Synchrony and asynchrony of the two eyes in binocular fixations in the reading of English and Chinese; the implications for ocular prevalence

We explore low-level, behavioural universals in reading, across English and Chinese. We investigated binocular coordination in terms of the small non-alignments between the two eyes' fixations in time. We define a typology of nine such asynchronies and report the different spatial distributions of these types across the screen of text. We interpret them in terms of their implications for ocular prevalence-the prioritizing of the input from one eye over the input from the other eye in higher perception/cognition, after binocular fusion. The results show striking similarities of binocular reading behaviours across the two very different orthographies. Asynchronies in which one eye begins the fixation earlier and/or ends it later occur most frequently in the hemifield corresponding to that eye. We propose that such small asynchronies in binocular fixations prioritize the higher processing of the input from that eye, after binocular fusion.