BOLD signal

The BOLD signal, or Blood Oxygen Level Dependent signal, is a measurement used in functional MRI (fMRI) scans to observe brain activity. When a brain region becomes active, it consumes more oxygen. The body's response is to increase blood flow to that area, enhancing the oxygen supply. The BOLD signal detects this change in blood oxygen levels to indicate which parts of the brain are working harder. By analyzing these signals, researchers can map brain functions and understand how different areas contribute to thoughts, feelings, and behaviors.