title: Symbolic magnitude modulates perceptual strength in binocular rivalry.
abstract: Basic aspects of magnitude (such as luminance contrast) are directly represented by sensory representations in early visual areas. However, it is unclear how symbolic magnitudes (such as Arabic numerals) are represented in the brain. Here we show that symbolic magnitude affects binocular rivalry: perceptual dominance of numbers and objects of known size increases with their magnitude. Importantly, variations in symbolic magnitude acted like variations in luminance contrast: we found that an increase in numerical magnitude of adding one lead to an equivalent increase in perceptual dominance as a contrast increment of 0.32%. Our results support the claim that magnitude is extracted automatically, since the increase in perceptual dominance came about in the absence of a magnitude-related task. Our findings show that symbolic, acculturated knowledge about magnitude interacts with visual perception and affects perception in a manner similar to lower-level aspects of magnitude such as luminance contrast.
authors.affiliation: Experimental Psychology, Department of Psychology, Faculty of Social Sciences & Helmholtz Institute, Utrecht University, Heidelberglaan 2, 3584 CS, The Netherlands. c.l.e.paffen@uu.nl
authors.forename: Chris L E
authors.initials: CL
authors.lastname: Paffen
authors.forename: Sarah
authors.initials: S
authors.lastname: Plukaard
authors.forename: Ryota
authors.initials: R
authors.lastname: Kanai
mesh_terms: D003657:Decision Making / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology; D023882:Dominance, Ocular / Q000502:physiology; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D012858:Size Perception / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult