The acute effects of modafinil on behavioural and ERP measures of attention

Modafinil is a wakefulness-promoting drug increasingly used off-label for cognitive neuroenhancement in healthy persons, despite conflicting empirical support. The present study aimed to investigate the effects of 200mg of modafinil on behavioural (reaction time and accuracy) and neural (N1 ERP component) measures of attentional alerting and orienting in healthy humans using a Revised Attentional Network Task paradigm. Healthy non-sleep deprived males (N=18) completed the task at baseline and 3 hours post-ingestion (single dose 200mg modafinil or placebo) in this randomised, double-blind, counterbalanced, within-subjects study. They self-reported mood (Profile of Mood States ‚Äö- Short Form), fatigue (Karolinska Sleepiness Scale) and Subjective Performance and Drug Effects (Visual Analogue Scales). The results indicated that modafinil prevented feelings of fatigue experienced in the placebo condition, enhancing both tonic and phasic alerting attention, as indicated by increased N1 amplitude and reduced RT for no cue and central cue trials. Some enhancement of the orienting network (RT and N1 to spatial cues) was observed, but it was of no greater in magnitude than the alerting effects. Therefore, the orienting effect was likely a consequence of the interdependent nature of the networks. These results are a preliminary indication of the positive effect of modafinil on alerting components of attention in healthy persons. Future research should aim to further substantiate these findings, as the current study was slightly underpowered. Studies should also investigate tentative evidence discovered for enhancement of the executive attentional network, indicated by improved inhibition of incongruent flankers.