Acute effects of caffeine on behavioural and ERP indices of attention in healthy, low consumers of caffeine

Caffeine is commonly used to enhance attentional processes. However, contention remains regarding the extent to which each attentional mechanism is affected by caffeine, and whether caffeine enhances attention over-and-above improvements in general arousal and sustained attention. Subsequently, the present study examined the acute effects of caffeine on behavioural (reaction time & accuracy) and electrophysiological (N1 ERP amplitude) measures of attention. During two separate sessions (separated by 7-14 days), twenty (14 female & 6 male) healthy, low consumers of caffeine (<150mg/day) completed an Attentional Network Task prior to ingesting either caffeine (200mg) or placebo, and again 30-minutes following ingestion. While a partial effect of caffeine upon the alerting and executive control networks was found, results of the present study suggested improvements in reaction time and accuracy following caffeine predominantly reflected a maintenance of general arousal and tonic alertness. It was concluded that caffeine primarily enhanced attentional processing by preventing fatigue and sustaining attention.