Answer:
EEG
Explanation:
EEG or electroencephalography is a technique that measures the electrical activity of brain.
For measuring electrical activity, electrodes are attached to her scalp. An abnormal activity of brain such as epilepsy can also be recorded by EEG.
The brain is an electrical system as it is a network of neurons. Neurons communicate with each other via electrical signal. The more electrical signals corresponds to more brain activity.
The electrodes of an EEG record the electrical changes occurring in thousands of neurons.
The signal received by the electrodes is amplified by an amplifier. Various maps of brain activity is generated by a computer.