Figure 6.

Spindle feature by age for the top 5 regression models by central frequency (fc). In older patients, fast spindles had a slightly higher frequency relative to younger patients, despite the decreased spindle density, and poor performance on fluid cognitive tests was linked with higher fast spindle FFT averages. The color bar represents absolute scores for fluid cognition from the NIH Toolbox Cognition Battery. Each data point represents one patient. AMP, Amplitude; FFT, Frequency; DENS, Density; DUR, Duration.