title: Transcranial direct current stimulation over the left dorsolateral prefrontal cortex modulates auditory mismatch negativity.
abstract: OBJECTIVE
  To investigate the contribution of the left dorsolateral prefrontal cortex (DLPFC) to attentive and pre-attentive stimulus discrimination via transcranial direct current stimulation (tDCS).
  
  
  METHODS
  Novelty- and target-P3 as indexes of attentive stimulus discrimination and the mismatch negativities (MMNs) for duration, intensity, and frequency deviants as indexes of pre-attentive stimulus discrimination were recorded before and after delivering anodal and cathodal tDCS to the left DLPFC.
  
  
  RESULTS
  MMN amplitudes for all kinds of deviants decreased from pre- to post-tDCS measurement. For duration and intensity deviants, this pre-post reduction was stronger after anodal tDCS, as compared to the decrease after sham stimulation. No such modulation was found for the MMN to frequency deviants. Neither the novelty-P3 nor the target-P3 was modulated by tDCS.
  
  
  CONCLUSIONS
  The selective MMN decrease after anodal (excitatory) stimulation of the left DLPFC suggests that this region either inhibits the processing of specific auditory changes or modulates the habituation of the MMN to certain kinds of deviances.
  
  
  CONCLUSIONS
  Our finding that left frontal anodal tDCS reduces the MMN to duration and intensity deviants further highlights the contribution of frontal brain regions to MMN generation and extends previous reports of reduced MMNs to frequency deviants after right frontal anodal tDCS.
authors.affiliation: Department of Psychology, Experimental Neuropsychology Unit, Saarland University, 66041 Saarbrücken, Germany. Electronic address: m.weigl@mx.uni-saarland.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Weigl
authors.affiliation: Department of Psychology, Experimental Neuropsychology Unit, Saarland University, 66041 Saarbrücken, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Mecklinger
authors.affiliation: Department of Psychology, Experimental Neuropsychology Unit, Saarland University, 66041 Saarbrücken, Germany; Department of Forensic Psychiatry, University Psychiatric Clinics, Wilhelm Klein-Str. 27, 4012 Basel, Switzerland.
authors.forename: Timm
authors.initials: T
authors.lastname: Rosburg
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D017397:Prefrontal Cortex / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation; D055815:Young Adult
keywords: Mismatch negativity (MMN); Neuroplasticity; P300; Prefrontal cortex; Transcranial direct current stimulation (tDCS)