Table 2. Between-events effect analysis of SSO features.

	Factors
	Sleep Stage		Origin Location
	p-val	Level comparisons	p-val
Features	prob.		prob.
NP Amplitude	<0.001	SWS>S2	NS
N Amplitude	NS	–	NS
P Amplitude	<0.01	SWS>S2	NS
NP Time	<0.01	SWS>S2	<0.001
ZN Time	NS	–	NS
slope 1	NS	–	<0.01
slope 2	<0.01	S2>SWS	<0.05

The results corresponding to each feature have been organized in two main columns related to the Sleep Stage and Origin Location factors. In the first column, significance and direction of difference between SWS and NREM Sleep Stage 2 are shown; while in the second column, significance of Origin Location effect is reported.