Marcus Thiebaux

Toward the holodeck: integrating graphics, sound, character and story

We describe an initial prototype of a holodeck- like environment that we have created for the Mission Rehearsal Exercise Project. The goal of the project is to create an experience learning system where the participants are immersed in an environment where they can encounter the sights, sounds, and circumstances of real-world scenarios. Virtual humans act as characters and coaches in an interactive story with pedagogical goals.

Sex differences in mental rotation and spatial rotation in a virtual environment

The visuospatial ability referred to as mental rotation has been shown to produce one of the largest and most consistent sex differences, in favor of males, in the cognitive literature. The current study utilizes both a paper-and-pencil version of the mental rotations test (MRT) and a virtual environment for investigating rotational ability among 44 adult subjects. Results replicate sex differences traditionally seen on paper-and-pencil measures, while no sex effects were observed in the virtual environment. These findings are discussed in terms of task demands and motor involvement. Sex differences were also seen in the patterns of correlations between rotation tasks and other neuropsychological measures. Current results suggest men may rely more on left hemisphere processing than women when engaged in rotational tasks.

A high-throughput x-ray microtomography system at the Advanced Photon Source

~Received 14 November 2000; accepted for publication 23 January 2001!A third-generation synchrotron radiation source provides enough brilliance to acquire completetomographic data sets at 100 nm or better resolution in a few minutes. To take advantage of suchhigh-brilliance sources at the Advanced Photon Source, we have constructed a pipelined dataacquisition and reconstruction system that combines a fast detector system, high-speed datanetworks, and massively parallel computers to rapidly acquire the projection data and perform thereconstruction and rendering calculations. With the current setup, a data set can be obtained andreconstructed in tens of minutes. A specialized visualization computer makes renderedthree-dimensional~3D! images available to the beamline users minutes after the data acquisition iscompleted. This system is capable of examining a large number of samples at sub-mm 3D resolutionor studying the full 3D structure of a dynamically evolving sample on a 10 min temporal scale. Inthe near future, we expect to increase the spatial resolution to below 100 nm by using zone-platex-ray focusing optics and to improve the time resolution by the use of a broadband x-raymonochromator and a faster detector system.

Virtual environment applications in clinical neuropsychology

Virtual environment (VE) technology is increasingly being recognized as a useful medium for the study, assessment, and rehabilitation of cognitive processes and functional abilities. The capacity of VE technology to create dynamic three-dimensional (3D) stimulus environments, within which all behavioral responding can be recorded, offers clinical assessment and rehabilitation options that are not available using traditional neuropsychological methods. This work has the potential to advance the scientific study of normal cognitive and behavioral processes and to improve our capacity to understand, measure, and treat the impairments typically found in clinical populations with central nervous system (CNS) dysfunction. The paper provides a rationale for the application of VE technology in the areas of neuropsychological assessment and cognitive rehabilitation, presents a tabled summary of the VE literature targeting cognitive/functional processes in clinical CNS populations and briefly describes two of our VE applications targeting attention and visuospatial processing.

Distance visualization: data exploration on the grid

Our increased ability to model and measure a wide variety of phenomena has left us awash in data. In the immediate future, the authors anticipate collecting data at the rate of terabytes per day from many classes of applications, including simulations running on teraFLOPS-class computers and experimental data produced by increasingly more sensitive and accurate instruments, such as telescopes, microscopes, particle accelerators and satellites. Generating or acquiring data is not an end in itself but a vehicle for obtaining insights. While data analysis and reduction have a role to play, in many situations we achieve understanding only when a human being interprets the data. Visualization has emerged as an important tool for extracting meaning from the large volumes of data that scientific instruments and simulations produce. The authors describe an online system that supports 3D tomographic image reconstruction-and subsequent collaborative analysis-of data from remote scientific instruments.

Basic Issues in the Application of Virtual Reality for the Assessment and Rehabilitation of Cognitive Impairments and Functional Disabilities

Virtual reality (VR) is an emerging computer-driven simulation technology that appears to be well matched to the assessment and rehabilitation needs of persons with cognitive impairments and functional disabilities. Persons with these difficulties due to acquired brain injuries, neurological disorders, and developmental disabilities could benefit from the development of VR testing and training environments. VR technology is capable of delivering cognitive and functional scenarios that allow for complex, dynamic stimulus presentations and the capacity to record and measure all responses precisely within the virtual environment. In this regard, VRs capacity to improve on the experimental control available in these applications is a neuropsychologists dream! However, several basic issues need to be considered for the rational and measured development of VR applications for the study, assessment, and rehabilitation of cognitive impairments and functional disabilities. This article begins with brief introduc...

The Virtual Reality Mental Rotation Spatial Skills Project

Virtual reality (VR) technology offers the potential to create sophisticated new tools that could be applied to the neuropsychological assessment and cognitive rehabilitation of persons with acquir...

Issues for the Assessment of Visuospatial Skills in Older Adults Using Virtual Environment Technology

Virtual Environment (VE) technology offers clinical assessment and rehabilitation options that are currently not available using traditional neuropsychological methods. Advancements in this type of immersive information technology could produce tools that enhance the scientific study of human cognitive/functional processes and improve our capacity to more accurately assess and treat impairments found in persons with central nervous system (CNS) dysfunction. Through the creation of dynamic three-dimensional (3D) stimulus environments, in which all behavioral responding can be recorded, VE technology offers the possibility to more sensitively address a range of age-related CNS disorders including Alzheimers Disease, Vascular Dementia, Parkinsons Disease, and stroke. Advances in this area could impact quality of life issues for an increasingly aging world population. The VE Laboratory at the University of Southern California has developed a suite of ImmersaDesk-format, 3D projection-based VEs. These scenar...

Gender Issues in the Use of Virtual Environments

Gender differences in cognitive and behavioral performance have been reported throughout the psychological literature. Consequently, gender differences should be considered and controlled for when cognitive research is conducted in virtual environments (VEs). These variables may include gender-related differences in cognitive performance, susceptibility for cybersickness, and the impact of sex hormones on cognition. Such issues are addressed in the context of a recent VE study of the visuospatial ability referred to as mental rotation. The Mental Rotation Test (MRT), a paper and pencil measure, has been shown to produce one of the largest gender differences in the cognitive literature. The outcomes of the MRT are in favor of males. However, results reported from a Virtual Reality Spatial Rotation (VRSR) test demonstrate no gender differences when subjects were able to manually manipulate the stimuli in a VE. Further analysis uncovers gender differences in the patterns of associations between verbal and spatial tasks and performance on VRSR. Results are discussed in terms of dimensionality factors and hemispheric lateralization.

Virtual Environments for Assessing and Rehabilitating Cognitive/Functional Performance A Review of Projects at the USC Integrated Media Systems Center

Virtual reality (VR) technology offers new options for the creation of sophisticated tools that could be applied in the areas of assessment and rehabilitation of cognitive and functional processes. VR systems allow for the precise presentation and control of dynamic, multisensory, three-dimensional (3-D) stimulus environments, as well as the recording of all behavioral responses that occur within them. Assessment and rehabilitation scenarios that would be difficult if not impossible to deliver using conventional neuropsychological methods are now being developed that take advantage of these VR assets. If empirical studies demonstrate effectiveness, virtual environments (VEs) could be of considerable value for better understanding, measuring, and treating persons with impairments due to traumatic brain injury, neurological disorders, and learning disabilities. This article describes the progress of a VR research program at the USC Integrated Media Systems Center and Information Sciences Institute that has developed and investigated the use of a series of VEs designed to target (i) molecular visuospatial skills using a 3-D, projection-based ImmersaDesk system, and (ii) attention (and soon memory and executive functioning) processes within ecologically valid functional scenarios utilizing a head-mounted display (HMD). Results from completed research, rationales and methodology of works in progress, and our plan for future work is presented. Our primary vision has been to develop VR systems that target cognitive processes and functional skills that are of relevance to a wide range of patient populations with central nervous system (CNS) dysfunction, as well as for the assessment of unimpaired performance. We have also sought to select cognitive/functional targets that intuitively appear well matched to the specific assets available with currently available VR technology.