Effects of caffeine on P300: A systematic review and meta-analysis

Caffeine is a widely consumed psychoactive substance that stimulates the central nervous system, enhancing alertness and concentration. Its effects on brain activity can be examined using neurophysiological techniques such as event-related potentials, with emphasis on the P300 component. Caffeine appears to modulate P300 amplitude and latency, suggesting changes in processing speed and attention, although findings remain inconsistent. The objective of this work was to systematise the literature about the effects of caffeine on the amplitude and latency of the P300.

A systematic review and meta-analysis of empirical studies measuring the effect of caffeine on P300 amplitude and latency was conducted, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Statistical analyses were performed using the meta-analysis package for R.

Caffeine intake between 201 and 399 mg was associated with a significant increase in P300 amplitude across anterior, central, and posterior regions, whereas higher doses were associated with smaller effect sizes. No significant differences in P300 latency were observed between pre- and post-caffeine intake.

Overall, our findings align with previous reviews showing that caffeine, as a stimulant, can modulate brain activity. The main limitation of this work is the high heterogeneity across studies. Future research directions are discussed.