68 Chapter 3 over time, while subgroups with the highest amyloid burden (3rd third, 4th quarter, 5th fifth and K-high) showed memory decline over time (Figure 2). Memory slopes of individuals in the grey zone were intermediate, with beta’s closer to zero or negative, shown most clearly in the grey zone (0.19-0.29 BPND) and the 4th fifth (0.14-0.22 BP ND, 0.21-1.31 SUVr, Figure 2). Figure 2. Estimated longitudinal change on RAVLT delayed recall