title: Waiting Impulsivity: The Influence of Acute Methylphenidate and Feedback.
abstract: BACKGROUND
  The ability to wait and to weigh evidence is critical to behavioral regulation. These behaviors are known as waiting and reflection impulsivity. In Study 1, we examined the effects of methylphenidate, a dopamine and norepinephrine reuptake inhibitor, on waiting and reflection impulsivity in healthy young individuals. In study 2, we assessed the role of learning from feedback in disorders of addiction.
  
  
  METHODS
  We used the recently developed 4-Choice Serial Reaction Time task and the Beads task. Twenty-eight healthy volunteers were tested twice in a randomized, double-blind, placebo-controlled cross-over trial with 20mg methylphenidate. In the second study, we analyzed premature responses as a function of prior feedback in disorders of addiction.
  
  
  RESULTS
  Study 1: Methylphenidate was associated with greater waiting impulsivity to a cue predicting reward along with faster responding to target onset without a generalized effect on reaction time or attention. Methylphenidate influenced reflection impulsivity based on baseline impulsivity. Study 2: More premature responses occurred after premature responses in stimulant-dependent subjects.
  
  
  CONCLUSIONS
  We show that methylphenidate has dissociable effects on waiting and reflection impulsivity. Chronic stimulant exposure impairs learning from prior premature responses, suggesting a failure to learn that premature responding is suboptimal. These findings provide a greater mechanistic understanding of waiting impulsivity.
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison). vv247@cam.ac.uk.
authors.forename: Valerie
authors.initials: V
authors.lastname: Voon
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Yee Chien
authors.initials: YC
authors.lastname: Chang-Webb
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Laurel S
authors.initials: LS
authors.lastname: Morris
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Ella
authors.initials: E
authors.lastname: Cooper
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Arjun
authors.initials: A
authors.lastname: Sethi
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Kwangyeol
authors.initials: K
authors.lastname: Baek
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Jon
authors.initials: J
authors.lastname: Grant
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Robbins
authors.affiliation: Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Dr Voon, Ms Chang-Webb, Ms Morris, Ms Cooper, Mr Sethi, Dr Baek, Dr Robbins, and Dr Harrison); Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom (Dr Voon, Ms Morris, and Dr Robbins); Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom (Dr Voon); Department of Psychology, University of Cambridge, Cambridge, United Kingdom (Ms Morris and Dr Robbins); Department of Psychiatry, Brighton and Sussex Medical School, Brighton, United Kingdom (Ms Cooper, Mr Sethi, and Dr Harrison); Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, IL (Dr Grant); Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom (Dr Harrison); Sussex Partnership NHS Trust, Brighton, United Kingdom (Dr Harrison).
authors.forename: Neil A
authors.initials: NA
authors.lastname: Harrison
mesh_terms: D000704:Analysis of Variance; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D002755:Choice Behavior / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D030141:Feedback, Psychological / Q000187:drug effects*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007175:Impulsive Behavior / Q000187:drug effects*; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology*; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance; D011930:Reaction Time / Q000187:drug effects; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: addiction; binge drinking; impulsivity; methylphenidate; premature responding; stimulant dependence