title: Using binocular rivalry to tag foreground sounds: Towards an objective visual measure for auditory multistability.
abstract: In binocular rivalry, paradigms have been proposed for unobtrusive moment-by-moment readout of observers' perceptual experience ("no-report paradigms"). Here, we take a first step to extend this concept to auditory multistability. Observers continuously reported which of two concurrent tone sequences they perceived in the foreground: high-pitch (1008 Hz) or low-pitch (400 Hz) tones. Interstimulus intervals were either fixed per sequence (Experiments 1 and 2) or random with tones alternating (Experiment 3). A horizontally drifting grating was presented to each eye; to induce binocular rivalry, gratings had distinct colors and motion directions. To associate each grating with one tone sequence, a pattern on the grating jumped vertically whenever the respective tone occurred. We found that the direction of the optokinetic nystagmus (OKN)-induced by the visually dominant grating-could be used to decode the tone (high/low) that was perceived in the foreground well above chance. This OKN-based readout improved after observers had gained experience with the auditory task (Experiments 1 and 2) and for simpler auditory tasks (Experiment 3). We found no evidence that the visual stimulus affected auditory multistability. Although decoding performance is still far from perfect, our paradigm may eventually provide a continuous estimate of the currently dominant percept in auditory multistability.
authors.affiliation: Chemnitz University of Technology, Institute of Physics, Physics of Cognition Group, Chemnitz, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Einhäuser
authors.affiliation: Chemnitz University of Technology, Institute of Physics, Cognitive Systems Lab, Chemnitz, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Thomassen
authors.affiliation: Chemnitz University of Technology, Institute of Physics, Cognitive Systems Lab, Chemnitz, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Bendixen
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D013017:Sound Localization / Q000502:physiology*; D015357:Vision Disparity / Q000502:physiology*; D015348:Vision, Binocular / Q000502:physiology*; D055815:Young Adult