title: Stimulating cognition in schizophrenia: A controlled pilot study of the effects of prefrontal transcranial direct current stimulation upon memory and learning.
abstract: Schizophrenia is characterized by prominent cognitive deficits, impacting on memory and learning; these are strongly associated with the prefrontal cortex.
  
  
  
  To combine two interventions, transcranial direct current stimulation (tDCS) over the prefrontal cortex and cognitive training, to examine change in cognitive performance in patients with schizophrenia.
  
  
  
  A double blind, sham-controlled pilot study of 49 patients with schizophrenia, randomized into real or sham tDCS stimulation groups. Subjects participated in 4 days of cognitive training (days 1, 2, 14, 56) with tDCS applied at day-1 and day-14. The primary outcome measure was change in accuracy on working memory and implicit learning tasks from baseline. The secondary outcome measure was the generalization of learning to non-trained task, indexed by the CogState neuropsychological battery. Data analysis was conducted using multilevel modelling and multiple regressions.
  
  
  
  24 participants were randomized to real tDCS and 25 to sham. The working memory task demonstrated a significant mean difference in performance in the tDCS treatment group: at day-2 (b = 0.68, CI 0.14-1.21; p = 0.044) and at day-56 (b = 0.71, 0.16-1.26; p = 0.044). There were no significant effects of tDCS on implicit learning. Trend evidence of generalization onto untrained tasks of attention and vigilance task (b = 0.40, 0.43-0.77; p = 0.058) was found.
  
  
  
  This is the first study to show a significant longer-term effect of tDCS on working memory in schizophrenia. Given the current lack of effective therapies for cognitive deficits, tDCS may offer an important novel approach to modulating brain networks to ameliorate cognitive deficits in schizophrenia.
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom. Electronic address: natasza.nalesnik@kcl.ac.uk.
authors.forename: Natasza D
authors.initials: ND
authors.lastname: Orlov
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom; Oxleas National Health Service (NHS) Trust, London, United Kingdom.
authors.forename: Derek K
authors.initials: DK
authors.lastname: Tracy
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom; South London and Maudsley NHS Trust, London, United Kingdom.
authors.forename: Daniel
authors.initials: D
authors.lastname: Joyce
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
authors.forename: Shinal
authors.initials: S
authors.lastname: Patel
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
authors.forename: Joanna
authors.initials: J
authors.lastname: Rodzinka-Pasko
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
authors.forename: Hayley
authors.initials: H
authors.lastname: Dolan
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Hodsoll
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
authors.forename: Tracy
authors.initials: T
authors.lastname: Collier
authors.affiliation: Institute of Neurology, University College London, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Rothwell
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom; South London and Maudsley NHS Trust, London, United Kingdom.
authors.forename: Sukhwinder S
authors.initials: SS
authors.lastname: Shergill
mesh_terms: D000328:Adult; D001288:Attention; D003071:Cognition; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D010865:Pilot Projects; D017397:Prefrontal Cortex / Q000502:physiology; D012559:Schizophrenia / Q000628:therapy*; D065908:Transcranial Direct Current Stimulation / Q000009:adverse effects* / Q000379:methods
keywords: Cognition; Memory; Neuromodulation; Psychosis; Schizophrenia; tDCS