Brian P. Dyre

Image velocity magnitudes and perception of heading.

Most theoretical approaches to perception of heading rely on the directions of image velocity vectors as the primary source of heading information. The research described in this article examined an additional source of information for determining heading: distributions of image velocity magnitudes. Displays simulated observer motion relative to rigid three-dimensional environments. Depth was distributed nonuniformly such that image velocity magnitudes provided, for some display conditions, conflicting heading information relative to the radial directions of the flow field. Results indicated that image velocity magnitudes influenced heading performance, suggesting that the perception of heading is not based solely on the radial structure of the directions of image flow.

Eye Fixation Durations in Reading: Models of Frequency Distributions

Abstract Quantitative versions of three models of fixation-duration frequency distributions are presented: those proposed by Suppes (1989), McConkie, Kerr and Dyre (1994) and a modified version of that proposed by Harris, Hainline, Abramov, Lemerise and Camenzuli (1988). These, plus two additional versions of the Harris et al. model, were fit to a large set of eye-movement data from a group of adult readers. The McConkie et al. model fit the data best, though the fit appears to result primarily from the functions used rather than from the architecture proposed.

Understanding bias in proportion production.

The Stevens exponent (beta) can be obtained from proportion estimation judgments using the power model. In this article, the authors extend that model to proportion production, in which the relative magnitudes of 2 stimuli are adjusted to correspond to a numeric proportion (e.g., 1/4 or .25). The model predicts that when beta < 1, small proportions are underproduced, and large proportions are overproduced, but it predicts the reverse when beta > 1, which is the opposite of the predicted patterns for estimation. Eight participants estimated and produced magnitudes and proportions with spatial volume (beta < 1; Experiment 1) and color saturation (beta > 1; Experiment 2). The models predictions were generally supported. An extension of the model using reference points can account for multicycle patterns shown by some participants.

A Microworld Simulator for Process Control Research and Training

We introduce and will demonstrate a new software tool for creating simulations of simplified process control tasks—what Vincente (2000) termed microworlds—for research and training applications. This tool builds on previous software tools, such as the synthetic task environment DURESS, but provides more flexibility in simulation design, a more realistic physics model, and additional components for representing complex processes, such as auditory and visual alarms for nuclear power plants. Further, our microworld simulation tool can be used for a variety of tasks, from flexibly specifying a synthetic environment for research on a desktop computer to scaling up to large format touch displays with realistic controls typical of high-fidelity process control simulators. Potential applications of the microworld simulator include research on the cognitive engineering of human-machine interfaces used in process control, training of process control operators and other personnel, and rapid prototyping and testing of process controls and displays.

Fault Diagnosis with Multi-State Alarms in a Nuclear Power Control Simulator

This research addresses how alarm systems can increase operator performance within nuclear power plant operations. The experiment examined the effect of two types of alarm systems (two-state and three-state alarms) on alarm compliance and diagnosis for two types of faults differing in complexity. We hypothesized three-state alarms would improve performance in alarm recognition and fault diagnoses over that of two-state alarms. We used sensitivity and criterion based on Signal Detection Theory to measure performance. We further hypothesized that operator trust would be highest when using three-state alarms. The findings from this research showed participants performed better and had more trust in three-state alarms compared to two-state alarms. Furthermore, these findings have significant theoretical implications and practical applications as they apply to improving the efficiency and effectiveness of nuclear power plant operations.

An Implementation of a Graded Deceleration Display in Brake Light Warning Systems

The purpose of this research is to assess the effectiveness of the Graded Deceleration Display (GDD) that is designed to replace the rear center high mounted stop lamp on automobiles. Licensed drivers were treated in simulation to both a standard brake light displays (binary) and the GDD display while the lead vehicle (LV) varied its deceleration magnitude and ramping behavior. Results entailed that the graded system produced more accurate behavioral responses during deceleration, fewer collisions, and a safer following distance than the binary system. Future research should be concerned with solidifying this framework so that it can be used to improve safety, effectiveness, and efficiency for vehicle transportation.

Conjunction benefits and costs reveal decision priming for first-order and second-order features.

Across two experiments, decision priming was examined for conjunctions composed of first-order or first- and second-order stimulus features. Observers indicated the presence or absence of one or two features in a Gabor stimulus. When a pair of stimulus features differed in their speed of discrimination, responses indicating the presence of a conjunction were faster than those for the single feature for which discrimination was slowest (conjunction benefits). Also, responses indicating the absence of a conjunction were delayed if one of the features was present (conjunction costs). These results show that first- and second-order features can prime decisions about the presence of a conjunction and suggest that the two kinds of signals can be combined at a decision stage after the discrimination of stimulus properties has begun for each system.

Assessing Mental Workload from Skin Conductance and Pupillometry using Wavelets and Genetic Programming

An essential component of augmented cognition (AC) is developing robust methods of extracting reliable and meaningful information from physiological measures in real-time. To evaluate the potential of skin conductance (SC) and pupil diameter (PD) measures, we utilized a dual-axis pursuit tracking task where the control mappings repeatedly and abruptly rotated 90° throughout the trials to provide an immediate and obvious challenge to proper system control. Using these data, a model-building technique novel to these measures, genetic programming (GP) with scaled symbolic regression and Age Layered Populations (ALPS), was compared to traditional linear discriminant analysis (LDA) for predicting tracking error and control-mapping state. When compared with traditional linear modeling approaches, symbolic regression better predicted both tracking error and control mapping state. Furthermore, the estimates obtained from symbolic regression were less noisy and more robust.

Active heading control in simulated flight based on vertically extended contours

In two experiments, we manipulated the properties of 3-D objects and terrain texture in order to investigate their effects on active heading control during simulated flight. Simulated crosswinds were used to introduce a rotational component into the retinal flow field that presumably provided the visual cues used for heading control. An active control task was used so that the results could be generalized to real-world applications such as flight simulation. In Experiment 1, we examined the effects of three types of terrain, each of which was presented with and without 3-D objects (trees), and found that the presence of 3-D objects was more important than terrain texture for precise heading control. In Experiment 2, we investigated the effects of varying the height and density of 3-D objects and found that increasing 3-D object density improved heading control, but that 3-D object height had only a small effect. On the basis of these results, we conclude that the vertical contours improved active heading control by enhancing the motion parallax information contained in the retinal flow.

A Peripherally-Located Virtual Instrument Landing Display Affords More Precise Control of Approach Path during Simulated Landings than Traditional Instrument Landing Displays

We compared the precision of simulated fixed-wing aircraft landing approaches with three different head-up display (HUD) formats: a) MIL-STD-1787B Cruise Mode, b) MIL-STD-1787B Instrument Landing System (ILS) Mode, and c) a virtual ILS HUD presented to the visual periphery. Non-pilot participants used simplified controls to guide a landing simulation under both day and night visual meteorological conditions. Experiment 1 confirmed that testing non-pilots with our experimental setting could induce the black-hole illusion, in which the approach is lower than appropriate at night. Experiment 2 compared landing performance aided by the three HUD formats under the same visual conditions. We found that both ILS displays improved approach path precision as compared to the MIL-STD Cruise Mode, and that the peripherally-located virtual ILS HUD reliably afforded the greatest precision. These results suggest that ILS approaches may be better supported by presenting a virtual ILS display to the visual periphery.