Foveational complexity in single word identification: contralateral visual pathways are advantaged over ipsilateral pathways

Small temporal asynchronies between the two eyes in binocular reading: Crosslinguistic data and the implications for ocular prevalence

We investigated small temporal nonalignments between the two eyes’ fixations in the reading of English and Chinese. We define nine different patterns of asynchrony and report their spatial distribution across the screen of text. We interpret them in terms of their implications for ocular prevalence—prioritizing the input from one eye over the input from the other eye in higher perception/cognition, even when binocular fusion has occurred. The data are strikingly similar 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 cue higher processing to prioritize the input from that eye, during and after binocular fusion.

Differential vergence movements in reading Chinese and English: Greater fixation-initial binocular disparity is advantageous in reading the denser orthography

We explore two aspects of exovergence: we test whether smaller binocular fixation disparities accompany the shorter saccades and longer fixations observed in reading Chinese; we test whether potentially advantageous psychophysical effects of exovergence (cf. Arnold & Schindel, 2010; Kersten & Murray, 2010) transfer to text reading. We report differential exovergence in reading Chinese and English: Chinese readers begin fixations with more binocular disparity, but end fixations with a disparity closely similar to that of the English readers. We conclude that greater fixation-initial binocular fixation disparity can be adaptive in the reading of visually and cognitively denser text.

Detection of spatial frequency in brain-damaged patients: influence of hemispheric asymmetries and hemineglect

Hemispheric specialization for spatial frequency processing was investigated by measuring the contrast sensitivity curves of sine-wave gratings in 30 left or right brain-damaged patients using different spatial frequencies compared with healthy participants. The results showed that left brain-damaged patients were selectively impaired in processing high frequencies, whereas right brain-damaged patients were more impaired in the processing low frequencies, regardless of the presence of visuo-spatial neglect. These visual processing results can be interpreted in terms of spatial frequency discrimination, with both hemispheres participating in this process in different ways.