Interindividual differences among native right-to-left readers and native left-to-right readers during free viewing task

Abstract

Human visual exploration is not homogeneous but displays spatial biases. Specifically, early after the onset of a visual stimulus, the majority of eye movements target the left visual space. This horizontal asymmetry of image exploration is rather robust with respect to multiple image manipulations, yet can be dynamically modulated by preceding text primes. This characteristic points to an involvement of reading habits in the deployment of visual attention. Here, we report data of native right-to-left (RTL) readers with a larger variation and stronger modulation of horizontal spatial bias in comparison to native left-to-right (LTR) readers after preceding text primes. To investigate the influences of biological and cultural factors, we measure the correlation of the modulation of the horizontal spatial bias for native RTL readers and native LTR readers with multiple factors: age, gender, second language proficiency, and age at which the second language was acquired. The results demonstrate only weak or no correlations between the magnitude of the horizontal bias and the previously mentioned factors. We conclude that the spatial bias of viewing behaviour for native RTL readers is more variable than for native LTR readers, and this variance could not be demonstrated to be associated with interindividual differences. We speculate the role of strength of habit and/or the interindividual differences in the structural and functional brain regions as a cause of the RTL spatial bias among RTL native readers.