fNIRS samples a banana-shaped brain region roughly halfway between source and detector.
Evidence
In the fNIRS imaging system optodes are placed at various locations on the scalp. Each fNIRS channel consists of a paired source and detector. The source emits a light beam, directed perpendicular to the scalp surface, and the detector detects the light emerging from the brain. The detected light beam has scattered in a banana-shaped pathway through the brain reaching a depth of approximately half the distance between the source and detector. — Dijk, Pim van, Physiology, Psychoacoustics and…, 4274
Categorization
Category: Definitional Content
- DEFINE: Explains how optode geometry determines what brain tissue an fNIRS channel actually samples.