Seung Hyun Min¹, Chenyan Zhou¹, Jiawei Zhou¹; ¹School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, China

This study examined how temporal frequency influences binocular balance in normal and amblyopic observers. Twenty-three controls and 13 individuals with amblyopia participated in this study. Binocular balance was measured using an onset binocular rivalry task with sinusoidally flickering gratings at various temporal frequencies and static gratings paired with monocular attentional cues. For the flickering gratings, different combinations of temporal frequencies (2, 4, or 10 Hz in one eye vs. 2, 3, 4, 6, 10, 15, or 20 Hz in the other) were presented. Their effects were then compared, and their relationship was analyzed. The results showed no link between shifts in binocular balance due to temporal frequency and those caused by monocularly directed attention in either group. Intermediate temporal frequencies (6.5 - 9 Hz) in one eye maximized its perceptual dominance, with a larger shift due to temporal frequency in amblyopes than in controls. In normal observers, the balance shifts due to temporal frequency and attentional (active and passive) modulation were similar, whereas amblyopic observers exhibited a greater shift from temporal frequency than from monocularly focused passive attention. The findings indicate that intermediate temporal frequencies in one eye, rather than specific temporal frequency differences between the eyes, maximized perceptual dominance in both groups. Additionally, the influence of temporal frequency on binocular balance was stronger than that of monocularly directed passive attention in amblyopic individuals.