Electrical Activity

A living brain and nervous system is made up of neurons which temporarily become electrically charged and when sufficient electrical potential is reached, signal other neurons, which in turn become electrically charged. The function of this network of neurons in a living creature is to regulate and govern various systems in the organism. When death occurs, it is always accompanied by a total failure of this system.4

Because brain and brain stem signals involve waves of neurons acting in concert, it's possible to detect the net electrical effect using Electroencephalography, or (EEG), which uses electrodes to detect electric potential. Since electrical signals in the nervous system are necessary to maintain a living organism, and since a sufficiently sensitive EEG can detect whether these signals are occurring, EEG can be used to confirm the arrival of death.5