Table 1.

Data quality metrics for the tissue-corrected GABA⁺ levels and segmentation results

Region	Group	N	Data quality metrics				Tissue segmentations
			Fit error (%)	NAA SNR	GABA SNR	FreqStDevHz	GM	WM	CSF
LSM1	Young	30	4.11 ± 1.25	392 ± 74	28 ± 4	0.46 ± 0.28	0.34 ± 0.03	0.60 ± 0.04	0.06 ± 0.02
	Older	27	4.44 ± 1.60	296 ± 88	23 ± 4	0.73 ± 0.29	0.26 ± 0.03	0.62 ± 0.04	0.12 ± 0.03
	p value		0.395	<0.001	<0.001	0.001	<0.001	0.052	<0.001
Pre-SMA	Young	27	7.04 ± 1.60	406 ± 58	27 ± 5	0.51 ± 0.32	0.53 ± 0.03	0.32 ± 0.04	0.15 ± 0.03
	Older	22	7.10 ± 2.07	307 ± 65	23 ± 4	0.69 ± 0.24	0.45 ± 0.03	0.32 ± 0.04	0.23 ± 0.04
	p value		0.903	<0.001	0.001	0.038	<0.001	0.707	<0.001
RIFC	Young	29	5.32 ± 1.47	304 ± 44	21 ± 4	0.57 ± 0.29	0.56 ± 0.04	0.37 ± 0.05	0.08 ± 0.03
	Older	29	5.25 ± 1.53	264 ± 47	20 ± 4	0.96 ± 0.43	0.47 ± 0.04	0.40 ± 0.05	0.13 ± 0.04
	p value		0.848	0.001	0.444	<0.001	<0.001	0.010	<0.001
LSTR	Young	22	6.61 ± 1.83	225 ± 38	19 ± 4	0.80 ± 0.55	0.58 ± 0.03	0.35 ± 0.03	0.08 ± 0.01
	Older	21	6.76 ± 1.90	198 ± 36	16 ± 4	1.06 ± 0.53	0.51 ± 0.03	0.35 ± 0.04	0.14 ± 0.03
	p value		0.796	0.021	0.005	0.131	<0.001	0.770	<0.001
RSTR	Young	23	7.10 ± 2.26	263 ± 46	19 ± 4	0.64 ± 0.42	0.58 ± 0.03	0.33 ± 0.03	0.09 ± 0.01
	Older	25	7.13 ± 1.89	212 ± 23	17 ± 3	1.02 ± 0.44	0.51 ± 0.03	0.34 ± 0.04	0.15 ± 0.03
	p value		0.966	<0.001	0.012	0.004	<0.001	0.827	<0.001
OCC	Young	30	4.27 ± 0.80	375 ± 67	23 ± 4	0.53 ± 0.31	0.66 ± 0.04	0.26 ± 0.04	0.08 ± 0.02
	Older	25	5.30 ± 1.31	294 ± 61	18 ± 4	0.90 ± 0.44	0.56 ± 0.04	0.30 ± 0.03	0.14 ± 0.03
	p value		0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

Data are shown as the mean ± SD.