Answer:
EEG or electroencephalography
Step-by-step explanation:
Electroencephalography or EEG is a technique to measure all the brain waves. These waves are occurred due to emotion, stress, or any change in stimuli received by the brain.
This is a technique where small metals are used to attach in the brain and detects the brain electrons wave. By using this technique individuals mental disorders like epilepsy and sleep disorders can be detected.
EEG measures the electrical activity of the brain. It also detects the activity of a large group of neurons.
Music therapy is also used with EEG to detect the anxiety, depression, of a person. As music induces strong emotions in a person, EEG is detected with music therapy.
But there are some limitations in this technique - it only detects the changes in the brain waves in the cortex, as the metals are attached to the skull. It can not measure deeper brain waves.
EEG also can't tell the exact location, where the brain wave changes. Because in a single time, it records several neuronal waves.
Besides these limitations, EEG is a useful technique to detect mental disorders.