Blind spot and visual field anisotropy detection with flicker pupil perimetry across brightness and task variations

Portengen, B. L., Roelofzen, C., Porro, G. L., Imhof, S. M., Fracasso, A. and Naber, M. (2021) Blind spot and visual field anisotropy detection with flicker pupil perimetry across brightness and task variations. Vision Research, 178, pp. 79-85. (doi: 10.1016/j.visres.2020.10.005) (PMID:33161146)

Abstract

The pupil can be used as an objective measure for testing sensitivities across the visual field (pupil perimetry; PP). The recently developed gaze-contingent flicker PP (gcFPP) is a promising novel form of PP, with improved sensitivity due to retinotopically stable and repeated flickering stimulations, in a short time span. As a diagnostic tool gcFPP has not yet been benchmarked in healthy individuals. The main aims of the current study were to investigate whether gcFPP has the sensitivity to detect the blind spot, and upper versus lower visual field differences that were found before in previous studies. An additional aim was to test for the effects of attentional requirements and background luminance. A total of thirty individuals were tested with gcFPP across two separate experiments. The results showed that pupil oscillation amplitudes were smaller for stimuli presented inside as compared to outside the blind spot. Amplitudes also decreased as a function of eccentricity (i.e., distance to fixation) and were larger for upper as compared to lower visual fields. We measured the strongest and most sensitive pupil responses to stimuli presented on dark- and mid-gray backgrounds, and when observers covertly focused their attention to the flickering stimulus. GcFPP thus evokes pupil responses that are sensitive enough to detect local, and global differences in pupil sensitivity. The findings further encourage (1) the use of a gray background to prevent straylight without affecting gcFPPs sensitivity and (2) the use of an attention task to enhance pupil sensitivity.

• Item Type: Articles
• Keywords: Blind spot, perimetry, pupillometry, visual field.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fracasso, Dr Alessio

Creator Roles

Fracasso, A.: Project administration, Writing – review and editing

• Authors: Portengen, B. L., Roelofzen, C., Porro, G. L., Imhof, S. M., Fracasso, A., and Naber, M.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Vision Research
• Publisher: Elsevier
• ISSN: 0042-6989
• ISSN (Online): 1878-5646
• Published Online: 05 November 2020
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Vision Research 178: 79-85
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
303685		Stable perception of external stimuli over time: oculo-motor and visual processing mechanisms	Alessio Fracasso	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/S006605/1	NP - Centre for Cognitive Neuroimaging (CCNi)