RT info:eu-repo/semantics/article T1 Decreased entropy modulation of EEG response to novelty and relevance in schizophrenia during a P300 task A1 Bachiller, Alejandro A1 Lubeiro, Alba A1 Díez, Álvaro A1 Suazo, Vanessa A1 Domínguez, Cristina A1 Blanco, José A. A1 Ayuso, Marta A1 Hornero, Roberto A1 Poza, Jesús A1 Molina, Vicente AB The analysis of the interaction between novelty and relevance may be of interest to test the aberrant salience hypothesis of schizophrenia (SCH). In comparison with other neuroimaging techniques, such as functional magnetic resonance imaging, electroencephalography (EEG) provides high temporal resolution. Therefore, EEG is useful to analyze transient dynamics in neural activity, even in the range of milliseconds. In this study, EEG activity from 31 patients with SCH and 38 controls was analyzed using Shannon spectral entropy (SE) and median frequency (MF). The aim of the study was to quantify differences between distractor (i.e., novelty) and target (i.e., novelty and relevance) tones in an auditory oddball paradigm. Healthy controls displayed a larger SE decrease in response to target stimulus than in response to distractor tones. SE decrease was accompanied by a significant and widespread reduction of MF (i.e., a significant slowing of EEG activity). In comparison with controls, patients showed a significant reduction of changes in SE in response to both target and distractor tones. These differences were also observed in patients that only received a minimal treatment prior to EEG recording. Furthermore, significant changes in SE were inversely correlated to positive and total symptoms severity for SCH patients. Our findings support the notion that SCH is associated with a reduced response to both novelty and relevance during an auditory P300 task. SN 0940-1334 YR 2014 FD 2014 LK https://uvadoc.uva.es/handle/10324/66455 UL https://uvadoc.uva.es/handle/10324/66455 LA spa NO European Archives of Psychiatry and Clinical Neuroscience 265(6): 525-35 DS UVaDOC RD 01-nov-2024