An adaptable metric shapes perceptual space

How do we derive a sense of the separation of points in the world within a space-variant visual system? Visual directions are thought to be coded directly by a process referred to as local sign, in which a neuron acts as a labeled line for the perceived direction associated with its activation. The...

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Main Authors: Hisakata, Rumi, Nishida, Shin'ya, Johnston, Alan
Format: Article
Language:English
Published: Elsevier (Cell Press) 2016
Online Access:https://eprints.nottingham.ac.uk/34298/
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author Hisakata, Rumi
Nishida, Shin'ya
Johnston, Alan
author_facet Hisakata, Rumi
Nishida, Shin'ya
Johnston, Alan
author_sort Hisakata, Rumi
building Nottingham Research Data Repository
collection Online Access
description How do we derive a sense of the separation of points in the world within a space-variant visual system? Visual directions are thought to be coded directly by a process referred to as local sign, in which a neuron acts as a labeled line for the perceived direction associated with its activation. The separations of visual directions are however not given. Nor are they directly related to the separations of signals on the receptive surface or in the brain which are modified by retinal and cortical magnification, respectively. To represent the separation of directions veridically the corresponding neural signals need to be scaled in some way. We considered this scaling process may be influenced by adaptation. Here we describe a novel adaptation paradigm, which can alter both apparent spatial separation and size. We measured the perceived separation of two dots and the size of geometric figures after adaptation to random dot patterns. We show that adapting to high density texture not only increases the apparent sparseness (average element separation) of a lower density pattern, as expected, but paradoxically, it reduces the apparent separation of dot pairs and induces apparent shrinkage of geometric form. This demonstrates for the first time a contrary linkage between perceived density and perceived extent. Separation and size appear to be expressed relative to a variable spatial metric whose properties, while not directly observable, are revealed by reductions in both apparent size and texture density.
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spelling nottingham-342982017-10-12T20:53:42Z https://eprints.nottingham.ac.uk/34298/ An adaptable metric shapes perceptual space Hisakata, Rumi Nishida, Shin'ya Johnston, Alan How do we derive a sense of the separation of points in the world within a space-variant visual system? Visual directions are thought to be coded directly by a process referred to as local sign, in which a neuron acts as a labeled line for the perceived direction associated with its activation. The separations of visual directions are however not given. Nor are they directly related to the separations of signals on the receptive surface or in the brain which are modified by retinal and cortical magnification, respectively. To represent the separation of directions veridically the corresponding neural signals need to be scaled in some way. We considered this scaling process may be influenced by adaptation. Here we describe a novel adaptation paradigm, which can alter both apparent spatial separation and size. We measured the perceived separation of two dots and the size of geometric figures after adaptation to random dot patterns. We show that adapting to high density texture not only increases the apparent sparseness (average element separation) of a lower density pattern, as expected, but paradoxically, it reduces the apparent separation of dot pairs and induces apparent shrinkage of geometric form. This demonstrates for the first time a contrary linkage between perceived density and perceived extent. Separation and size appear to be expressed relative to a variable spatial metric whose properties, while not directly observable, are revealed by reductions in both apparent size and texture density. Elsevier (Cell Press) 2016-07-25 Article PeerReviewed application/pdf en cc_by https://eprints.nottingham.ac.uk/34298/1/1-s2.0-S0960982216305449-main.pdf Hisakata, Rumi, Nishida, Shin'ya and Johnston, Alan (2016) An adaptable metric shapes perceptual space. Current Biology, 26 (14). pp. 1911-1915. ISSN 1879-0445 http://dx.doi.org/10.1016/j.cub.2016.05.047 doi:10.1016/j.cub.2016.05.047 doi:10.1016/j.cub.2016.05.047
spellingShingle Hisakata, Rumi
Nishida, Shin'ya
Johnston, Alan
An adaptable metric shapes perceptual space
title An adaptable metric shapes perceptual space
title_full An adaptable metric shapes perceptual space
title_fullStr An adaptable metric shapes perceptual space
title_full_unstemmed An adaptable metric shapes perceptual space
title_short An adaptable metric shapes perceptual space
title_sort adaptable metric shapes perceptual space
url https://eprints.nottingham.ac.uk/34298/
https://eprints.nottingham.ac.uk/34298/
https://eprints.nottingham.ac.uk/34298/