title: The causal role of the dorsolateral prefrontal cortex in the modification of attentional bias: evidence from transcranial direct current stimulation.
abstract: BACKGROUND
  A pattern of attentional bias for threatening information is thought to be involved in the etiology of anxiety. Consistent with this idea, cognitive training techniques directly targeting such patterns of biased attention have been shown to reduce symptoms of anxiety. Research seeking to establish the neurologic underpinnings of change in the attentional bias for threat have implicated, but not confirmed, the role of lateral prefrontal regions.
  
  
  METHODS
  The current study sought to confirm experimentally the causal role of lateral prefrontal areas in the modification of attentional bias by delivering targeted cortical stimulation during attention bias modification training to assess the consequent effects on attentional bias change. While completing either an "attend threat" or "avoid threat" attention bias modification task, 77 volunteers (17-22 per group) received either active transcranial direct current stimulation of the left dorsolateral prefrontal cortex or a sham stimulation control condition.
  
  
  RESULTS
  Participants receiving active stimulation showed greater evidence of attentional bias acquisition in the targeted direction (toward or away from threat) compared with participants in the sham stimulation condition.
  
  
  CONCLUSIONS
  Our findings provide the first experimental evidence that increasing activity in the dorsolateral prefrontal cortex leads to greater evidence of attention bias modification. This evidence confirms the role of these areas in facilitating change in the allocation of attention to threat. We believe this study provides a critical step in the translation of neuroimaging findings to novel neuromodulatory interventions capable of enhancing the treatment of emotional pathology.
authors.affiliation: School of Psychology, University of Western Australia, Crawley, Western Australia, Australia. Electronic address: patrick.clarke@uwa.edu.au.
authors.forename: Patrick J F
authors.initials: PJ
authors.lastname: Clarke
authors.affiliation: Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford; P1vital Ltd, Wallingford, Oxfordshire, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Browning
authors.affiliation: School of Psychology, University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Geoff
authors.initials: G
authors.lastname: Hammond
authors.affiliation: School of Psychology, University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Lies
authors.initials: L
authors.lastname: Notebaert
authors.affiliation: School of Psychology, University of Western Australia, Crawley, Western Australia, Australia; School of Psychology, Babes-Bolyai University, Cluj-Napoca, Romania.
authors.forename: Colin
authors.initials: C
authors.lastname: MacLeod
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D015982:Bias; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D065908:Transcranial Direct Current Stimulation; D055815:Young Adult
keywords: Anxiety; attentional bias; cognitive bias; cognitive bias modification; cognitive training; tDCS