Sensory and Cognitive Vigilance: Effects of Age on Performance and Subjective Workload

Abstract

Abstract Sensory and cognitive vigilance were compared as a function of age, subjec- tive workload response, and event rate. Sensory and cognitive differences were directly evaluated in the same subjects by using tasks having the same stimuli (digits) equated for presession performance levels and differing only in the type of discrimination required for target detection. Over the course of a 32- min vigil, detection rate for the sensory task showed the normal vigilance dec- rement, whereas the detection rate for cognitive task performance remained stable. However, the decrease in hit rate with an increase in event rate was more pronounced for the cognitive than for the sensory task. Older adults had lower detection rates than younger adults for both tasks and higher false alarm rates for the sensory but not the cognitive task. Subjective workload was rated at relatively high levels and increased significantly from pretest to posttest. The cognitive task was rated as higher in workload than the sensory task. These results are discussed in relation to three issues: (a) implications of sensory and cognitive differences for a vigilance taxonomy, (b) workload de- mands of monitoring tasks, and (c) age differences in vigilance.