SENSE MODE AND COUPLING IN A VIGILANCE TASK
Abstract
The investigation examined the performance of thirty-six subjects on three 90-minute vigilance tasks. Response measures for signals were available in three basic forms: hits, false alarms, and response latency. In addition, parameters of signal detection, decreased sensitivity ('d') and observer's criteria (beta) were derived from the data. There was a significant decrease in hits and false alarms with increasing time on task, regardless of sense mode and coupling conditions, or the number of signal intensities. In general, when detection rate decreased, reaction time increased. The consistent sequential relationship between the stimulus conditions suggests that there are uniform trends among conventional response measures. There was a significant decline in sensitivity (d') with increasing time on task for the closely coupled tasks, regardless of sense mode involved, but d' remained fairly stable for the loosely coupled visual task. In this experiment, beta values increased significantly for all vigilance tasks. There is a tendency, therefore, for the observer to adopt a more conservative mode of responding with increasing time on task. Orthogonal comparisons of that portion of the variance due to stimulus conditions clearly establish coupling effects as a critical independent variable. Numerous significant correlation coefficients of vigilance performance are reported and current methodological problems associated with this area of research are discussed in detail.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 18, 1967
- Accession Number
- AD0664760
Entities
People
- Jimmy L. Hatfield
- Michel Loeb
Organizations
- United States Army Medical Research Laboratory