The effect of caffeine use on a visual information processing task

Abstract

AbstractPast caffeine studies have shown that differences in task performance may be due to differences in habitual caffeine consumption levels of individuals. No study has yet investigated this caffeine user effect alone without confounding it with the administration of caffeine. The present study used a visual search/detection task to test whether high caffeine users have an enhanced resource capacity and therefore show higher baseline performance than low and moderate caffeine users. A three‐way interaction between caffeine user (low, moderate, and high caffeine user), automaticity (automatic and non‐automatic), and task difficulty (low and high) was predicted, with user effect significant for the non‐automatic portion of the task. The three‐way interaction was not significant, suggesting that user effect is not dependent on resource capacity. Several interpretations, based on theoretical, empirical, methodological, and statistical viewpoints, are discussed as to the non‐significant caffeine user effect.