Saccadic compression of time as a marker for Developmental Dyslexia

Abstract

SummaryAbout 10% of the world’s population is dyslexic, experiencing reading impairments unrelated to cognitive deterioration. Due to its impact, identifying the mechanisms subtending dyslexia is paramount. However, while most research focused on the eye movements’ phenomenology, none investigated their perceptual, transient consequences. In fact, it has been shown that rapid eye movements (i.e., saccades) are accompanied by temporary distortions of space and time. Such distortions have been linked to the receptive fields’ predictive remapping, which anticipates the movement and compensates for the gaze’s displacement. Here, we demonstrate that dyslexic children show reduced flexibility in modulating temporal information around the saccadic onset. Moreover, accuracy oscillations within the delta band, phase-locked to the saccade’s onset, preceded transient temporal compression in typical readers. Conversely, no oscillatory behavior was observed in dyslexic participants, suggesting that the absence of transient temporal distortions originated from the mismatch between the anticipatory remapping and the saccadic onset.