title: Methylphenidate (MPH) promotes visual cortical activation in healthy adults in a cued visuomotor task.
abstract: Seeking for the mechanisms by which methylphenidate (MPH) improves behavior has demonstrated that MPH modulates excitability in the primary motor cortex. However, little is known about the influence of MPH on top-down controlled mechanisms in the sensory domain. The present study explored the effects of MPH on the activation of visual cortices in healthy adults who performed a cued visuo-motor task in a double-blind placebo-controlled crossover design. Two distinct measures, posterior alpha power and occipital slow cortical potentials (SCPs), were used to reflect raise in excitability and attention-based activation of visual cortical areas. According to the results, performance parameters (reaction time, response variance and error rate) were not affected by MPH. At the neurophysiologic level reflected by reduced alpha power, MPH increased the overall excitability of the occipital cortex, but not the parietal cortex. Before the cued response, MPH reduced alpha power and increased SCPs only before right hand responses, mostly at the right occipital location. It can be concluded that in visuo-motor tasks, MPH has the potency of adjusting the background excitation/inhibition balance of visual areas. Additionally, MPH may raise the attention controlled activation of visual cortical regions, especially during increased response control.
authors.affiliation: Institute of Neurobiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
authors.forename: Yordan
authors.initials: Y
authors.lastname: Hodzhev
authors.forename: Juliana
authors.initials: J
authors.lastname: Yordanova
authors.forename: Martin
authors.initials: M
authors.lastname: Diruf
authors.forename: Oliver
authors.initials: O
authors.lastname: Kratz
authors.forename: Gunter H
authors.initials: GH
authors.lastname: Moll
authors.forename: Vasil
authors.initials: V
authors.lastname: Kolev
authors.forename: Hartmut
authors.initials: H
authors.lastname: Heinrich
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003463:Cues; D004311:Double-Blind Method; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000187:drug effects*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology*; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology; D011930:Reaction Time / Q000187:drug effects; D014793:Visual Cortex / Q000187:drug effects* / Q000502:physiology; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate