Functional Near-Infrared Spectroscopy

**Semantic type:** Laboratory Procedure

**Definition:** A hemodynamic, noninvasive optical imaging technique that measures changes in the concentration of oxy- and deoxy-hemoglobin (Hb), as well as the changes in the redox state of cytochrome-c-oxidase, within the brain by means of the characteristic absorption spectra of Hb in the near-infrared range. It is used to monitor cognitive states and brain activity.

**Synonyms:** - Functional NIR Spectroscopy - Functional Near Infrared Spectroscopy - Functional Optical Brain Imaging - fNIRS