Broad bandwidth of perceptual learning in the visual system of adults with anisometropic amblyopia

TLDR

Training adult amblyopes in simple visual tasks improves spatial vision, but the extent of generalization to other stimuli and tasks remains unclear. The study aimed to estimate and compare the bandwidth of perceptual learning between anisometropic amblyopes and normal observers. Contrast sensitivity functions to sine‑wave gratings across spatial frequencies were measured before and after single‑frequency training in teenagers and adults with and without amblyopia. The amblyopic visual system exhibited a much broader bandwidth of perceptual learning than the normal system, indicating greater plasticity and supporting its use as a treatment for amblyopia.

Abstract

Recent studies have demonstrated that training adult amblyopes in simple visual tasks leads to significant improvements of their spatial vision. One critical question is: How much can training with one particular stimulus and task generalize to other stimuli and tasks? In this study, we estimated the bandwidth of perceptual learning in teenage and adult observers with anisometropic amblyopia and compared it to that of normal observers. We measured and compared contrast sensitivity functions-i.e., sensitivity to sine-wave gratings of various spatial frequencies-before and after training at a single spatial frequency in teenagers and adults with and without amblyopia. We found that the bandwidth of perceptual learning in the amblyopic visual system is much broader than that of the normal visual system. The broader bandwidth, suggesting more plasticity and wider generalization in the amblyopic visual system, provides a strong empirical and theoretical basis for perceptual learning as a potential treatment for amblyopia.