Fig. 2

a Sagittal T₁-weighted image with a 20-mm cubic VOI localized in the occipital visual cortex.b MR spectrum of a phantom containing NAA (2.01 ppm) and Lac (1.31 ppm).c Stack plot of spectra obtained before (B), during (stimulation 1, S1 and stimulation 2, S2) and following PS (after, A) in controls.d Stack plot of spectra obtained before (B), during (S1 and S2) and following PS (A) in MwoA patients. In vivo metabolites Lac (1.31 ppm), NAA (2.01 ppm), tCr (3.03 ppm) and Cho (3.19 ppm) are marked in the spectra