Macular degeneration affects eye movement behavior during visual search

Patients with a scotoma in their central vision (e.g., due to macular degeneration, MD) commonly adopt a strategy to direct the eyes such that image falls onto a peripheral location on the retina. This location is to as the preferred retinal locus (PRL). Although previous research has investigated the characteristics of this PRL, it is unclear whether eye metrics are modulated by peripheral viewing with a PRL as measured visual search paradigm. To this end, we tested four MD patients in a search paradigm and contrasted their performance with a healthy control a healthy control group performing the same experiment with a simulated The experiment contained two conditions. In the first condition the unfilled circle hidden among c-shaped distractors (serial condition) and second condition the target was a filled circle (pop-out condition). search latencies for the MD group were significantly longer in both compared to both control groups. Results of a subsequent experiment that this difference between the MD and the control groups could not be by a difference in target selection sensitivity. Furthermore, search MD patients was associated with saccades with smaller amplitudes toward scotoma, an increased intersaccadic interval and an increased number of movements necessary to locate the target. Some of these characteristics, the increased intersaccadic interval, were also observed in the which indicate that these characteristics are related to the peripheral itself. We suggest that the combination of the central scotoma and viewing can explain the altered search behavior and no behavioral found for a possible reorganization of the visual system associated with of a PRL. Thus the switch from a fovea-based to a PRL-based reference impairs search efficiency.