Abstract
Purpose :
The association between facial perception ability and stimulus intensity in adult with amblyopia remains unclear. We speculate that there is a functional relationship between face perception ability and stimulus signal intensity in adult amblyopia, and the threshold value of face recognition ability can be quantified.
Methods :
Stimulus Design
Twelve adults with amblyopia (mean age 28.83± 5.4 years SEM) and ten health controls were recruited in this study. We began with sensory responses ranging from 1% to 80% and created six external noise points using MATLAB.We combined three pure noise images with different standard deviations (64, 256, and 1024) in specific proportions. All images were randomized during generation. These were merged with face images adjusted by a mixed parameter λ.
Behavioral experiments
A sham-controlled, cross-over, double-blind study design was adopted. All patients received perceptual learning with the task of identifying face pictures under the condition of BCVA. One session of training contained 120 face judgement trails, including six noise gradients, each containing 20 images of faces which appeared randomly. Session was repeated twice with each eye. Patients could choose to rest for minutes after every block.
Statistical Analysis
The two groups do not follow a normal distribution, so we utilized a rank-sum test to analyze if there exists a statistical difference in the perceptual responses between the two groups. Subsequently, we employed Origin software for visualization, aiming to explore the abnormality in facial recognition ability among adult amblyopic patients.
Results :
Notably, at a noise level of 0.8, a statistically significant difference (p=0.004, p<0.05) in accuracy rates between the amblyopic and control groups was observed. We plotted face perception cognitive curves for the amblyopia and normal groups, using stimulus intensity on the horizontal axis and subjects' sensory response on the vertical axis.
Conclusions :
Facial recognition ability in adult amblyopic patients is lower compared to health controls.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.