Table 2.

Summary of the parameters for the spindles, including mean and standard deviation

Stage	Parameter	Mean	SD	PFA	PAD
N2	Spindle density (spindles per minute)	9.09	±2.84	0.33	0.04
	Mean spindle power (μV)	4.22	±0.55	0.50	0.02
N3	Spindle density (spindles per minute)	5.63	±3.29	0.31	0.04
	Mean spindle power (μV)	3.54	±0.50	0.58	0.11

The rightmost columns indicate the corrected p value for the most significant voxel of the correlation between the spindle parameter (row) and the DTI parameter (column). A significant correlation between AD and spindle power during sleep stage N2 was observed, indicating that axial diffusivity was higher in individuals with a stronger spindle power (Fig. 3). Furthermore, axial diffusivity was higher in individuals with a higher spindle density in sleep stages N2 and N3 in the temporal branch of the right inferior fronto-occipital fascicle (Fig. 3).