The influence of caffeine on sustained attention: An ERP study

The present study investigated the effects of caffeine on sustained attenti on by measuring concentration and fatigue. Event-related potentials (ERPs) and behavioral measures were recorded from 12 participants who worked conti nuously for approximately 10 min in a self-paced reaction task under condit ions of both caffeine (250 mg) and placebo. The ERP data revealed more posi tive frontal P2 and parietal P3 components in the caffeine condition. Howev er, a combination of different indices of the behavioral data did not revea l any effects of caffeine intake. These results suggest that caffeine incre ases arousal, thereby reducing fatigue, as was observed in the ERP results. A probable explanation for the absence of any effects of caffeine in the b ehavioral data can be found in the demanding properties of the task that wa s used, thereby supporting evidence for more pronounced effects of caffeine in suboptimal conditions. In addition, these results appeal for an increas e in the use of ERPs in drug research, in order to discover possible effect s on the brain which do not necessarily result in behavioral changes. (C) 2 000 Elsevier Science Inc.