The effects of lunch on cognitive vigilance tasks

Abstract
An experiment was carried out to investigate the effects of lunch on cognitive vigilance tasks. Subjects who ate lunch prior to testing detected fewer targets in a paced, successive comparison task, but did not show impaired performance on a proportion perception task. The experiment also demonstrated some differences between morning and afternoon performance in subjects who abstained from eating lunch. This shows that performance changes observed in the early afternoon may be attributed to at least two components. The first of these is meal-dependent, whereas the second is endogenous, and occurs even when lunch is not consumed.