title: Association between electroencephalographic modulation, psychotic-like experiences and cognitive performance in the general population.
abstract: An association between deficit of electroencephalographic (EEG) modulation during an odd-ball task and psychotic symptoms has been described in clinical samples, in agreement with the proposed role for altered salience in psychosis. To discard the possible influence of medication, the relationship between psychotic-like experiences and EEG modulation in the general population was explored.
  
  
  
  EEG and psychotic-like experiences were assessed in 194 healthy subjects during a P300 paradigm. EEG modulation was assessed as changes from pre-stimulus to response windows in spectral entropy (SE, a measurement of signal irregularity), median frequency (MF, a quantifier of the frequency distribution of oscillatory activity) and theta, alpha, beta-1, beta-2 and gamma relative power (RP, a summary of the distribution of spectral components).
  
  
  
  A significant widespread decrease in SE and MF from baseline to response was found, with a significant increase in RP for theta and a decrease for higher frequency bands, supporting an increase in EEG regularity and a slowing of brain oscillations during the response. Furthermore, a significant association was found between SE modulation and distress of negative psychotic-like experiences, as well as between verbal memory and RP modulation for beta-1. Performance in verbal fluency was associated with the increase in theta RP during the response.
  
  
  
  EEG irregularity of healthy subjects decreased at the expense of a larger contribution of theta RP and a decreased contribution of fast frequency bands. Subjects with smaller modulation showed poorer cognitive scores and greater distress of negative psychotic-like experiences.
authors.affiliation: Biomedical Engineering Group, Department, University of Valladolid, Valladolid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Gomez-Pilar
authors.affiliation: Psychiatry Service, University Hospital of Palencia, Palencia, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Martín-Santiago
authors.affiliation: Neuroscience Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Suazo
authors.affiliation: Neuroscience Department, University of the Basque Country, Leioa, Spain.|Psychiatry Service, University Hospital of Alava, Vitoria, Spain.
authors.forename: Sonia Ruiz
authors.initials: SR
authors.lastname: de Azua
authors.affiliation: Psychiatry Service, University Hospital of Alava, Vitoria, Spain.
authors.forename: Mahmoud Karim
authors.initials: MK
authors.lastname: Haidar
authors.affiliation: Psychiatry Service, University Hospital of Palencia, Palencia, Spain.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gallardo
authors.affiliation: Biomedical Engineering Group, Department, University of Valladolid, Valladolid, Spain.|Neuroscience Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain.|Instituto de Investigación en Matemáticas (IMUVA), University of Valladolid, Valladolid, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Poza
authors.affiliation: Biomedical Engineering Group, Department, University of Valladolid, Valladolid, Spain.|Instituto de Investigación en Matemáticas (IMUVA), University of Valladolid, Valladolid, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Hornero
authors.affiliation: Neuroscience Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain.|Psychiatry Department, School of Medicine, University of Valladolid, Valladolid, Spain.|Psychiatry Service, University Hospital of Valladolid, Valladolid, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Molina
keywords: Auditory oddball; Electroencephalography (EEG); Healthy volunteers; P300; Psychotic disorders