1. Figure Legend: From: Crowding and eccentricity determine reading rate
Journal of Vision. 2007;7(2):20. doi: /7.2.20
Figure Legend:
Effects of eccentricity. Based on the data in Figure 12. (a) The maximum reading rate estimated by Chung et al. (1998) from their two-line fit to the data at each vertical eccentricity (in lower visual field). This is a big effect; reading rate drops sixfold from 0° to 20°. While there is no known reason for any of these graphs to be straight, the linear regression lines do fit well enough for us to take their log-linear slope as a summary of the eccentricity dependence. The mean slope of the regression lines in (a) is −0.04 decade/deg, with a standard deviation of Note that, in the model (Eq. 3), reading rate r (character per second) is the product ρu, so log r = log ρ + log u and d⁢log⁢rdφ=d⁢log⁢ρdφ+d⁢log⁢udφ. Thus, the slopes of log ρ (panel b) and log u (panel c) must sum to the slope of log r (panel a). (b) The rate factor ρ at each eccentricity. The mean slope is −0.05 decade/deg. (c) The uncrowded span u = 1 + 2/b for large spacing (Eq. B8) at each eccentricity. The mean slope is decade/deg. The drop in r is accounted for by the drop in ρ; there is no drop in u for these observers. English text has an average of 5 printed characters and a space for each word so 1 word/min = (5 + 1 character) / (60 s) = 0.1 character/s. (d) Bouma's factor b. Note that there is much less variation in this Chung et al. group of observers than in the Legge et al. (2001) observers plotted in Figure 8.
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