Presentation Information
[P2-14]Assessing Temporal Resolution in Amblyopic and Fellow Eyes Using the Two-Flash Fusion Paradigm
*Aysha Hamkari1, Gianluca Marsicano1, Katja Cundric1, David Melcher1 (1. New York University Abu Dhabi (United Arab Emirates))
Keywords:
amblyopia,temporal integration,visual perception,psychophysics
Amblyopia, traditionally viewed as a monocular visual disorder, is increasingly understood as a neurodevelopmental condition that affects cortical-level visual processing. While its effects on spatial vision are well-documented, less is known about how amblyopia may disrupt temporal integration - the brain’s ability to combine information over time into coherent percepts. This study investigates temporal integration in patients with amblyopia by using the two-flash fusion (2FF) task, which varies the interstimulus interval required to perceive two flashes as distinct. We hypothesize that the amblyopic eye will exhibit higher 2FF thresholds compared to the non-amblyopic eye, indicating impaired temporal resolution. As part of this ongoing study, four amblyopic participants with corrected-to-normal vision have so far completed psychophysical testing under binocular and two counterbalanced monocular conditions using eye patching. Preliminary results suggest that in some cases, the amblyopic eye exhibits higher 2FF thresholds compared to the non-amblyopic eye, indicating potential delays in temporal resolution and hence longer integration window for the amblyopic eye. However, other participants show relatively similar thresholds across both eyes, pointing to individual variability. There are also preliminary indications of asymmetries in performance across visual fields. We also implemented a staircase procedure to estimate personalized thresholds for the amblyopic eye and tailor ISI ranges for subsequent testing.These early findings suggest that temporal integration deficits in amblyopia may vary across individuals, potentially reflecting different degrees of cortical adaptation. Ongoing recruitment and psychometric modeling will help clarify underlying neural mechanisms. This work may contribute to the identification of non-invasive perceptual biomarkers to aid early detection and intervention in amblyopia.