Foveal

About: Foveal is a research topic. Over the lifetime, 2652 publications have been published within this topic receiving 94120 citations.

Calculations of two-dimensional foveal retinal images in real eyes.

Abstract: Foveal point-spread functions are computed from experimental wave-aberration data for individual emmetropic subjects. The effects of pupil size and image focus are considered in the calculations. Foveal images of extended test objects are generated from the point-spread functions corresponding to different image-quality situations. Wiener-filtered test objects are also computed to obtain a partial compensation of the spatial degradation introduced by the eye’s optical system in the visual process.

Unique hue judgments as a function of test size in the fovea and at 20-deg temporal eccentricity.

Abstract: Unique hue loci were measured for four observers in the fovea and at 20-deg temporal eccentricity as a function of test size. Eccentric measurements were made on the cone plateau following a rod bleach. The results indicate that unique yellow remains approximately invariant with respect to test size and retinal eccentricity, whereas unique blue and unique green shift to longer wavelengths with increasing test size. The locus of unique blue in the periphery reaches an asymptote at approximately the same wavelength as that from the foveal measurements, whereas unique green measured in the periphery is consistently at shorter wavelengths than in the fovea. In general, the data are best described by a model in which the short-wavelength-sensitive cone input to the two opponent-color channels decreases with decreasing test size and increasing retinal eccentricity.

Reading strategy modulates parafoveal-on-foveal effects in sentence reading

Abstract: Task demands and individual differences have been linked reliably to word skipping during reading. Such differences in fixation probability may imply a selection effect for multivariate analyses of eye-movement corpora if selection effects correlate with word properties of skipped words. For example, with fewer fixations on short and highly frequent words the power to detect parafoveal-on-foveal effects is reduced. We demonstrate that increasing the fixation probability on function words with a manipulation of the expected difficulty and frequency of questions reduces an age difference in skipping probability (i.e., old adults become comparable to young adults) and helps to uncover significant parafoveal-on-foveal effects in this group of old adults. We discuss implications for the comparison of results of eye-movement research based on multivariate analysis of corpus data with those from display-contingent manipulations of target words.

Learning patterns of eye motion for foveal pursuit.

Abstract: Two human subjects fixated a small light oscillating sinusoidally. After the light disappeared, sinusoidal post-pursuit eye motion (PPEM) continued to follow the unexpected trajectory of targets oscillating at 0.8 and 1.0 Hz. Saccades corrected differences between eye and expected target position during PPEM in complete darkness. Predictive tracking, the ability of primates to accurately fixate even rapidly moving targets, may thus involve learning specific eye movement patterns that mimic target motion.