title: Paradoxical Expectation: Oscillatory Brain Activity Reveals Social Interaction Impairment in Schizophrenia.
abstract: BACKGROUND
  People with schizophrenia show social impairments that are related to functional outcomes. We tested the hypothesis that social interaction impairments in people with schizophrenia are related to alterations in the predictions of others' behavior and explored their underlying neurobiological mechanisms.
  
  
  METHODS
  Electroencephalography was performed in 20 patients with schizophrenia and 25 well-matched control subjects. Participants played as proposers in the repeated version of the Ultimatum Game believing that they were playing with another human or with a computer. The power of oscillatory brain activity was obtained by means of the wavelet transform. We performed a trial-by-trial correlation between the oscillatory activity and the risk of the offer.
  
  
  RESULTS
  Control subjects adapted their offers when playing with computers and tended to maintain their offers when playing with humans, as such revealing learning and bargaining strategies, respectively. People with schizophrenia presented the opposite pattern of behavior in both games. During the anticipation of others' responses, the power of alpha oscillations correlated with the risk of the offers made, in a different way in both games. Patients with schizophrenia presented a greater correlation in computer games than in human games; control subjects showed the opposite pattern. The alpha activity correlated with positive symptoms.
  
  
  CONCLUSIONS
  Our results reveal an alteration in social interaction in patients with schizophrenia that is related to oscillatory brain activity, suggesting maladjustment of expectation when patients face social and nonsocial agents. This alteration is related to psychotic symptoms and could guide further therapies for improving social functioning in patients with schizophrenia.
authors: Centro de Investigación en Complejidad Social, Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile; Laboratorio de Neurociencias Cognitivas, Departamento de Psiquiatría, Facultad de Medicina, and Interdisciplinary Center for Neuroscience, Santiago, Chile. Electronic address: pbilleke@udd.cl.
authors: Pablo
authors: P
authors: Billeke
authors: Instituto Psiquiátrico Dr. Horwitz Barak, Servicio de Salud Metropolitano Norte, Santiago, Chile.
authors: Alejandra
authors: A
authors: Armijo
authors: Instituto Psiquiátrico Dr. Horwitz Barak, Servicio de Salud Metropolitano Norte, Santiago, Chile.
authors: Daniel
authors: D
authors: Castillo
authors: Instituto Psiquiátrico Dr. Horwitz Barak, Servicio de Salud Metropolitano Norte, Santiago, Chile.
authors: Tamara
authors: T
authors: López
authors: Centro de Investigación en Complejidad Social, Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile; Laboratorio de Neurociencias Cognitivas, Departamento de Psiquiatría, Facultad de Medicina, and Interdisciplinary Center for Neuroscience, Santiago, Chile.
authors: Francisco
authors: F
authors: Zamorano
authors: Departamento de Psicología, Facultad de Ciencias Sociales, Pontificia Universidad Católica de Chile.
authors: Diego
authors: D
authors: Cosmelli
authors: Laboratorio de Neurociencias Cognitivas, Departamento de Psiquiatría, Facultad de Medicina, and Interdisciplinary Center for Neuroscience, Santiago, Chile.
authors: Francisco
authors: F
authors: Aboitiz
mesh_terms: D000293:Adolescent; D000328:Adult; D000513:Alpha Rhythm; D001611:Beta Rhythm; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D005716:Game Theory; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D055815:Young Adult
keywords: Alpha oscillation; EEG; Game theory; Schizophrenia; Social cognition; Theory of mind; Ultimatum game