Have you ever lost your smartphone or been unable to access the Internet, and felt like a critical part of yourself was missing? That’s a sign that an external tool has become an extension of your mind. In a 2004 study, Angelo Maravita and Atsushi Iriki discovered that when monkeys and humans consistently use a tool to extend their reach, such as using a rake to reach an object, certain neural networks in the brain change their “map” of the body to include the new tool. This fascinating finding reinforces the idea that external tools can and often do become a natural extension of our minds.
