Figure 11.

The relationship between scan length and noise variance. Results are shown using untranformed correlations (C, shown in red) and Fisher-transformed correlations (Z, shown in teal) to compute the noise variance. Panel (a) shows diminishing session-to-session variance as scan length increases. Panel (b) shows how the adjustment factor $\theta \left(t\right)={\sigma }_U^2\left(t\right)∕{\sigma }_U^2(t∕2)$ changes as t increases. The fitted line relating θ(t) to log(t) is shown in black.