Table 1.

Models to regress PCC/PCu BOLD signal on age, GM, glutamate, and GABA

Model	R2	Adjusted R2	ΔR2	ΔF	p
1b
1	0.297	0.230	0.297	4.428	0.025
2	0.585	0.498	0.289	6.611	0.007
2b
1	0.132	0.049	0.132	1.593	0.227
2	0.530	0.431	0.398	8.055	0.003
3b
1	0.095	0.009	0.095	1.107	0.349
2	0.617	0.536	0.521	12.922	0.0003

Model 1 predictors: (constant), age, GM; model 2 predictors: (constant), age, GM, glutamate, GABA; dependent variable: PCC/PCu BOLD signal change.