In the context of previously proposed methods to address the definition of optodes position for fNIRS to target a set of brain regions-of-interest9–11, the main feature differentiating our method and developed toolbox is its simplification and consequent accessibility. The simplification relies on the fact that fOLD does not require digitalization of optodes positions nor individual structural scans, and the results of photon transport simulations have been computed offline and are readily available within the toolbox. Additionally, the accessibility of the method could be achieved by considering the 10–10 and 10–5 international systems as references for optodes arrangement and by relying on head atlases as templates for photon transport simulations. Thus, fOLD can be accessed and used by groups with different levels of expertise and background, while it does not require additional hardware (digitizer and MR scanner), nor further photon transport simulations. Nevertheless, the results are obtained independently of anatomic variances between-subjects, and it requires the optodes to be precisely placed in accordance to the international systems12. In agreement with the conclusions presented by Machado et al.9, we believe that these simplifications are acceptable for fNIRS non-clinical applications. Also, Wijeakumar et al.10 had reported significant correlation of the results obtained for subject-specific and head atlas in adults. Finally, using head atlases as templates facilitates both the application of brain parcellation atlases (Methods section) and the fNIRS positions definition based on meta-analyses (Toolbox section), as the latter was also envisioned by Wijeakumar et al.10 as a future approach to identify ROIs.