title: Noise power associated with decreased task-induced variability of brain electrical activity in schizophrenia.
abstract: In schizophrenia, both increased baseline metabolic and electroencephalographic (EEG) activities as well as decreased task-related modulation of neural dynamics have been reported. Noise power (NP) can measure the background EEG activity during task performance, and Shannon entropy (SE) is useful for quantifying the global modulation of EEG activity with a high temporal resolution. In this study, we have assessed the possible relationship between increased NP in theta and gamma bands and decreased SE modulation in 24 patients with schizophrenia and 26 controls over the parietal and central regions during a P300 task. SE modulation was calculated as the change from baseline to the active epoch (i.e., 150-550 ms following the target stimulus onset). Patients with schizophrenia displayed statistically significant higher NP values and lower SE modulation than healthy controls. We found a significant association between gamma NP and SE in all of the participants. Specifically, a NP increase in the gamma band was followed by a decrease in SE change. These results support the notion that an excess of gamma activity, unlocked to the task being performed, is accompanied by a decreased modulation of EEG activity in schizophrenia.
authors.affiliation: Department of Psychiatry, School of Medicine, University of Valladolid, Avenida de Ramón y Cajal, 7, 48005, Valladolid, Spain. vmolina@med.uva.es.|Neuroscience Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain. vmolina@med.uva.es.
authors.forename: Vicente
authors.initials: V
authors.lastname: Molina
authors.affiliation: Biomedical Engineering Group, Department T.S.C.I.T., E.T.S. Ingenieros de Telecomunicación, University of Valladolid, Valladolid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Bachiller
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: Biomedical Engineering Group, Department T.S.C.I.T., E.T.S. Ingenieros de Telecomunicación, University of Valladolid, Valladolid, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Lubeiro
authors.affiliation: Neuroscience Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain.|Biomedical Engineering Group, Department T.S.C.I.T., E.T.S. Ingenieros de Telecomunicación, University of Valladolid, Valladolid, Spain.|Instituto de Investigación en Matemáticas (IMUVA), University of Valladolid, Valladolid, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Poza
authors.affiliation: Neuroscience Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain.|Biomedical Engineering Group, Department T.S.C.I.T., E.T.S. Ingenieros de Telecomunicación, 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
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001921:Brain / Q000187:drug effects / Q000503:physiopathology*; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D016022:Case-Control Studies; D004569:Electroencephalography; D019277:Entropy; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000188:drug therapy / Q000473:pathology*; D013057:Spectrum Analysis; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents
keywords: Gamma; Inhibition; Noise power; Schizophrenia; Shannon entropy; Theta