Dean H. Owen

Optical information for detecting loss in one's own forward speed

An experiment was conducted to determine whether accuracy and efficiency of detecting loss in ones own forward speed are constant when optical information is invariant over a wide range of environmental variables. Deceleration rate, initial forward velocity, and altitude were varied so as to isolate initial optical flow rate, optical flow deceleration, and optical flow damping invariants specified in observer-relevant metrics. The candidate resulting in the most consistent effect on performance was global damping, which specifies a contrast of flow deceleration with initial flow rate. The finding is a first step toward validating a procedure for identifying functional invariants by assessing the usefulness of mathematically specified optical information for the perception of egomotion. The research represents both a methodological development and empirical support for the broader program of ecological functionalism.

Bias-Free Improvement in Wine Discrimination

Over three test sessions alternated with two training sessions, accuracy of ‘same’/‘different’ judgments of four dry, white wines improved 14%. Confidence ratings were obtained so that the area under the isosensitivity curve could be computed as a bias-free measure of accuracy while the wine used for same pairs was held constant. An initial bias for ‘different’ judgments persisted, rather than disappearing as Walk found. While perceptual learning did occur, the problem of attending to irrelevant differences was not overcome.

Visual and tactual form discrimination: Psychophysical comparison within and between modalities

Intermodal perceptual equivaience was investigated, using visual and tactual oddity discrimination and cross-modal matching-to-sample tasks. Four groups of Ss were presented with 100 problems made up of randomly derived forms from five levels of sidedness. The same quadratic relationship was observed for all tasks as a function of complexity, with optimal performance at eight sides. Comman information utilization, as indicated by intercorrelations of performance variables and by correlational analyses with differences in form measures, was not as pronounced within side classes. Evidence concerning the nature of pattern-feature usage in discrimination was obtained from graphical analyses.

Perception And Control Of Self-Motion: Implications For Visual Simulation Of Vehicular Locomotion

Few pedestrians have ever died by running into another pedestrian or a tree. Vehicles travel faster than people can run and people do die. Curiously, the perceived speed of self-motion may be alarmingly slow such as experienced in a high flying jet. Further, the same physical speed may be experienced differently, for example, when traveling in a car versus a truck. Still further, the same speed in the same vehicle may appear quite different after traveling several hours on a high-speed road. Because the discrepancy between physical and perceived speeds presumably does lead to fatal accidents, human factors researchers are actively trying to achieve a fundamental understanding of the problem of the perception and control of self-motion. This includes the control of altitude and heading as well as speed. The researchers are also studying ways to prevent accidents during real self-motion by better use of vehicle simulators. Better simulator use refers to their design, to the information they provide, and to the training programs. The general review in this chapter indicates that we do not yet have a sufficient knowledge of the principles of the perception and control of self-motion to satisfactorily deal with the problems at hand. However, several studies are presented in detail from an aviation psychology program which is achieving a union of basic and applied research.

Laterality differences in sensitivity to line orientation as a function of adaptation duration

Since available evidence indicates that the two cerebral hemispheres are differentially sensitive to different types of stimulus information, and that they also utilize different strategies in processing information, is it possible that the two hemispheres are differentially sensitive to adaptation? Three groups of four subjects each were adapted to black and white gratings using three adapting durations: 500, 1,000, and 5,000 msec. Immediately following adaptation, a test grating was presented in either the left or right visual field. The task of the subject was to determine whether the lines of the adapting and test gratings had the same orientation or not. Analysis showed that in the 5,000-msec and 1,000-msec conditions, more errors occurred with left visual field presentations, responses to left visual field presentations took longer, and a bias-free measure showed that subjects were more sensitive to right visual field presentations. For the 500-msec group, there were no apparent differences between left and right visual fields presentations. The results indicate differential effects of adaptation on the two hemispheres, suggesting sensitivity differences between the two halves of the brain.

Visual and tactual form complexity:A psychophysical approach to perceptual equivalence'

Equivalence of two modalities for processing form-complexity information was investigated by obtaining category judgments of the complexity of 100 random forms from 40 Ss who explored the forms visually and 40 Ss who explored them tactually. Intercorrelations of judgments and multiple regression analyses with form measures indicate that information was used in the same fashion independent of input modality. Latencies were interpreted as reflecting information gaining and processing capabilities.

Developmental generality of a form recognition strategy.

Abstract A 5-year-old S performed 1250 trials in a from recognition task requiring S to find a form among 25 others on each trial. Fifty different eight-sided randomly derived polygons were used as forms to be recognized, each presented in 25 different problems. Factors based on physical measures of the forms were correlated with observed latencies using multiple regression to assess an information utilization strategy. Comparisons of the regression profile and correlations of physical measures with latency for the 5-year-old with those for a group of 25 adults indicated that use of form information was highly consistent across age levels.

Central integration effects with stabilized afterimages

Prolonged patterned afterimages were used to study integration effects in stabilized images. Seven Ss were presented with various configurations of a pattern through a prism stereoscope, both monocularly and binocularly. Some of the fragmentations and regenerations reported in the binocular condition could only have resulted as a function of organization of the inputs to the two eyes, suggesting that postretinal processes are operative in stabilized image phenomena.

Form recognition: Individual strategies in multivariate cue utilization

Twenty-five Ss were each presented 1,250 trials in a form-recognition task requiring S to find a form among 25 other forms on each trial. Fifty different eight-sided randomly derived polygons were used as stimuli, each presented in 25 different problems. Factors based on physical measures of the stimuli were correlated with observed latencies using multiple regression to assess cue-utilization strategies, while beta-weight profiles and intercorrelations of the Ss’ predicted latencies were used as indices of individual differences. Multiple correlations of physical-factor scores with observed latencies accounted for a significant proportion of the variance for all Ss, while between-S correlations of predicted latencies were never below .90. By all criteria employed, use of stimulus information was highly consistent among Ss. Replication of the experiment for one S revealed good reliability and nearly identical strategies.

Use of Systemic Theory to Represent the Conceptual Mechanical Design Process

A theoretical framework for representing the mechanical design process based on the use of systemic theory, is presented. The systemic approach is taken since the design process is context dependent and is initially functional in nature. The function-to-form transformation is part of the process. Hence, initially it is the semantic function which is important since the syntactic structure follows from it. Through our observations of the design process, we have found that expert designers often make choices from a set of design options in their experiential repertoire which fit the given problem context. It was observed that the designers identify two types of constraints, namely primary (binding or non-negotiable) and secondary (plastic or negotiable), which they use to set the context and to direct their design. We have taken the systemic functional analogy and defined a set of metafunctions which we believe to be important in describing the conceptual design. The systemic theory representation allows for the use of the problem solving methodology from Artificial Intelligence to generate a system network of the design choices which the designer makes. Identification of the meta-functions allow for the design to be mapped at three levels.