Functional Near-Infrared Spectroscopy

# Functional Near-Infrared Spectroscopy **Entity class:** Concept or analytic term **Domain:** Neuroimaging / Neural Interfaces **Doc Type:** Scientific Concept Node **Maturity:** Established and Evolving **Related:** [[Non-Invasive BCI]], [[Multimodal Neural Data Fusion]], [[Functional Magnetic Resonance Imaging]] --- ## Definition **Functional near-infrared spectroscopy (fNIRS)** estimates cortical hemodynamic activity by measuring changes in the absorption of near-infrared light associated with oxygenated and deoxygenated hemoglobin. It is more portable than fMRI but has shallower spatial reach and an indirect relationship to neuronal firing. ## Interface relevance fNIRS can support mobile or multimodal BCI experiments, particularly when fused with faster electrical or magnetic measurements. Its optode geometry, wavelength, sampling, motion correction, and physiological confounds must be retained as metadata. ## Neurotech source route **Collection:** [[collections/Neurotech|Neurotech]] **Source article:** [[articles/The Organic-Synthetic Brain Atlas|The Organic-Synthetic Brain Atlas]] ## Relationships [[wiki/Functional Near-Infrared Spectroscopy|Functional Near-Infrared Spectroscopy]] is related to [[wiki/Neural Signal Acquisition|Neural Signal Acquisition]] as portable optical measurement of cortical hemodynamics.  This entry's documented connections are expressed in its definition and related-work routes, with provenance retained in the source-linked material.  ## Neurotech cluster route **Collection:** [[collections/Neurotech|Neurotech]] **Source articles:** [[articles/The Architecture of Continuity and Emerging Neuroinformatics Standards|The Architecture of Continuity and Emerging Neuroinformatics Standards]] · [[articles/The Organic-Synthetic Brain Atlas|The Organic-Synthetic Brain Atlas]] ## Related Work in the Corpus  - In [[articles/The Organic-Synthetic Brain Atlas|The Organic-Synthetic Brain Atlas]], **Movement V — Functional Integration and Readout: Activity, Imaging, and Dynamic Coupling** provides the narrative context for **Functional Near-Infrared Spectroscopy**: Wiki route: neural signal acquisition · fMRI · fNIRS · functional ultrasound · Neuropixels · optogenetics and chemogenetics. - In [[articles/The Organic-Synthetic Brain Atlas|The Organic-Synthetic Brain Atlas]], **VI.3 — fNIRS Portability and the Wearable Decoding Path** provides the narrative context for **Functional Near-Infrared Spectroscopy**: The fMRI infrastructure that supports the Huth-Tang decoder requires room-scale superconducting magnet systems and is unlikely to be the eventual deployment substrate for semantic decoding. - In [[articles/The Architecture of Continuity and Emerging Neuroinformatics Standards|The Architecture of Continuity and Emerging Neuroinformatics Standards]], ****3\. Standardization of Brain-Computer Interfaces (BCI)**** provides the narrative context for **Functional Near-Infrared Spectroscopy**: Acquisition modalities: EEG · ECoG · MEG · fNIRS · fMRI · EMG · EOG · PSG.