title: The Merit of Synesthesia for Consciousness Research.
abstract: Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We first review the research on the dynamic and rapidly growing field of the studies of synesthesia. We particularly draw attention to the role of semantics in synesthesia, which is important for establishing synesthetic associations in the brain. We then propose that the interplay between semantics and sensory input in synesthesia can be helpful for the study of the neural correlates of consciousness, especially when making use of ambiguous stimuli for inducing synesthesia. Finally, synesthesia-related alterations of brain networks and functional connectivity can be of merit for the study of consciousness.
authors.affiliation: Department of Neurophysiology, Max Planck Institute for Brain Research Frankfurt am Main, Germany ; Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society Frankfurt am Main, Germany ; Centre for Cognition, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Nijmegen, Netherlands.
authors.forename: Tessa M
authors.initials: TM
authors.lastname: van Leeuwen
authors.affiliation: Department of Neurophysiology, Max Planck Institute for Brain Research Frankfurt am Main, Germany ; Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society Frankfurt am Main, Germany ; Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University Frankfurt am Main, Germany.
authors.forename: Wolf
authors.initials: W
authors.lastname: Singer
authors.affiliation: Department of Neurophysiology, Max Planck Institute for Brain Research Frankfurt am Main, Germany ; Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society Frankfurt am Main, Germany ; Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University Frankfurt am Main, Germany ; Department of Psychology, University of Zagreb Zagreb, Croatia.
authors.forename: Danko
authors.initials: D
authors.lastname: Nikolić
keywords: NCC; ambiguous stimuli; consciousness; effective connectivity; parietal cortex; qualia; semantics; synesthesia