Blood-oxygen-level-dependent (BOLD) signal is like a special message your brain sends when it's working hard.
Imagine you're playing hide and seek. When you're hiding, you hold your breath to stay quiet, but when you’re ready to jump out and surprise someone, you take a big breath in. Your body needs more oxygen then, so your heart pumps harder, sending more oxygen-rich blood to your brain.
In the same way, when parts of your brain are busy thinking or remembering, they need more oxygen too. The BOLD signal is like a signal that shows which parts of the brain are working hard, it happens because the blood in those areas has more oxygen, and we can see that with special machines.
How It Works
Your brain uses blood to get oxygen, just like your body does. When you're thinking or solving a puzzle, certain parts of your brain light up, not literally, but they become more active. This means more blood flows there, and the blood has more oxygen, which is why we call it BOLD.
It's kind of like when you run around outside and then take deep breaths, your body sends more oxygen to your muscles so you can keep going. Your brain does something similar, but instead of muscles, it’s your thoughts that are getting a boost!
Examples
- A person is asked to solve math problems while in an MRI machine, and the scanner detects areas of the brain that become more active.
- The BOLD signal works by tracking how much blood flows to different parts of the brain during activity.
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See also
- What is Functional magnetic resonance imaging (fMRI)?
- Understanding MRI: What is functional MRI (fMRI)?
- Who is Neural Profiling?
- What is FMRI?
- Could We Upload Our Consciousness To A Computer?