BOLD (Blood Oxygen Level Dependent) signal

The BOLD (Blood Oxygen Level Dependent) signal is a way scientists measure brain activity using MRI scans. When a brain area becomes active, it consumes more oxygen. The body responds by increasing blood flow to that region, bringing in oxygen-rich blood. This change alters the magnetic properties of blood and surrounding tissue, which MRI can detect. The BOLD signal captures these shifts, allowing researchers to see which parts of the brain are active during specific tasks or thoughts. Essentially, it’s a non-invasive method to visualize brain function based on blood oxygen changes.