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June 23, 2009

Removable Body Parts

We, as humans, use a myriad of tools throughout each day. Toothbrushes, cell phones, brooms, computers, silverware... the list is almost endless. These tools make our daily life a lot easier. They also seem easy to use. It requires almost no conscious thought to brush your teeth, for instance. It's like the tools become part of a person's body while in use.

According to a new study, that's exactly what happens.

Our brains have a concept of our bodies, known as a "body schema." When we use a tool, it is incorporated into that schema. The idea is centuries old. The methods for testing it are relatively new. A team of scientists in France reasoned that, if a person uses a tool, then their behavior performing a task immediately after using the tool should be different. To test this, they had test individuals use a mechanical grabber to extend their reach. Immediately afterward, the individuals continued to act like their arm was longer.

This new evidence helps explain why humans employ tools to the extent that we do. We're wired for it. Our brains quickly adapt to the capabilities a tool provides, and adds that tool on as a temporary body part. Thus, we are able to manipulate a tool just as well as we can manipulate our own hands.

Credit: Science Daily