, which is consistent with improved performance over the course of a batch. We propose to characterize sequential reading effects in DBT images, to see if there is evidence to support our hypothesis that readers visually adapt to the statistical structure of the images as they read them. A few studies have shown adaptation effects in digital mammograms, but there have been no studies to date evaluating sequential effects in DBT. If adaptation is functioning in batch reading of DBT images, then there are a variety of was to take advantage of it to improve screening performance. We propose a thorough evaluation of sequential effects in DBT images that includes basic visual assessments of adaptation, statistical analysis of retrospective clinical data, and prospective analysis of performance in clinical reader studies. These will be analyzed to determine if image readers are consistent with the adaptation hypothesis, improved performance with depth in a batch, and modeled to see if there are additional factors that influence adaptation. Our project consists of three specific aims that cover these topics. Aim 1 implements a battery of visual assessments that define and characterize visual adaptation to DBT images. Aim 2 proposes mining clinical DBT reading data at the University of Pittsburgh Medical Center to evaluate retrospective performance detecting cancer (true-positive rates) and recalling patients (false-positive rates). This data will be modeled with factors that include adaptive sequential effects. Aim 3 will evaluate screening performance in DBT images in ?laboratory? studies using clinical readers and cases that evaluate the effects of different batch length and the ordering of cases within a batch.

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

The University of Nevada-Reno aims to add a 10 node A100 Graphics Processing Unit (GPU)-based cluster to their pre-existing Central Processing Unit (CPU) cluster with the expressed aim of creating a more central facility to expand access across campus. The projects aims to meet present and anticipated Artificial Intelligence (AI)/Machine Learning (ML) workloads in various research group on campus. Twenty-first century science and engineering is being transformed by the increasing scales of research computing and data. Despite the increase in the demand for large-scale and data-centric computational resources, it is still a struggle to provide domain scientists with the necessary tools and support at campus-levels. Specifically, decentralized computing practices not only bottleneck research because of lack of scale and support, but also decouple computing from higher performance and deeper storage and networks. Accordingly, shifts in institutional cyberinfrastructure strategies are required, with the following guiding priorities: (1) improving user friendly access; (2) removing perceived barriers in the use of scalable infrastructure; and (3) building multidisciplinary communities for next-generation workflows.

The University of Nevada, Reno (UNR) will add a new A100 GPU-based cluster to its pre-existing CPU cluster to introduce a new set of paradigms for interdisciplinary computing infrastructure and expand access across campus. Each A100 OnDemand node is equipped with 24-core CPUs and A100 GPU accelerators, interconnected with Infiniband switches to provide effective access to science drivers at UNR and externally through Open Science Grid. This cluster has potential to meet UNR’s present and anticipated workloads of various research groups on campus by addressing three main requirements: (1) capability to support dozens to hundreds of concurrent interactive session users through the Multi Instance GPU (MIG) capabilities of the A100 GPUs; (2) support for modern tensor core architectures to facilitate machine learning workflows; and (3) colocation on the UNR research perimeter network and adjacency to high performance storage. This project is a significant step for the under-resourced institution in computing resources and capability. The planned integration with Open Science Grid (OSG) will open a door to on-demand access to millions of hours of heterogeneous compute cycles for researchers on campus.

This project is funded through the collaborative efforts of the Office of Advanced Cyberinfrastructure (OAC) and the Established Program to Stimulate Competitive Research (EPSCoR).

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.