The role of memory representation in the vigilance decrement

Abstract

Working memory load is critically important for the overall level of performance on vigilance tasks. However, its role in a key aspect of vigilance - sensitivity decrement over time - is unclear. We used a dual-task procedure in which either a spatial or a nonspatial working memory task was performed simultaneously with a spatial vigilance task for 20 min. Sensitivity in the vigilance task declined over time when the concurrent task involved spatial working memory. In contrast, there was no sensitivity decrement with a nonspatial working memory task. The results provide the first evidence of a specific role for working memory representation in vigilance decrement. The findings are also consistent with a multiple resource theory in which separate resources for memory representation and cognitive control operations are differentially susceptible to depletion over time, depending on the demands of the task at hand. Copyright 2004 Psychonomic Society, Inc.