title: Improved estimates for the role of grey matter volume and GABA in bistable perception.
abstract: Across a century or more, ambiguous stimuli have been studied scientifically because they provide a method for studying the internal mechanisms of the brain while ensuring an unchanging external stimulus. In recent years, several studies have reported correlations between perceptual dynamics during bistable perception and particular brain characteristics such as the grey matter volume of areas in the superior parietal lobule (SPL) and the relative GABA concentration in the occipital lobe. Here, we attempt to replicate previous results using similar paradigms to those used in the studies first reporting the correlations. Using the original findings as priors for Bayesian analyses, we found strong support for the correlation between structure-from-motion percept duration and anterior SPL grey matter volume. Correlations between percept duration and other parietal areas as well as occipital GABA, however, were not directly replicated or appeared less strong than previous studies suggested. Inspection of the posterior distributions (current "best guess" based on new data given old data as prior) revealed that several original findings may reflect true relationships although no direct evidence was found in support of them in the current sample. Additionally, we found that multiple regression models based on grey matter volume at 2-3 parietal locations (but not including GABA) were the best predictors of percept duration, explaining approximately 35% of the inter-individual variance. Taken together, our results provide new estimates of correlation strengths, generally increasing confidence in the role of the aSPL while decreasing confidence in some of the other relationships.
authors.affiliation: Cognitive Neuroscience Research Unit, CFIN, Aarhus University, Aarhus, Denmark; Hammel Neurorehabilitation and Research Centre, Aarhus University Hospital, Hammel, Denmark; Institute of Cognitive Neuroscience, University College London, London, United Kingdom. Electronic address: krissand@rm.dk.
authors.forename: Kristian
authors.initials: K
authors.lastname: Sandberg
authors.affiliation: Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, Aarhus, Denmark.
authors.forename: Jakob Udby
authors.initials: JU
authors.lastname: Blicher
authors.affiliation: Cognitive Neuroscience Research Unit, CFIN, Aarhus University, Aarhus, Denmark; Consciousness Lab, Institute of Psychology, Jagiellonian University, Krakow, Poland.
authors.forename: Simon Hviid
authors.initials: SH
authors.lastname: Del Pin
authors.affiliation: Cognitive Neuroscience Research Unit, CFIN, Aarhus University, Aarhus, Denmark; NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Lau Møller
authors.initials: LM
authors.lastname: Andersen
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London, United Kingdom.
authors.forename: Geraint
authors.initials: G
authors.lastname: Rees
authors.affiliation: School of Psychology, Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom; Department of Neuroinformatics, Araya Brain Imaging, Tokyo, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Kanai
mesh_terms: D000328:Adult; D001499:Bayes Theorem; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D066128:Gray Matter / Q000000981:diagnostic imaging* / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D005680:gamma-Aminobutyric Acid
keywords: Bistable perception; Gamma aminobutyric acid (GABA); Grey matter volume; Magnetic resonance spectroscopy; Structure-from-motion