title: Neural effects of methylphenidate and nicotine during smooth pursuit eye movements.
abstract: BACKGROUND
  Nicotine and methylphenidate are putative cognitive enhancers in healthy and patient populations. Although they stimulate different neurotransmitter systems, they have been shown to enhance performance on overlapping measures of attention. So far, there has been no direct comparison of the effects of these two stimulants on behavioural performance or brain function in healthy humans. Here, we directly compare the two compounds using a well-established oculomotor biomarker in order to explore common and distinct behavioural and neural effects.
  
  
  METHODS
  Eighty-two healthy male non-smokers performed a smooth pursuit eye movement task while lying in an fMRI scanner. In a between-subjects, double-blind design, subjects either received placebo (placebo patch and capsule), nicotine (7mg nicotine patch and placebo capsule), or methylphenidate (placebo patch and 40mg methylphenidate capsule).
  
  
  RESULTS
  There were no significant drug effects on behavioural measures. At the neural level, methylphenidate elicited higher activation in left frontal eye field compared to nicotine, with an intermediate response under placebo.
  
  
  CONCLUSIONS
  The reduced activation of task-related regions under nicotine could be associated with more efficient neural processing, while increased hemodynamic response under methylphenidate is interpretable as enhanced processing of task-relevant networks. Together, these findings suggest dissociable neural effects of these putative cognitive enhancers.
authors.affiliation: Department of Psychology, University of Bonn, Bonn, Germany.
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Kasparbauer
authors.affiliation: Department of Psychology, University of Bonn, Bonn, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Meyhöfer
authors.affiliation: Department of Psychology, University of Bonn, Bonn, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Steffens
authors.affiliation: Center for Economics and Neuroscience, University of Bonn, Bonn, Germany; Department of Epileptology, University Hospital Bonn, Bonn, Germany; Department of NeuroCognition/Imaging, Life & Brain Center, Bonn, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Weber
authors.affiliation: Department of Psychiatry and Division of Medical Psychology, University of Bonn, Bonn, Germany.
authors.forename: Merve
authors.initials: M
authors.lastname: Aydin
authors.affiliation: Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, UK; National Institute for Health Research Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust, London, UK.
authors.forename: Veena
authors.initials: V
authors.lastname: Kumari
authors.affiliation: Department of Psychiatry and Division of Medical Psychology, University of Bonn, Bonn, Germany.
authors.forename: Rene
authors.initials: R
authors.lastname: Hurlemann
authors.affiliation: Department of Psychology, University of Bonn, Bonn, Germany. Electronic address: ulrich.ettinger@uni-bonn.de.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Ettinger
mesh_terms: D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage*; D009039:Motion Perception / Q000187:drug effects / Q000502:physiology; D009538:Nicotine / Q000008:administration & dosage*; D018697:Nootropic Agents / Q000008:administration & dosage; D015990:Placebo Effect; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology*; D011698:Pursuit, Smooth / Q000187:drug effects* / Q000502:physiology*; D016896:Treatment Outcome; D014794:Visual Fields / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D018697:Nootropic Agents; D008774:Methylphenidate; D009538:Nicotine
keywords: Cognitive enhancer; Eye movement; Methylphenidate; Nicotine; Smooth pursuit; fMRI