This study aims at understanding the effects of homogeneous visual field defects on ocular movements and exploratory patterns according to their peripheral or central location. A gaze-contingent paradigm was implemented in order to display images to the participants while masking in real-time either central or peripheral areas of the participant's field of view. Results indicate a strong relation between saccade amplitudes and mask sizes. Fixations are predominantly directed toward parts of the scene which are left unmasked. In a second set of analyses, we defined relative angle as an angle between a saccade vector and a preceding one. We show that backward saccades are more frequently produced with central masking. As for peripheral masking, we observe that participants explore the scene in a sequential scanning pattern seldom foveating back to an area attended in the previous seconds. We discuss how masking conditions affect ocular behaviours in terms of exploratory patterns, as well as how relative angles unveil characteristic information distinguishing the two masking conditions from each other and from control subjects.
Erwan J. David, Patrick Le Callet, Matthieu Perreira Da Silva, Pierre Lebranchu, "How are ocular behaviours affected by central and peripheral vision loss? A study based on artificial scotomas and gaze-contingent paradigm." in Proc. IS&T Int’l. Symp. on Electronic Imaging: Human Vision and Electronic Imaging, 2018, pp 1 - 6, https://doi.org/10.2352/ISSN.2470-1173.2018.14.HVEI-504