Figure 3
From: Aging affects gain and internal noise in the visual system
The correlations between contrast sensitivity and internal additive noise at all spatial frequencies at the low, medium and high noise levels for young and old groups, respectively. Data from all observers were pooled. ‘Y’ denotes the young group; ‘O’ denotes the old group; ‘Low’ denotes the condition of the low noise level; ‘Medium’ denotes the condition of the medium noise level; ‘High’ denotes the condition of the high noise level. The data were the residual plus mean values after excluding the effect of spatial frequency.
