Randy J. Brou

Individual Differences in Object Localization in Virtual Environments

The present research examined the effects of disorientation on human ability to locate objects in space in a virtual environment (VE). Participants were asked to memorize the location of virtual objects, and then they were asked to indicate where the objects were located while they were inside a virtual chamber. This procedure was repeated in both eyesclosed and disoriented conditions. Subject pointing responses were used to measure memory for the relative location of objects in virtual space. This method was extended from previous research in a real-world setting. The results showed systematic individual differences in the effects of disorientation on the ability to locate objects in space. Further, the use of strategies played a role in object localization ability, but strategy use was affected by the individual differences in spatial representations used by subjects.

The Role of Individual Differences in Dynamic Team Performance

Teams often operate in dynamic task environments where the state of the world and the coordinative requirements for optimal performance change rapidly. To build effective teams, it is important to know what factors influence team performance. The present research investigates several factors that may influence team performance in dynamic environments. In this study, participants first completed a battery of cognitive and non-cognitive tests. Results of the tests were used to form three-person teams with varying levels of ability. Team performance was scored in 12 dynamic tasks. Individual differences in cognitive ability and personality characteristics were then used to predict team-level performance. Results indicate that two team member characteristics, cognitive ability and stress tolerance, are important to dynamic task performance, while other characteristics such as achievement motivation play roles in specific circumstances. Implications of these results are discussed

Adaptive Expertise during Simulated Flight

The present research examined pilot ability to perform simulated flight maneuvers in routine and nonroutine instrument flight situations as a function of expertise. Twenty-one pilots were asked to fly nine simulated instrument flight maneuvers using a modified version of Microsoft Flight Simulator©. Each of the flight maneuvers involved performing routine control movements on up to three axes (airspeed, altitude, and/or heading). For the first seven trials, all instruments operated properly. During the final two trials, the attitude indicator experienced a partial vacuum failure that was either announced or unannounced. Pilot control movements, eye fixations, and flight status were recorded. Percent goal completion within specified bounds (commercial pilot standards) was calculated for each trial. Eye fixations were not analyzed. The results indicated an overall expertise effect for routine flight. However, during unannounced failure, expert performance dropped to novice levels. The results are discussed in terms of training and routine versus adaptive expertise.

Real-time generation of representations for cognitive models

Computerized models of human cognition and behavior have been used to help researchers refine their theories of cognitive processes. Two difficulties inherent in using these cognitive models are that building representations of to-be-modeled groups or individuals is (1) time-consuming and (2) prone to error when performed manually. The use of computerized tools to build representations for cognitive models could alleviate these problems. Such a set of tools has been developed and applied to the task of modeling individual aviation pilots performing flight maneuvers in real time. A study conducted with 27 pilots confirms the accuracy of the computer-generated representations.

Pilot Expertise and Instrument Failure: Detecting Failure is Only Half the Battle

The present research examined novice and expert flight performance in simulated routine and announced instrument failure flight conditions. Pilots flew routine flight segments under simulated instrument flight rules, and were informed there would be an instrument failure at some point. Microsoft Flight Simulator was used to simulate a slow vacuum failure that impacted the attitude indicator and the failure was explicitly displayed in large letters on the instrument panel throughout the failure segment. Although novices and experts showed minimal axis deviations from optimal during routine flight maneuvers, the novice deviations increased significantly in the announced failure condition. The results have implications for the efficacy of instrument failure indicators for novice pilots with approximately ninety-five hours of flight experience.

Optimizing Training for Visual Discrimination Across Stimulus Categories

Discriminating between stimuli is a component of many complex tasks such as radar operations and flying an F-16. Previous research suggests that initial training difficulty may influence the acquisition and transfer of strategic discrimination skills for such tasks. The current research examined the extent to which strategies acquired during initial training may be transferred to novel stimuli. Participants were trained to discriminate between similar (difficult training) or dissimilar (easy training) stimuli and then were required to discriminate between completely novel stimuli. Of specific interest were the effects of strategic skills acquired in a difficult- or easy-training context on inter-categorical transfer performance. The results provided further evidence that initial training difficulty influences strategic skill acquisition and suggest that strategic skills are applied at transfer, even to a completely novel category of stimuli. The implications of this research are discussed in the context of learning theories and training.

Volume visualization of 5D sedimentation models

We implemented a hybrid immersive visualization system for a five dimensional (5D) coupled bottom boundary layer-sedimentation model. This model predicts sediment resuspension, transport, and resulting distributions for shallow water regions on continental shelves. One variable of interest, suspended sediment concentration (SSC), is 5D and varies by longitude, latitude, depth, time, and grain size. At each grid point there are twenty values for SSC, representing grain sizes ranging from 2.36 to 3306 micrometers . Currently the most common methods of analyzing the SSC distribution are only 2D, e.g., point profiles, cross-sections, map views at equal water depths, and time series. Traditional methods require multiple sets of plots that are analyzed manually. Good 3D methods are needed that will allow researchers to investigate the complex relationships between variables and see the underlying physical processes more comprehensively, especially within the wave boundary layer close to the ocean bottom. This paper presents the work in progress on the motivation, requirements, and overall design of the visualization system, along with the latest efforts to incorporate volume visualization as an effective means of understanding the SSC variable. The system is optimized for deployment in a CAVE. We also describe the extension of this system to other problem domains.

Effects of Disorientation on Human Spatial Cognition: Object Localization in Virtual Environments

The present research examines the effects of disorientation on human ability to locate objects in space in a virtual environment (VE). Participants were asked to memorize the location of virtual objects. After memorizing object locations, they were asked to indicate where the objects were located while inside a virtual chamber. This procedure was repeated in eyes-closed and disoriented conditions. Subject pointing responses were used to measure memory for the relative location of objects in virtual space. This method was extended from Wang and Spelkes (2000) research in a real-world setting. The results show systematic individual differences in the effects of disorientation on the ability to locate objects in space. Two groups of subjects, initially disoriented in the eyes-closed condition, use a memory strategy to locate objects, while another group, less easily disoriented in eyes-closed, shows degraded performance in the disorientated condition. The results are discussed with respect to configural and egocentric theories of spatial cognition.