Abstract
Vision aid optical elements, such as progressive additional power lenses, spatially distort the image of the natural environment disparately across the different parts of the visual field. Eye movements thereby continuously shift the distortions in the retinal plane. While people adapt to such spectacles, the visual system seems to compensate for distortions regardless of their continuous retinal displacements during eye movements. Neural mechanisms involved in distortion adaptation might transfer their plasticity across saccades. Here we used reference frames of adaptation aftereffects to assess if distortion is processed anew at every fixation or if it is retained across saccades to achieve perceptual stability. In a psychophysical experiment, observers viewed geometrically skewed natural image content for 8 minute to induce adaptation. A saccade was subsequently executed to a new fixation point and skew adaptation was measured at retinotopic and spatiotopic locations as well as at a location which was neither retinotopic nor spatiotopic. Adaptation aftereffects were tested in an adjustment procedure. The adaptation aftereffect, i.e. the point of subjective equality (PSE), was defined by the skew amplitude of the test stimuli which was perceived to be undistorted by the observers. The skew adaptation information was partially transferred to the new fixation. Retinotopic and spatiotopic locations showed significant skew adaptation aftereffect wherein the PSE shifted in the direction of the adapting skew direction. In contrast, no aftereffect was observed at the location which was neither retinotopic nor spatiotopic. Therefore, the visual system preserves retinotopic and spatiotopic distortion information across saccades. The spatiotopic distortion information is conceivably used to counterbalance the saccade induced retinal shifts of the distortions, thereby mediating retinotopic and spatiotopic representations of the distortions.
Meeting abstract presented at VSS 2017