title: Decoding of task-relevant and task-irrelevant intracranial EEG representations.
abstract: Natural stimuli consist of multiple properties. However, not all of these properties are equally relevant in a given situation. In this study, we applied multivariate classification algorithms to intracranial electroencephalography data of human epilepsy patients performing an auditory Stroop task. This allowed us to identify neuronal representations of task-relevant and irrelevant pitch and semantic information of spoken words in a subset of patients. When properties were relevant, representations could be detected after about 350ms after stimulus onset. When irrelevant, the association with gamma power differed for these properties. Patients with more reliable representations of irrelevant pitch showed increased gamma band activity (35-64Hz), suggesting that attentional resources allow an increase in gamma power in some but not all patients. This effect was not observed for irrelevant semantics, possibly because the more automatic processing of this property allowed for less variation in free resources. Processing of different properties of the same stimulus seems therefore to be dependent on the characteristics of the property.
authors.affiliation: Radboud University, Donders Institute for Brain, Cognition and Behaviour, 6500 HE, Nijmegen, The Netherlands. Electronic address: m.vandenieuwenhuijzen@donders.ru.nl.
authors.forename: M E
authors.initials: ME
authors.lastname: van de Nieuwenhuijzen
authors.affiliation: Department of Neuropsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, D-44801 Bochum, Germany; German Center for Neurodegenerative Diseases, D-53175 Bonn, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Axmacher
authors.affiliation: Department of Epileptology, University of Bonn, D-53105 Bonn, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Fell
authors.affiliation: Department of Epileptology, University of Bonn, D-53105 Bonn, Germany.
authors.forename: C R
authors.initials: CR
authors.lastname: Oehrn
authors.affiliation: Radboud University, Donders Institute for Brain, Cognition and Behaviour, 6500 HE, Nijmegen, The Netherlands.
authors.forename: O
authors.initials: O
authors.lastname: Jensen
authors.affiliation: Radboud University, Donders Institute for Brain, Cognition and Behaviour, 6500 HE, Nijmegen, The Netherlands.
authors.forename: M A J
authors.initials: MAJ
authors.lastname: van Gerven
mesh_terms: D000328:Adult; D001288:Attention; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000503:physiopathology*; D005260:Female; D006040:Goals; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology*; D012680:Sensitivity and Specificity; D013067:Speech Perception; D013647:Task Performance and Analysis
keywords: Auditory perception; Intracranial EEG; Multivariate analysis; Task-relevance