Table 2.

Results from quantitative evaluations of brain age estimation in the presence of nonlinear brain aging. We show results for 3 realistic simulations and a real dataset. The 3 simulations have different strengths of nonlinearity in brain age $Y^2\alpha$, with $\alpha =\mathrm{0,0.01},0.025$ respectively. Different rows are for different SVD dimensionality reductions, with the first in each experiment being with no use of SVD. We show mean absolute value of different brain age δ estimates (for the true δ in the simulations, it is 1.6y) and then correlations between estimated and true δ (for the simulations) and significance of associations with non-imaging variables (for real data), as above.