Effects of caffeine on visual monitoring

Abstract

Examined the effects of caffeine on a protracted visual monitoring task analogous to an aspect of automobile night driving. 100 male undergraduates participated in monitoring 2 red lights that moved apart at random intervals, simulating the rate-of-closure cue of change in visual angle for a vehicle following 60 yd. behind another vehicle. 20 measures of response latency were provided for each S in each of 4 hr. of continuous testing. 5 groups (n = 20) were given the following treatments: placebo, 200 mg. of caffeine at the beginning of the 2nd hr., 200 mg. at the 3rd hr., 400 mg. at the 2nd, and 400 mg. at the 3rd. Results indicate that caffeine significantly inhibited response blocking (attention lapses). The effects were apparent within l hr. following administration and persisted over the remaining time. No difference was found between dosage levels or in magnitude of effect at the different administration times. (PsycInfo Database Record (c) 2025 APA, all rights reserved)