title: Meta-analysis of face processing event-related potentials in schizophrenia.
abstract: BACKGROUND
  Schizophrenia is associated with impaired face processing. N170 and N250 are two event-related potentials that have been studied in relation to face processing in schizophrenia, but the results have been mixed. The aim of this article was to conduct a meta-analysis of N170 and N250 in schizophrenia to evaluate trends and resolve the inconsistencies.
  
  
  METHODS
  Twenty-one studies of N170 (n = 438 schizophrenia patients, n = 418 control subjects) and six studies of N250 (n = 149 schizophrenia patients, n = 151 control subjects) were evaluated. Hedges' g was calculated for each study, and the overall weighted mean effect size (ES) was calculated for N170 and N250. Homogeneity of the ES distributions, potential publication bias, and impact of potential moderators were also assessed.
  
  
  RESULTS
  The amplitude of both N170 and N250 to face stimuli was smaller in patients than control subjects (N170 ES = .64; N250 ES = .49; ps < .001). The distributions of the ES were homogeneous (ps > .90), and there was no indication of a publication bias. We found no significant effect of task requirements regarding judgments of the face stimuli. Moreover, we found no significant difference between the ES for N170 and N250.
  
  
  CONCLUSIONS
  Though findings of individual studies have been mixed, the results of the meta-analysis strongly support disruption of N170 and N250 in schizophrenia. The comparable effect sizes across the two waveforms suggest that the well-established behavioral deficit in face emotion processing is mirrored in an underlying neural impairment for processing faces.
authors.affiliation: UCLA Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California. Electronic address: amccleery@mednet.ucla.edu.
authors.forename: Amanda
authors.initials: A
authors.lastname: McCleery
authors.affiliation: UCLA Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California.
authors.forename: Junghee
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California.
authors.forename: Aditi
authors.initials: A
authors.lastname: Joshi
authors.affiliation: UCLA Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Wynn
authors.affiliation: UCLA Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California.
authors.forename: Gerhard S
authors.initials: GS
authors.lastname: Hellemann
authors.affiliation: UCLA Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Green
mesh_terms: D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D004644:Emotions; D005071:Evoked Potentials; D005149:Facial Expression; D006801:Humans; D008279:Magnetic Resonance Imaging; D010364:Pattern Recognition, Visual / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology
keywords: ERP; Emotion identification; Face processing; N170; N250; Schizophrenia