Methylphenidate promotes the interaction between motor cortex facilitation and attention in healthy adults: A combined study using event-related potentials and transcranial magnetic stimulation

Abstract

Objective: This study investigated simultaneously the impact of methylphenidate (MPH) on the interaction of inhibitory and facilitative pathways in regions processing motor and cognitive functions. Method: Neural markers of attention and response control (event-related potentials) and motor cortical excitability (transcranial magnetic stimulation) and their pharmacological modulation by MPH were measured simultaneously in a sample of healthy adults (n = 31) performing a cued choice reaction test. Results: Methylphenidate modulated attentional gating and response preparation processes (increased contingent negative variation) and response inhibition (increased nogo P3). N1, cue- and go-P3 were not affected by MPH. Motor cortex facilitation, measured with long-interval cortical facilitation, was increased under MPH in the nogo condition and was positively correlated with the P3 amplitude. Conclusion: Methylphenidate seems particularly to enhance response preparation processes. The MPH-induced increased motor cortex facilitation during inhibitory task demands was accompanied by increased terminal response inhibition control, probably as a compensatory process.