Additionally, further limitations concern the implemented methodology: (A) the photon transport simulations have been generated with two distinct head atlases (Colin27 and SPM12), whose tissues’ geometries (e.g. scalp and skull thickness) may significantly differ from other adult individuals27; (B) our results should only be valid for adults, as we did not consider head atlases for children or infants45; (C) there is seemingly no gold standard on values for tissues’ optical properties, as recent studies based on photon transport simulations applied different values from one another27,30,31,46; (D) the fiducials points for each head atlas have been visually identified, while it has been shown that the visual identification of inion may be ambiguous12,47; (E) different tissue segmentation methods available may yield different thickness results48, although SPM12 has not been assessed yet; (F) the results provided as output of the toolbox are restricted to the 10–10/10–5 international systems positions12.