Improving vision in adult amblyopia by perceptual learning

TLDR

Practicing specific visual tasks induces perceptual learning that improves performance, and this learning is specific to basic stimulus features, implying primary visual cortex plasticity in adults. The study investigates whether low‑level perceptual learning can transfer to higher‑level visual tasks such as recognition. The authors carried out systematic low‑level training on adults with amblyopia, targeting the primary visual cortex to elicit changes that might benefit higher‑level visual functions. Training produced a two‑fold improvement in contrast sensitivity and letter‑recognition tasks, showing that perceptual learning can enhance basic visual representations in an adult system that did not develop during the critical period.

Abstract

Practicing certain visual tasks leads, as a result of a process termed “perceptual learning,” to a significant improvement in performance. Learning is specific for basic stimulus features such as local orientation, retinal location, and eye of presentation, suggesting modification of neuronal processes at the primary visual cortex in adults. It is not known, however, whether such low-level learning affects higher-level visual tasks such as recognition. By systematic low-level training of an adult visual system malfunctioning as a result of abnormal development (leading to amblyopia) of the primary visual cortex during the “critical period,” we show here that induction of low-level changes might yield significant perceptual benefits that transfer to higher visual tasks. The training procedure resulted in a 2-fold improvement in contrast sensitivity and in letter-recognition tasks. These findings demonstrate that perceptual learning can improve basic representations within an adult visual system that did not develop during the critical period.