2-Minute Neuroscience: Functional Magnetic Resonance Imaging (fMRI)

How fMRI Works00:00:07

Functional magnetic resonance imaging (fMRI) captures brain activity by exposing the brain to magnetic fields. These fields cause hydrogen protons to emit signals, allowing the scanner to reconstruct high-resolution images of brain tissue.

BOLD Contrast and Neural Activity00:00:39

The scanner uses blood-oxygen-level-dependent (BOLD) contrast to track oxygenated blood. Since active brain regions receive more oxygenated blood, researchers use color-coded images to map neural activity during specific tasks.

History and Current Challenges00:01:31

Developed in the early 1990s, fMRI is a widely used tool. However, the field has faced criticism due to small sample sizes, high rates of false positives, and limited independent reproducibility, prompting researchers to refine their methodologies.