A review of interactions between peripheral and foveal vision

Abstract

Visual processing varies dramatically across the visual field. These differences start in the retina and continue all the way to the visual cortex. Despite these differences in processing, the perceptual experience of humans is remarkably stable and continuous across the visual field. Research in the last decade has shown that processing in peripheral and foveal vision is not independent, but is more directly connected than previously thought. We address three core questions on how peripheral and foveal vision interact, and review recent findings on potentially related phenomena that could provide answers to these questions. First, how is the processing of peripheral and foveal signals related during fixation? Peripheral signals seem to be processed in foveal retinotopic areas to facilitate peripheral object recognition, and foveal information seems to be extrapolated toward the periphery to generate a homogeneous representation of the environment. Second, how are peripheral and foveal signals re-calibrated? Transsaccadic changes in object features lead to a reduction in the discrepancy between peripheral and foveal appearance. Third, how is peripheral and foveal information stitched together across saccades? Peripheral and foveal signals are integrated across saccadic eye movements to average percepts and to reduce uncertainty. Together, these findings illustrate that peripheral and foveal processing are closely connected, mastering the compromise between a large peripheral visual field and high resolution at the fovea. Brief overview of differences between peripheral and foveal vision Although the human eye is often compared to a photographic camera, processing across the visual field is not homogeneous like in a camera film or a digital sensor. First, there are gaps in sensory information due to several anatomical properties of the eye: (a) there are no photoreceptors in the optic disc, where the axons of the retinal ganglion cells exit the eyeball: this leads to a blind spot (Mariotte, 1740, cited after Ferree & Rand, 1912; Grzybowski & Aydin, 2007). (b) The center of the retina contains only cone, but no rod photoreceptors (Schultze, 1866; Oesterberg, 1935; Curcio, Sloan, Kalina, & Hendrickson, 1990), leading to a central scotoma under dark illumination conditions. (c) Because photoreceptors are located on the back side of the retina, away from the light, blood vessels cast shadows on them (Purkinje, 1819; von Helmholtz, 1867; Evans, 1927; Adams & Horton, 2002). The second striking difference to a photographic camera is that the processing of visual signals varies quite dramatically across the visual field. Here, an important distinction arises between the center of the visual field, called the fovea, and the rest, called the periphery. 1 We only briefly highlight some of the key differences in processing and perception between the fovea and the periphery because these have been reviewed in detail elsewhere

Distractor filtering is affected by local and global distractor probability, emerges very rapidly but is resistant to extinction

“…In the case of distractor suppression, the short-term memory system would be responsible for the almost instantaneous buildup of local inhibition at likely distractor locations, whereas the long-term memory system would be responsible for its stability over longer time periods. Notice that the fact that humans can learn both quickly and stably is clearly established in the case of sensorimotor contingencies—for instance, in the case of saccade adaptation (e.g., McLaughlin, 1967 ) or transsaccadic perceptual recalibration (Valsecchi et al, 2020 ). Accordingly, it has been suggested that the capacity to learn at different time scales is a general property of the nervous system, from low-level sensorimotor learning, to higher-level cognitive learning (Kording et al, 2007 ).…”

Prediction of complex stimuli across saccades

“…How is it possible that humans can recognize objects and people in their peripheral view even though retinal resolution is relatively low there? Answers to this question focus on the special role of previous experience gathered while moving the eyes (e.g., Stewart, Valsecchi, & Schütz, 2020 ; von Helmholtz, 1925 ). It has been suggested that these experiences are used by a transsaccadic prediction mechanism to facilitate peripheral object recognition ( Herwig & Schneider, 2014 ).…”

Stronger saccadic suppression of displacement and blanking effect in children

“…With every saccade, the presaccadic stimulus features and location must be reconciled with their postsaccadic counterpart in order to maintain a stable percept of the world. The visual system may achieve this transsaccadic perceptual stability by integrating pre- and postsaccadic feature information (Demeyer, Graef, Wagemans, & Verfaillie, 2010a; Ganmor, Landy, & Simoncelli, 2015 ; Wijdenes, Marshall, & Bays, 2015 ; Wolf & Schütz, 2015 ; Stewart, Valsecchi & Schütz, in press ) or location information ( Cicchini, Binda, Burr, & Morrone, 2013 ; Prime, Niemeier, & Crawford, 2005 ), or by suppressing small displacements that occur during the saccade ( Bridgeman, Hendry, & Stark, 1975 ). However, it is unknown when such mechanisms develop.…”

“…However, transsaccadic feature integration is not necessarily an automatic process and may not occur without specific task demands ( Stewart & Schütz, 2018b ; Stewart & Schütz, 2019b ; Stewart, Valsecchi & Schütz, in press ); similarly, it is not mandatory for pre- and postsaccadic location information to be fully integrated. This leads to the “under which conditions” part of the above question.…”