What type of activity does MEG primarily detect within the brain?

Magnetoencephalography (MEG) is a neuroimaging technique that primarily detects changes in the magnetic fields produced by the electrical activity of neurons in the brain. When neurons fire, they generate small magnetic fields, which can be measured with high precision. MEG is particularly useful for understanding the timing and localization of brain activity, making it a powerful tool in both clinical and research settings.

The detection of magnetic field changes provides unique insights into brain functioning, as it allows for real-time tracking of neural processing. This capability is distinct from other methods that monitor electrical potential changes or blood flow, as MEG specifically focuses on the magnetic domains associated with neuronal activity rather than the byproducts of that activity.

Understanding the nature of what MEG measures is crucial for distinguishing it from techniques such as electroencephalography (EEG), which primarily detects electrical potentials, and functional magnetic resonance imaging (fMRI), which examines blood flow alterations. Engaging with the magnetic fields generated during neural activity reveals intricate details about brain dynamics that are critical for both diagnosing neurological conditions and conducting cognitive neuroscience research.