By placing electrodes on other parts of the body, the echoes of the heart's electrical activity can be detected.

This article claims that, by placing electrodes on the scalp and adding a little electricity, people can boost their memories:

The process consists in placing in a vacuum two leaves, or electrodes, of gold, and between them the original record.

To link brains and machines, researchers place electrodes directly into parts of the brain that produce motor plans.

From there, the surgeon threads a slender tube down into the brain to place electrodes on each side of a specific part of the brain.

In the late 1970's, researchers mostly placed sharp-tipped electrodes into single cells and measured firing patterns.

The researchers also placed electrodes on the heads of patients and found abnormal electrical activity in those areas of the brain.

Do not place electrodes on broken or irritated skin.

Iraqi engineers even managed to place electrodes in the waters.

Now, if someone were to probe the brain by placing electrodes in the primary visual cortex, they may find what appears to be random electrical activity.