Intermediate
fNIRS (functional near-infrared spectroscopy)
Also known as: Near-infrared spectroscopy, TD-fNIRS, Optical brain imaging
A wearable method that shines near-infrared light through the scalp to measure blood-oxygen changes linked to brain activity.
Active brain regions use more oxygen, which changes how they absorb near-infrared light. fNIRS tracks this, much like a portable, lower-resolution fMRI. It’s slower than EEG (seconds rather than milliseconds) and copes better with movement. Kernel Flow is a high-end example.
Last updated Sep 30, 2026. Educational content, not medical advice.