Related Experiment Video
Updated: Mar 15, 2026

fMRI Validation of fNIRS Measurements During a Naturalistic Task
Published on: June 15, 2015
Noise contributions to the fMRI signal: An overview
1Center for Functional MRI, University of California San Diego, 9500 Gilman Drive MC 0677, La Jolla, CA 92093, United States; Departments of Radiology, Psychiatry and Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States.
Abstract:
The ability to discriminate signal from noise plays a key role in the analysis and interpretation of functional magnetic resonance imaging (fMRI) measures of brain activity. Over the past two decades, a number of major sources of noise have been identified, including system-related instabilities, subject motion, and physiological fluctuations. This article reviews the characteristics of the various noise sources as well as the mechanisms through which they affect the fMRI signal. Approaches for distinguishing signal from noise and the associated challenges are also reviewed. These challenges reflect the fact that some noise sources, such as respiratory activity, are generated by the same underlying brain networks that give rise to functional signals that are of interest.
Related Concept Videos
NMR Spectrometers: Overview
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
NMR Spectrometers: Resolution and Error Correction
Magnetic Resonance Imaging
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
¹H NMR Signal Integration: Overview

