Microsaccadic eye movement orientations are equivocal in the presence of competing stimuli

Eswar Kurni¹, Manish Reddy Yedulla² and PremNandhini Satgunam^1
1Brien Holden Institute of Optometry and Vision Sciences, Hyderabad Eye Research Foundation,
L V Prasad Eye Institute, Hyderabad- 500 034, India
²Department of Engineering Science, Indian Institute of Technology, Hyderabad-502 285, India
Dedicated to Prof Jay M Enoch

Will someone reflexively look towards a primed target or to a non-primed target, when no instructions are given? Knowing this could help design visual function tests without the need for instructions. Simply, a target could be presented for a “priming phase” followed by two targets one of which is the primed target and the other is not. We asked the question to which target will an obsever look. We studied this on normally-sighted adults. Eye movements were tracked using EyeLink1000 Plus eye tracker and microsaccades were analyzed. The targets presented were from LEA symbols that are commonly used in children’s visual acuity chart. Target size (15′, 20′ or 25′) and presentation duration (200, 400 or 600 ms) were randomized. No instructions were given to the participants beyond asking them to look at the computer monitor in experiment I, and instructions were given to specifically look towards the primed target in experiment II. Overall we found that no preference (proportion of microsaccades <50%) was observed either to the primed or to the novel target in either of the experiments. The presence of two competing stimuli abolishes the microsaccde orientation to a target of interest, even with explicit verbal instructions. © Anita Publications. All rights reserved.
Keywords: Microsaccades, Preferential looking, Visual search, Latency, Priming, Eye movements.

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Method: Single- anonymous; Screened for Plagiarism? Yes
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