Table 1. Results of the path analysis.

Model	RMSEA	GFI	AGFI	AIC
Two paths model
NAA→fMRI signal→behaviora	<0.001	0.990	0.940	10.462
fMRI signal→NAA→behavior	0.660	0.800	−0.198	24.054
NAA and fMRI signal→behavior	0.558	0.837	0.024	20.333
One path model
NAA→behavior	0.383	0.832	0.497	18.794
fMRI signal→behavior	0.611	0.729	0.188	32.387

Abbreviations: AGFI, adjusted goodness-of-fit index; AIC, Akaike information criterion; fMRI, functional magnetic resonance imaging; GFI, goodness-of-fit index; NAA, N-acetylaspartate; RMSEA, root mean square error of approximation.

^aOptimal model.