How to design real-world functional near-infrared spectroscopy (fNIRS) studies: a primer

Significance: Functional near-infrared spectroscopy (fNIRS) is a unique neuroimaging methodology with high portability and tolerance of motion, making it well-suited to research in dynamic real-world environments. However, it is crucial to carefully design fNIRS paradigms to suit the unique requirements of real-world research settings. This paper outlines key design principles and considerations for fNIRS studies.Aim: In this paper, we address the lack of guidance on experimental design for fNIRS, which in our growing field can help to educate new fNIRS researchers and improve the quality and applicability of fNIRS research across various settings. Approach: Here, we provide a primer for how to design fNIRS studies and overcome challenges in fNIRS experimental design, with a focus on naturalistic real-world research which has gathered increased research interest in recent years.Conclusions: We conclude by outlining seven key design principles researchers can use to guide experimental design for fNIRS research.