Functional Near-infrared Spectroscopy (fNIRS) is a device designed to detect changes in the concentration of oxygenated (oxyHb) and deoxygenated (deoxyHb) haemoglobin molecules in the blood, a method commonly used to assess cerebral activity. fNIRS is a type of functional neuroimaging technology that offers a relatively non-invasive, safe, portable, and low-cost method of indirect and direct monitoring of brain activity.