title: Prestimulus Network Integration of Auditory Cortex Predisposes Near-Threshold Perception Independently of Local Excitability.
abstract: An ever-increasing number of studies are pointing to the importance of network properties of the brain for understanding behavior such as conscious perception. However, with regards to the influence of prestimulus brain states on perception, this network perspective has rarely been taken. Our recent framework predicts that brain regions crucial for a conscious percept are coupled prior to stimulus arrival, forming pre-established pathways of information flow and influencing perceptual awareness. Using magnetoencephalography (MEG) and graph theoretical measures, we investigated auditory conscious perception in a near-threshold (NT) task and found strong support for this framework. Relevant auditory regions showed an increased prestimulus interhemispheric connectivity. The left auditory cortex was characterized by a hub-like behavior and an enhanced integration into the brain functional network prior to perceptual awareness. Right auditory regions were decoupled from non-auditory regions, presumably forming an integrated information processing unit with the left auditory cortex. In addition, we show for the first time for the auditory modality that local excitability, measured by decreased alpha power in the auditory cortex, increases prior to conscious percepts. Importantly, we were able to show that connectivity states seem to be largely independent from local excitability states in the context of a NT paradigm.
authors.affiliation: Department of Psychology, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Leske
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy.
authors.forename: Philipp
authors.initials: P
authors.lastname: Ruhnau
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy.
authors.forename: Julia
authors.initials: J
authors.lastname: Frey
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy.
authors.forename: Chrysa
authors.initials: C
authors.lastname: Lithari
authors.affiliation: Department of Neurology, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany.
authors.forename: Nadia
authors.initials: N
authors.lastname: Müller
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hartmann
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy.
authors.forename: Nathan
authors.initials: N
authors.lastname: Weisz
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000513:Alpha Rhythm; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D003243:Consciousness / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D005260:Female; D007839:Functional Laterality; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D012684:Sensory Thresholds / Q000502:physiology*; D055815:Young Adult
keywords: MEG; auditory consciousness; functional connectivity; graph theory; ongoing oscillations