What is Near-Infrared Spectroscopy (NIRS)?
Functional NIRS (fNIRS) is a specialized research imaging technique that uses near-infrared light to examine the function of the living brain. Research participants can be standing, sitting, lying down, or even engaged in active behaviors (walking, driving, exercising) while receiving an fNIRS scan. Small probes (plastic disks of about ¼ inch attached to optical fibers) are placed on the top of the head. There is no sensation of any kind from the infrared light, and it is not harmful. An actual fNIRS scan typically takes less than one hour. A participant might be asked to engage in a variety of activities during an fNIRS scan. Some activities might involve passively listening to sounds or seeing flashes, or performing learning, memory or other behavioral tasks. Participants might also be asked to play certain games or engage in activities on the computer or with an experimenter during the scan.
Near infrared spectroscopy (NIRS) is an increasingly popular technology for studying human brain function. NIRS systems are compact, have high temporal and spatial resolution and are cost effective. This makes functional NIRS (fNIRS) leading neuroimaging modality to investigate brain function under more realistic, ecologically valid conditions and in settings not possible with most other functional neuroimaging techniques.