title: Cortical idiosyncrasies predict the perception of object size.
abstract: Perception is subjective. Even basic judgments, like those of visual object size, vary substantially between observers and also across the visual field within the same observer. The way in which the visual system determines the size of objects remains unclear, however. We hypothesize that object size is inferred from neuronal population activity in V1 and predict that idiosyncrasies in cortical functional architecture should therefore explain individual differences in size judgments. Here we show results from novel behavioural methods and functional magnetic resonance imaging (fMRI) demonstrating that biases in size perception are correlated with the spatial tuning of neuronal populations in healthy volunteers. To explain this relationship, we formulate a population read-out model that directly links the spatial distribution of V1 representations to our perceptual experience of visual size. Taken together, our results suggest that the individual perception of simple stimuli is warped by idiosyncrasies in visual cortical organization.
authors.affiliation: Experimental Psychology, University College London, 26 Bedford Way, London WC1H 0AP, UK.|Department of Psychology, Kingston University, Penrhyn Road, Kingston Upon Thames, Surrey, London KT1 2EE, UK.
authors.forename: Christina
authors.initials: C
authors.lastname: Moutsiana
authors.affiliation: Experimental Psychology, University College London, 26 Bedford Way, London WC1H 0AP, UK.|UCL Institute of Cognitive Neuroscience, 17 Queen Square, London WC1N 3AZ, UK.
authors.forename: Benjamin
authors.initials: B
authors.lastname: de Haas
authors.affiliation: Experimental Psychology, University College London, 26 Bedford Way, London WC1H 0AP, UK.
authors.forename: Andriani
authors.initials: A
authors.lastname: Papageorgiou
authors.affiliation: Experimental Psychology, University College London, 26 Bedford Way, London WC1H 0AP, UK.|UCL Institute of Cognitive Neuroscience, 17 Queen Square, London WC1N 3AZ, UK.
authors.forename: Jelle A
authors.initials: JA
authors.lastname: van Dijk
authors.affiliation: Experimental Psychology, University College London, 26 Bedford Way, London WC1H 0AP, UK.|Columbian College of Arts and Sciences, The George Washington University, 2125 G Street NW, Washington 20052, USA.
authors.forename: Annika
authors.initials: A
authors.lastname: Balraj
authors.affiliation: Experimental Psychology, University College London, 26 Bedford Way, London WC1H 0AP, UK.
authors.forename: John A
authors.initials: JA
authors.lastname: Greenwood
authors.affiliation: Experimental Psychology, University College London, 26 Bedford Way, London WC1H 0AP, UK.|UCL Institute of Cognitive Neuroscience, 17 Queen Square, London WC1N 3AZ, UK.
authors.forename: D Samuel
authors.initials: DS
authors.lastname: Schwarzkopf
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012858:Size Perception / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult