Parafoveal magnification: visual acuity does not modulate the perceptual span in reading
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Updated: Jun 22, 2026

A Gaze-Contingent Display Framework for Perceptual Learning Research with Simulated Central Vision Loss
Published on: April 11, 2025
Sébastien Miellet1, Patrick J O'Donnell, Sara C Sereno
1University of Glasgow, Glasgow G12 8QB, Scotland, United Kingdom. s.miellet@psy.gla.ac.uk
Abstract:
Models of eye guidance in reading rely on the concept of the perceptual span-the amount of information perceived during a single eye fixation, which is considered to be a consequence of visual and attentional constraints. To directly investigate attentional mechanisms underlying the perceptual span, we implemented a new reading paradigm-parafoveal magnification (PM)-that compensates for how visual acuity drops off as a function of retinal eccentricity. On each fixation and in real time, parafoveal text is magnified to equalize its perceptual impact with that of concurrent foveal text. Experiment 1 demonstrated that PM does not increase the amount of text that is processed, supporting an attentional-based account of eye movements in reading. Experiment 2 explored a contentious issue that differentiates competing models of eye movement control and showed that, even when parafoveal information is enlarged, visual attention in reading is allocated in a serial fashion from word to word.
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