title: The role of the occipital face area in holistic processing involved in face detection and discrimination: A tDCS study.
abstract: OBJECTIVE
  The aim of this study was to examine the role of occipital face area (OFA) in mediating observers' tendency to perceive faces as "wholes" (holistic processing) both when detecting and discriminating faces. To investigate this issue, we modulated OFA activity using transcranial direct current stimulation (tDCS).
  
  
  METHODS
  In Experiment 1, participants performed a face detection task (the Mooney faces task) and a face discrimination task (the Composite faces task), which both assess holistic face processing. In Experiment 2, participants were asked to detect both Mooney faces and Mooney objects, to test face selectivity of OFA. In each experimental session, the tasks were presented once before (pre) and once after (post) administration of 20 min of excitability increasing anodal tDCS (real) and sham stimulation over the putative OFA.
  
  
  RESULTS
  Compared with sham stimulation, we found that real anodal tDCS interfered with both Mooney faces and objects detection, whereas it had no effect on holistic processing involved in face discrimination, as measured by the Composite faces task.
  
  
  CONCLUSIONS
  Our results suggest that OFA is causally implicated in facial detection at least in degraded conditions (i.e., when the "face" signal needs to be extracted from a noisy background). In turn, our data do not implicate OFA in holistic processing in face discrimination. Finally, our data suggest a possible role of OFA in categorization of other nonface stimuli, a conclusion that must be taken with caution, as stimulation over OFA may affect object-selective adjacent regions.
authors.affiliation: Brain Connectivity Center, National Neurological Institute C. Mondino.
authors.forename: Chiara
authors.initials: C
authors.lastname: Renzi
authors.affiliation: Brain Connectivity Center, National Neurological Institute C. Mondino.
authors.forename: Chiara
authors.initials: C
authors.lastname: Ferrari
authors.affiliation: Department of Psychology, University of Milano-Bicocca.
authors.forename: Susanna
authors.initials: S
authors.lastname: Schiavi
authors.affiliation: Department of Psychology, University of Milano-Bicocca.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pisoni
authors.affiliation: Department of Psychology, University of Milano-Bicocca.
authors.forename: Costanza
authors.initials: C
authors.lastname: Papagno
authors.affiliation: Brain Connectivity Center, National Neurological Institute C. Mondino.
authors.forename: Tomaso
authors.initials: T
authors.lastname: Vecchi
authors.affiliation: Department of Clinical Neurophysiology, Georg-August University.
authors.forename: Andrea
authors.initials: A
authors.lastname: Antal
authors.affiliation: Department of Psychology, University of Milano-Bicocca, Brain Connectivity Center, National Neurological Institute C. Mondino.
authors.forename: Zaira
authors.initials: Z
authors.lastname: Cattaneo
mesh_terms: D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology*; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D009778:Occipital Lobe / Q000502:physiology*; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult