Feasibility of the Use of Eye Movement Data in the Analysis of Neurobehavioral Test Performance

Abstract

Better understanding of the functions and abilities underlying some neurobehavioral tests would assist the assessment of the consequences to the health or well-being of exposed populations for which decrements in such tests have been found. Eye movements, which can be useful in evaluating specific theories of visual and cognitive processes, were measured while a single participant completed the NES Symbol-Digit Substitution test. Relationships between the durations and the frequencies of eye fixations within different parts of the test material and overall test performance were examined. The overall pattern of eye-movement behavior observed was as predicted: fixations within three regions of visual interest were made, usually in the order lower matrix, upper matrix, keyboard. Both the upper matrix fixation latency and the number of regional fixations made per item were found to be strongly associated with overall item response latency. This suggests that speed and efficiency of searching and the ability to maintain concentration appeared to be key attributes related to test performance for this participant. For suitable tests, eye-movement data may be useful for assessing and measuring the latencies of subtask components in a real test situation. Monitoring eye movement represents an alternative methodology to using sub test composites, or factor analysis, as a means of tapping into the functions underlying neurobehavioral test performance.