Measuring Sustained Attention and Perceived Workload

Abstract

Objective:

We examined the effects of spatial uncertainty, field dependence/independence (FD/I), and sex on vigilance performance and perceived workload in elementary school children.

Background:

Building on previous work in which children demonstrated their ability to evaluate workload, we tested whether spatial-uncertainty manipulations in a vigilance task would elicit in children the same deleterious effects on performance and workload as it does with adults. We also examined individual difference effects associated with FD/I and sex to determine their influence on both performance and workload.

Method:

In the low-uncertainty task, stimuli appeared in the center of the computer screen; in the high-uncertainty task, they appeared in one of the four quadrants of the screen. Neutral events consisted of uppercase letter strings. Critical signals consisted of a single lowercase letter among uppercase letters. Following each vigil, children completed a workload assessment via a modified version of the NASA Task Load Index.

Results:

Children showed lower perceptual sensitivity, greater response latency variability (RT^SD), and a higher response criterion in the uncertain display condition. Workload scores reflected these performance differences. Field-dependent children showed lower perceptual sensitivity and greater RT^SD than did field-independent children. The two groups exhibited differing workload profiles. Despite no objective performance differences, boys reported greater workload than girls.

Conclusion:

The scale demonstrated sensitivity and diagnosticity with regard to both the task variable and individual differences.

Application:

These findings contribute to the emerging field of “educational ergonomics” and indicate that appropriate assessment tools might identify children who are experiencing increased workload.