Interocular suppression patterns in binocularly abnormal observers using luminance- and contrast-modulated noise stimuli

Chima, Akash S. and Formankiewicz, Monika A. and Waugh, Sarah J. (2016) Interocular suppression patterns in binocularly abnormal observers using luminance- and contrast-modulated noise stimuli. Journal of Vision, 16 (10). p. 20. ISSN 1534-7362

[img]
Preview
Text
Published Version
Available under the following license: Creative Commons Attribution Non-commercial No Derivatives.

Download (2MB) | Preview
Official URL: http://doi.org/10.1167/16.10.20

Abstract

In binocular viewing, images presented to the amblyopic eye are suppressed in the cortex to prevent confusion or diplopia. The present study measures depth and extent of interocular suppression across the central circular 248 visual field in observers with strabismus and microstrabismus. Visual stimuli were concentric rings of alternating polarity, each divided into sectors. Rings were defined by luminance (L), luminance-modulated noise (LM), or contrastmodulated noise (CM). They were viewed binocularly except for the tested ring, which was viewed dichoptically, so that the modulation of one sector presented to the weaker or amblyopic eye was adjusted to perceptually match the surrounding ring presented to the preferred eye. A two alternative forced-choice paradigm combined with a staircase procedure allowed for measurement of the point of subjective equality, or perceptual match. Depth of suppression was calculated as the difference between physical modulations presented to the two eyes at this point. Strabismic participants showed suppression deeper centrally than peripherally, and in one hemifield of the visual field more than the other. Suppression was deeper for L than LM, and CM than LM stimuli. Microstrabismic suppression was weaker than that of strabismics, central for L and LM stimuli, with suppression of CM stimuli being broader, deeper and more in one hemifield. Suppression depth was positively correlated with interocular visual acuity difference and stereoacuity reduction. Clinically, LM stimuli could be used for assessment of deeper amblyopes to assess suppression patterns, while more sensitive detection of mild suppression would be possible using CM stimuli.

Item Type: Journal Article
Keywords: amblyopia, strabismus, microstrabismus, suppression, contrast-modulated
Faculty: Faculty of Science & Technology
Depositing User: Unnamed user with email Sarah.Waugh@anglia.ac.uk
Date Deposited: 16 Sep 2016 07:19
Last Modified: 16 Sep 2016 07:19
URI: http://arro.anglia.ac.uk/id/eprint/700829

Actions (login required)

Edit Item Edit Item