Gaze and perception covary with reading direction

Abstract

Human observers prioritise the left visual field in perceptual judgements, a phenomenon widely attributed to cerebral asymmetries in vision. How stable are these mechanisms across differences in reading direction? We show that the classic left-side bias for faces is correlated with reading direction and tightly linked to gaze. Observers with varying proficiency in reading English (left-to-right) and Arabic (right-to-left) performed a chimeric face matching task (N = 271), with eye movements recorded in a subset (N = 115). The left-side bias scaled linearly with reading direction: strongest in English readers, reduced in bidirectional readers, and absent in Arabic readers. Reading direction also shifted gaze: English readers fixated further left on target faces and preferentially inspected faces in the left hemifield, and these gaze patterns predicted trial-by-trial perceptual judgements. These results suggest that cerebral asymmetries in face perception are flexible, coupled to gaze, and modified by reading direction.