Magnetoencephalography (MEG) brain scan results. A researcher pointing out areas of magnetic activity in a MEG brain scan. MEG is a functional neuroimaging technique which maps brain activity by recording magnetic fields produced by the electrical currents naturally occurring in the brain. They typically use highly sensitive SQUIDs (Superconducting Quantum Interference Devices) to detect the extremely small magnetic fields and associated gradients generated by neural activity in different parts of the brain. The resulting data may be used to investigate psychiatric and neurological disorders such as ADHD, epilepsy and age-related memory and cognitive syndromes such as Alzheimer's disease and dementia. Photographed at the National Intrepid Center of Excellence (NICoE) at the Walter Reed National Military Medical Center, Bethesda, Maryland, USA, on 16 March 2017.