Linking behavioral deficits with underlying neural property changes in amblyopia

While it is widely accepted that abnormal visual experience during critical period can lead to significant functional deficits and altered neural property, the quantitative link between behavioral visual losses and underlying neural changes remains elusive. To address this gap, we systematically varied stimulus orientation and contrast to measure 2D psychometric functions of amblyopic and normally sighted participants at two different spatial frequencies. A biologically-interpretable neural population model explicitly incorporated with neural contrast response function (CRF) and orientation tuning property accounted for the complex performance data for both groups. Our results revealed that the poor performance in the amblyopic group can be excellently explained by a rightward-shifted CRF at higher spatial frequency and reduced population Fisher information for coding orientation. Moreover, regression analysis revealed that the behavior contrast threshold from an independent measurement significantly depended on the neural properties estimated by the model. This study demonstrates the potential of biologically-interpretable models to quantitatively bridge the gap between behavioral deficits and underlying neural changes, offering a promising tool for understanding normal and abnormal visual systems.