Acute caffeine effect on repeatedly measured P300

The acute effect of a single-dose of caffeine on the P300 event-related brain potential (ERP) was assessed in a study using a repeatedly presented auditory oddball button-press task. A dose (5mg/kg body-weight) of either caffeine or placebo lactose, dissolved in a cup of decaffeinated coffee, was administered double-blindly to coffee drinkers who had abstained from coffee for 24hrs, with the presentation order of the sessions counterbalanced and separated by 2–4 weeks. The caffeine-treatment condition demonstrated a smaller P300 amplitude and a shorter latency overall than the placebo treatment condition. The mean P300 amplitude value difference (caffeine minus placebo) increased with the successive trial blocks. Caffeine ingestion appears to yield a lower resource-consumption and a net increase in allocating attention resources for task performance across repeated measurements.