Effects of preprocessing on BOLD signal variance and age prediction
| Level of preprocessing | Voxel SDs | R2 between SD brain and age | R2 between mean brain and age |
|---|---|---|---|
| Basic | 0.72 (0.48) | 0.39 | 0.60 |
| Extended | 0.36 (0.20) | 0.81 | 0.59 |
″Basic″ preprocessing includes typical preprocessing steps (i.e., slice timing, motion correction, and spatial normalization and smoothing). ″Extended″ preprocessing includes independent components analysis, motion correction/white matter/cerebrospinal fluid parameter regression, and block normalization (see Materials and Methods). We calculated SDs over fixation blocks, and averaged them over brain and subjects. Between-subjects standard deviation of voxel SDs is given in parentheses. R2 values represent proportion of variance accounted for in models where age was predicted separately by SD-based and mean-based brain scores.