Orientation-selective adaptation to illusory contours in human visual cortex.

Full Abstract

Humans can perceive illusory or subjective contours in the absence of any real physical boundaries. We used an adaptation protocol to look for orientation-selective neural responses to illusory contours defined by phase-shifted abutting line gratings in the human visual cortex. We measured functional magnetic resonance imaging (fMRI) responses to illusory-contour test stimuli after adapting to an illusory-contour adapter stimulus that was oriented parallel or orthogonal to the test stimulus. We found orientation-selective adaptation to illusory contours in early (V1 and V2) and higher-tier visual areas (V3, hV4, VO1, V3A/B, V7, LO1, and LO2). That is, fMRI responses were smaller for test stimuli parallel to the adapter than for test stimuli orthogonal to the adapter. In two control experiments using spatially jittered and phase-randomized stimuli, we demonstrated that this adaptation was not just in response to differences in the distribution of spectral power in the stimuli. Orientation-selective adaptation to illusory contours increased from early to higher-tier visual areas. Thus, both early and higher-tier visual areas contain neurons selective for the orientation of this type of illusory contour.

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Author information

Author/s: Montaser-Kouhsari, Leila (L); Landy, Michael S (MS); Heeger, David J (DJ); Larsson, Jonas (J);

Affiliation: Department of Psychology, New York University, New York, New York 10003, USA. lmk306(-atsign-)nyu.edu

Grants: EY16165 (Agency:NEI NIH HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't

Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci), published in United States. (Language: eng)

Reference: 2007-Feb; vol 27 (issue 9) : pp 2186-95

Dates: Created 2007/03/01; Completed 2007/03/19; Revised 2007/11/14;

PMID: 17329415, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

Comments and Corrections

CommentIn: J Neurosci. 2007 May 16;27(20):5269-70. (PMID: 17507549)

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MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Magnetic Resonance Imaging
Male
Middle Aged
Optical Illusions - physiology
Orientation - physiology
Visual Cortex - physiology

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