PT  - JOURNAL ARTICLE
AU  - Norick R. Bowers
AU  - Josselin Gautier
AU  - Samantha Lin
AU  - Austin Roorda
TI  - Fixational eye movements depend on task and target
AID  - 10.1101/2021.04.14.439841
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.04.14.439841
4099  - http://biorxiv.org/content/early/2021/04/14/2021.04.14.439841.short
4100  - http://biorxiv.org/content/early/2021/04/14/2021.04.14.439841.full
AB  - Human fixational eye movements are so small and precise that they require high-speed, accurate tools to fully reveal their properties and functional roles. Where the fixated image lands on the retina and how it moves for different levels of visually demanding tasks is the subject of the current study. An Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO) was used to image, track and present Maltese cross, disk, concentric circles, Vernier and tumbling-E letter fixation targets to healthy subjects. During these different passive (static) or active (discriminating) fixation tasks under natural eye motion, the landing position of the target on the retina was tracked in space and time over the retinal image directly. We computed both the eye motion and the exact trajectory of the fixated target’s motion over the retina. We confirmed that compared to passive fixation, active tasks elicited a partial inhibition of microsaccades, leading to longer drifts periods compensated by larger corrective saccades. Consequently the fixation stability during active tasks was larger overall than during passive tasks. The preferred retinal locus of fixation was the same for each task and did not coincide with the location of the peak cone density.Competing Interest StatementThe authors have declared no competing interest.