Dennis R. Proffitt - US grants

space perception; motion perception; cognition; neural information processing; visual perception; stimulus /response; memory; attention; visual stimulus; imagination; thinking; mathematical ability; videotape /videodisc; human subject;

The PIs propose to investigate the causes of highway accidents. The PIs will develop fault trees based on the databases of state and national organizations. From these data the PIs will determine causal relationships among the vehicle features, driver behavior, and accident occurrence. Finally, guidelines will be generated for vehicle design modifications based upon the driver errors identified as most frequently as being a cause of accidents. The PIs will join with the General Motors Research Laboratories on this Private Sector Research Initiative.

This research is part of multi-stage program seeking to develop new methods in risk analysis building on multiobjective trade-off analysis of vehicle-safety interventions for evaluating changes in future vehicle design. In Phase I of this effort, fault-tree models for accident causation and consequence were developed that use historical accident databases to analyze the potential effectiveness of vehicle safety features. Phase II integrated the `100 Crashes` scenarios (a data-driven catalog of severe accident types), accident statistics from Michigan, and expert assessment of safety technologies to demonstrate a trade-off analysis of the benefits and costs of 15 prospective vehicle safety features. This funding supports Phase III, and adapts the fault trees for event-occurrence rates that are based on travel exposure, applies them to crash scenarios of automated urban interstates, and assesses the performance benefits of vehicle-safety technologies in order to reduce the losses of lives and property on automated highway systems. This research is funded under the Joint NSF/Private Sector Initiative with the continued strong collaboration of senior scientists from General Motors.

EIA-0130800
David Luebke
University of Virginia

This project will construct a state-of-art immersive display at the University of Virginia. Specifically, the investigators will build a wide field-of-view tiled display, using passive stereo projection, 6-DOF head tracking, and spatialized audio to create an extremely immersive 3-D audio-visual display environment. This display will benefit and enable three separate research projects in the Computer Science and Psychology departments: gaze-directed rendering, perceptually driven physical simulation and animation, and cognitive design of human-computer interfaces. Tiling multiple projectors will create a display spanning a very wide field of view; two projectors per tile will enable passive stereo display with lightweight polarizing glasses. An audio system, a head tracker, and realistic scanned 3-D environments will enable immersive and convincing virtual worlds. The wide field-of-view will provide an ideal testbed for gaze-directed rendering, which accelerates interactive rendering by exploiting reduced visual acuity (e.g., for peripheral or fast-moving objects), and for perceptually driven physical simulation, which selectively degrades simulation accuracy according to perceptual metrics. The human-computer interface project investigates immersive ambient context to improve human memory. The stereo head-tracked capabilities of the new display will literally add a new dimension to the investigation, enabling full 3-D environmental cues.

Unlike social judgments, perceptual judgments are anchored in concrete reality and are thought to be independent of social context. However, recent investigations suggest that even perceptions of physical space can be influenced by the social and emotional context. The proposed research explores such social and affective factors in perception. In contrast to traditional theories, ecological approaches suggest that perception may depend on contextual factors not previously considered. For example, some research shows that hills seem steeper to a person wearing a heavy backpack (Bhalla & Proffitt, 1999). Contextual factors influence perception because they are relevant to actions: A hill is harder to climb for an encumbered person, and thus, appears as steeper. In contrast to physical properties, such as the weight of a heavy backpack, not much is known about properties that are more "psychological," such as the social and affective nature of an interactive environment. Social and affective factors, such as being in a group or being in a good mood, are known to influence social judgments such as ratings of life satisfaction. The proposed research will explore whether perceptual judgments are similarly influenced by "the power of the situation."

The goal of the proposed research is to determine to what extent perception is shaped by social and affective factors. Several studies will examine the influence of a number of different factors on estimates of distances to objects and slants of hills, such as whether another person is present, or what affective values judgment objects have. Building on this beginning, an additional outcome of the proposed research is the development of perceptual measures that reveal people's affective responses to various stimuli. That is, if people's feelings influence how they perceive distances to attitude objects, then it should also be the case that one can infer their attitudes from their perceived distances. By examining these hypotheses, we expect to get a glimpse of how social factors affect basic processes previously assumed to be insulated from such influences.

The Broader Impact of the project includes educational experiences for the persons involved in the research, such as for the undergraduate and graduate students working on the project, as well as for research participants who will receive detailed information about the research as part of their debriefing after participation. This research promotes interdisciplinary as well as international collaboration. Findings from the project are expect to be broadly disseminated by the public media, because previous research by the investigators involved in the project has attracted considerable attention in the popular press. Findings involving participants' gender, racial and ethnic background will be informative in investigating the extent to which cultural differences in spatial behavior are associated with differences in spatial perception.

Severe motor disabilities significantly impact the quality of life for millions of people worldwide. The most profound motor disability, so-called locked-in syndrome, describes people who are completely paralyzed and unable to speak - they are intelligent and alert, but unable to communicate even their most basic needs. Several technologies, based on detecting minute electrical changes in brain signals, have been assessed for whether they can provide a channel of communication for people with locked-in syndrome; although the results from these studies are encouraging, the interfaces are slow, highly error prone, and often require weeks or months of training before control is achieved. Functional Near-Infrared (fNIR) imaging is a new and promising brain-imaging technology that measures small changes in blood volume and oxygenation in the brain. The technology has been explored for augmented cognition and for diagnosis, but has not been investigated for its control potential. Initial studies in able-bodied and locked-in subjects suggest that fNIR control is more accurate, easier to activate, and does not require any training. The overall goal of this research is to fully characterize and test fNIR imaging for control application. To this end, the PIs will first conduct a comprehensive study to determine optimal fNIR activation methods (e.g., determination of mental tasks that can be easily performed and that result in detectable brain activations). The product of this study will be a screening protocol that can be used to determine the most controllable brain area and device configuration for an individual user. The PIs will also work to improve fNIR imaging methods, by conducting offline and online studies to determine optimal sensitivity, cortical depth, filters, and signal processing algorithms for fNIR control. The product of this study will be an fNIR imaging device that is as accurate, sensitive, and robust as possible, as well as a set of heuristics for optimally configuring the device for a particular user. Finally, the PIs will demonstrate fNIR control in real-world applications by determining optimal mappings of fNIR signals to traditional assistive technology control interfaces such as scanning or logical interfaces, cursor movement, and direct selection. The results from all of these studies will be validated by combining and incorporating the findings into a comprehensive test of the fNIR system, by implementing a system for in-home use to control devices such as light switches, a television, and an MP3 player, which will be tested with five locked-in subjects.

Broader Impacts: For people with severe motor disabilities, the implications of researching and improving access to assistive technologies are profound. This research will make a significant contribution to the area of brain-computer interfaces by introducing a new, unexplored brain imaging method for control. It will also add to the body of knowledge for assistive technology and human-computer interfaces, by establishing protocols and mappings between an fNIR device and control interfaces. There are many people with less profound motor impairments (e.g., palsy), who might also be helped by an fNIR input device. Further research in fNIR control could lead to control of prosthetics that could restore movement in paralyzed limbs. Additionally, interface strategies for low-bandwidth, high error rate contexts may have significant application in other domains such as mobile and wearable computing systems and hands-free device operation.

DESCRIPTION (provided by applicant): The aim of the proposed research is to investigate emotional influences on the perception of spatial layout, and more specifically, how fear influences the perception of heights. In a representative study, participants would stand on a high balcony and would provide indices of the apparent distance to the ground. This research is based on recent work, which showed that the perception of spatial layout was influenced by the physiological state of the observer (Proffitt, Bhalla, Gossweiler, &Midgett, 1995;Bhalla &Proffitt, 1999;Proffitt, Stefanucci, Banton, &Epstein, 2003). For instance, observers who wore a heavy backpack saw slants as steeper and distances as farther than those who did not wear a backpack. Recent work has shown that fear also influences the perception of relevant spatial layout. Steep hills, which would be impossible to descend on foot, appear steeper when viewed from the top than from the bottom. Steep hills also appear steeper when viewed from the top while standing on a skateboard as opposed to standing on a box of equivalent height. Establishing a relationship between emotion and perception would not only extend our understanding of perception, but would also provide insights into the nature and treatment of fears and phobias. Traditionally, the focus has been on relatively higher-level cognitive processing, such as biases in attention and memory. In a sense, we seek to show that fearful individuals literally see the world through a "distorted lens." To test this hypothesis, we will conduct three sets of studies. First, we will determine the parameters for normative height perception. We will employ various methodologies to obtain assessments of perceived height in both the real world and virtual reality. Assessments of fear and postural sway will also be collected and correlated with the apparent height measures. The norms and measures established will be used in the subsequent studies. Next, we will conduct a series of studies to determine if increases and reductions in state-level fear produce differences in height estimation. We will also test alternative hypotheses by introducing arousal and alternative mood manipulations. We predict that perceived height will increase when participants are frightened, but not when they are aroused for different reasons or in different moods. These experiments will allow us to better understand the underlying mechanisms by which fear affects perception of height. Finally, we will assess whether phobias influence estimates of height. Specifically, we will investigate whether individuals with a specific phobia toward heights (termed acrophobia) show larger changes in height estimation relative to other-fear and control groups. We will also test whether fear reduction (after habituation of fear through exposures) attenuates the overestimation of heights expected in persons with acrophobia.

Severe motor disabilities, including locked-in syndrome and paralysis, impact the quality of life for millions of people worldwide. The PIs' prior work in brain-computer interfaces based on functional near-infrared (fNIR) imaging has shown great promise for restoring communication and environmental control to people with such disabilities. Currently, typical control interfaces for these systems are simple discrete selection paradigms, which have proven to be effective but limited in information throughput rates. Innovative control interfaces based on continuous control paradigms, which dynamically map brain signal levels to control signals, have not been adequately studied for fNIR imaging. Depending upon the extent to which brain signals can be effectively mapped to continuous control, adding this feature to existing discrete control could significantly increase the range of tasks that can be performed by users of an fNIR-based direct brain interface (e.g., positional selection or 2-D drawing). In this work, the PIs will explore innovative direct brain-computer interfaces for continuous control and use them to develop applications for creative expression. For people with severe motor disabilities, creative expression can provide an emotional outlet as well as mental exercise to improve quality of life. The tasks inherent in creating visual art, such as drawing, coloring, and texturing, cannot be accomplished with discrete controls. Therefore, visual art provides an ideal experimental platform to study fNIR-based continuous control interfaces. It also provides an engaging and motivating platform for training that will improve users' abilities to control a direct brain interface. To these ends, the PIs will study non-traditional control interfaces for continuous and discrete selection such as wheels, dials, and gauges, to determine to what extent fNIR signals can be mapped to continuous control. The PIs will explore continuous methods for selection and control of art media such as brushes, colors, textures, and shapes, and investigate to what extent continuous brain signals can be translated into visual art gestures (drawing, shading, coloring). The advice of a professional, internationally-known artist who has ALS will guide the user requirements of the control interfaces. Quantitative and qualitative user performance data will be collected, and will among other things be used to compare learning effects with a visual art paradigm against traditional, discrete selection exercises to determine if training time and performance can be improved. Project outcomes will add to the body of knowledge for assistive technology and human-computer interfaces.

Broader Impacts: Methods for translating cortical oxygenation signals into continuous control signals for user interfaces will have mainstream applications for assistive technologies by essentially "smoothing" noisy input signals. Such developments could be applied for use by those with reduced motor coordination, including the elderly, young children, and those with motor diseases such as Parkinson's disease. Mainstream users may benefit from a hands-free interface, and neural control could provide added dimensions to the creative process.