title: Benefits of retinal image motion at the limits of spatial vision.
abstract: Even during fixation, our eyes are constantly in motion, creating an ever-changing signal in each photoreceptor. Neuronal processes can exploit such transient signals to serve spatial vision, but it is not known how our finest visual acuity-one that we use for deciphering small letters or identifying distant faces and objects-is maintained when confronted with such change. We used an adaptive optics scanning laser ophthalmoscope to precisely control the spatiotemporal input on a photoreceptor scale in human observers during a visual discrimination task under conditions with habitual, cancelled or otherwise manipulated retinal image motion. We found that when stimuli moved, acuities were about 25% better than when no motion occurred, regardless of whether that motion was self-induced, a playback of similar motion, or an external simulation. We argue that in our particular experimental condition, the visual system is able to synthesize a higher resolution percept from multiple views of a poorly resolved image, a hypothesis that might extend the current understanding of how fixational eye motion serves high acuity vision.
authors.affiliation: School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Kavitha
authors.initials: K
authors.lastname: Ratnam
authors.affiliation: Department of Ophthalmology, University of Bonn, Bonn, Germany.
authors.forename: Niklas
authors.initials: N
authors.lastname: Domdei
authors.affiliation: Department of Ophthalmology, University of Bonn, Bonn, Germany.
authors.forename: Wolf M
authors.initials: WM
authors.lastname: Harmening
authors.affiliation: School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Austin
authors.initials: A
authors.lastname: Roorda
mesh_terms: D000328:Adult; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009887:Ophthalmoscopy; D012160:Retina / Q000502:physiology*; D065855:Spatial Processing / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology