Flicker-defined form stimuli are minimally affected by centre-surround lateral contrast interactions

Denniss, Jonathan and McKendrick, Allison M. (2016) Flicker-defined form stimuli are minimally affected by centre-surround lateral contrast interactions. Ophthalmic and Physiological Optics . ISSN 1475-1313

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Abstract

Purpose: Flicker-defined form (FDF) stimuli have recently been adopted for visual field testing. A key difference between FDF and traditional perimetric stimuli is that the entire display background contains flickering dots. The purpose of this study was to determine whether the perception of FDF stimuli is influenced by lateral interactions involving regions beyond the stimulus border in young healthy observers.

Methods: Experiment 1 measured the effect of surround size and retinal eccentricity on the detection of the FDF contour. Psychometric functions were collected for surround diameters of 20, 30 and 40°, and with stimuli centered at eccentricities of 0, 10 and 20°. Experiment 2 measured the effect of target-surround temporal phase difference on apparent temporal contrast (flicker strength) of the target for both the FDF stimulus and a solid-field stimulus. Psychometric functions were collected for target-surround phase differences of 0, 45, 90, 135 and 180°.

Results: Our results show a mild surround-suppression effect for FDF stimuli that is independent of surround size. Magnitudes of FDF surround suppression were consistent with the reduced temporal contrast energy of the stimulus compared to solid-field stimuli.

Conclusion: FDF stimuli necessarily have both flickering target and background. Our results suggest that visual field defects outside the target are unlikely to markedly influence the detection and perception of the FDF stimulus. Nevertheless, mild surround suppression of contrast arises for FDF stimuli, hence interactions between the background and the target area may influence FDF results in conditions that alter centre-surround perceptual effects.

Item Type: Article
Additional Information: This is the peer reviewed version of the following article: Denniss J & McKendrick AM. Flicker-defined form stimuli are minimally affected by centre-surround lateral contrast interactions. Ophthalmic Physiol Opt 2016. doi: 10.1111/opo.12268, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/opo.12268/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
Keywords: Centre-surround; Flicker; Flicker-defined form; Lateral interactions; Perimetry; Phantom contour
Schools/Departments: University of Nottingham UK Campus > Faculty of Science > School of Psychology
Identification Number: https://doi.org/10.1111/opo.12268
Depositing User: Denniss, Jonathan
Date Deposited: 14 Jan 2016 15:42
Last Modified: 16 Sep 2016 12:26
URI: http://eprints.nottingham.ac.uk/id/eprint/31254

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