title: Prestimulus oscillatory alpha power and connectivity patterns predispose perceptual integration of an audio and a tactile stimulus.
abstract: To efficiently perceive and respond to the external environment, our brain has to perceptually integrate or segregate stimuli of different modalities. The temporal relationship between the different sensory modalities is therefore essential for the formation of different multisensory percepts. In this magnetoencephalography study, we created a paradigm where an audio and a tactile stimulus were presented by an ambiguous temporal relationship so that perception of physically identical audiotactile stimuli could vary between integrated (emanating from the same source) and segregated. This bistable paradigm allowed us to compare identical bimodal stimuli that elicited different percepts, providing a possibility to directly infer multisensory interaction effects. Local differences in alpha power over bilateral inferior parietal lobules (IPLs) and superior parietal lobules (SPLs) preceded integrated versus segregated percepts of the two stimuli (audio and tactile). Furthermore, differences in long-range cortical functional connectivity seeded in rIPL (region of maximum difference) revealed differential patterns that predisposed integrated or segregated percepts encompassing secondary areas of all different modalities and prefrontal cortex. We showed that the prestimulus brain states predispose the perception of the audiotactile stimulus both in a global and a local manner. Our findings are in line with a recent consistent body of findings on the importance of prestimulus brain states for perception of an upcoming stimulus. This new perspective on how stimuli originating from different modalities are integrated suggests a non-modality specific network predisposing multisensory perception.
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Trento, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Leonardelli
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Trento, Italy.|MEG Center, University of Tübingen, Tübingen, Germany.|Werner Reichardt Centre for Integrative Neuroscience(CIN), University of Tübingen, Tübingen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Braun
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Trento, Italy.
authors.forename: Nathan
authors.initials: N
authors.lastname: Weisz
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Trento, Italy.
authors.forename: Chrysa
authors.initials: C
authors.lastname: Lithari
authors.affiliation: Department of Neurology, Emory University, Atlanta, Georgia.
authors.forename: Valeria
authors.initials: V
authors.lastname: Occelli
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Trento, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Zampini
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001307:Auditory Perception; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D010812:Physical Stimulation; D012815:Signal Processing, Computer-Assisted; D055698:Touch Perception
keywords: audiotactile; functional connectivity; magnetoencephalography; multisensory interactions; prestimulus