Abstract:

PURPOSE: Anisometropic amblyopia, one type of lazy eye, is a neuronal vision disorder accompanied with weak or strong spatial vision loss in the amblyopic eye (AE) when compared to normal eyes. While the plausible neural substrates and consequences on visual perception have been studied, its relation to changes of monocular early neuronal processing remains unclear.
METHODS: Here we used the monocular tilt illusion as a probe of primary visual cortex inhibitory interactions and we modeled amblyopic low-level perception disturbances through network modi?cations at monocular V1 stages.
RESULTS: We found that the amount of orientation misperception was higher in AEs when compared with non-amblyopic (NAEs) and neurotypical eyes (NTEs). Importantly, it was highly correlated to subject's AE peak contrast sensitivity. Near the peak of contrast sensitivity, the model predicted from the tilt data a broader orientation tuning width of AEs than NAEs and NTEs without any relation to subjects' contrast sensitivity functions (CSF).Additionally, for subjects with stronger loss of peak CSF, these correlations could be explained by stronger lateral inhibition in AEs.
CONCLUSIONS: Through psychophysics experiments in humans and computational modeling of V1, our study provides new fundamental insights into visual neuronal disorders through inhibitory prevalence.

Key words: Anisometropic amblyopia, lateral inhibition, tilt illusion, monocular early neuronal processing, model