. 2021 Jan 21;11:2041. doi: 10.1038/s41598-021-81230-7

Table 2.

Comparison of the correlations between age and the slope of the NREM sleep EEG spectra in subjects with average and high intelligence (AIQ vs HIQ).

Recording location	ρ_AIQ	p_AIQ	N_AIQ	ρ_HIQ	p_HIQ	N_HIQ	p_difference
Fp1	.44	*< .001*	79	.40	*.001*	60	.787
Fp2	.44	*< .001*	85	.45	< .001	63	.901
F3	.48	*< .001*	84	.41	*.001*	64	.622
F4	.52	*< .001*	83	.42	*.001*	64	.476
Fz	.57	*< .001*	70	.45	< .001	60	.370
F7	.39	*.001*	70	.45	< .001	58	.660
F8	.45	*< .001*	69	.43	*.001*	59	.900
C3	.44	*< .001*	84	.45	< .001	64	.956
C4	.45	*< .001*	85	.43	< .001	64	.896
Cz	.47	*< .001*	70	.37	*.004*	60	.507
P3	.39	*< .001*	85	.42	*.001*	64	.801
P4	.42	*< .001*	85	.41	*.001*	64	.927
T3	.43	*< .001*	70	.49	< .001	59	.640
T4	.51	*< .001*	70	.42	*.001*	60	.507
T5	.32	*.007*	70	.45	*< .001*	58	.412
T6	.40	*.001*	70	.42	*.001*	60	.896
O1	.31	*.004*	85	.40	*.001*	64	.549
O2	.34	*.002*	84	.41	*.001*	64	.610

Spearman rank correlations (ρ) were significant in both intelligence groups, however, the differences between the higher (HIQ) and average (AIQ) intelligence groups was not significant (p_difference). Bold italic values indicate statistical significance at p < .017.