I am in awe of all Florentine bus drivers. With unfaltering nonchalance, they maneuver massive vehicles through cobblestone streets the width of alleyways, whip around corners with centimeters of clearance, and narrowly avoid collisions with a constant barrage of nuns on bicycles and bewildered tourists. Like a medieval knight's sword, the bus seems an extension of its driver's body and mind.
How can humans get so good at driving? And how can chefs be so fast at chopping, and baseball players so good at swinging bats at exactly the right millisecond?
Yet again, kudos are owed to the human brain. Recent research shows that within a matter of minutes of operating a tool, your brain starts to integrate it into its map of your body. The tool actually does become an extension of your body, according to your mind. You become spatially attuned to the tool as if it were a new limb.
French neuro-psychologist Lucilla Cardinali has conducted a series of experiments investigating how tools affect the way we move. After getting used to picking up objects with a claw at the end of a rod, her test subjects spent several minutes readjusting to the normal lengths of their arms. This showed that the claw tool had been temporarily integrated into the brain's perception of arm length.
In one experiment Cardinali asked each test subject to point his or her finger directly above various positions, first with the claw tool then without. Going back to using their normal arms after using the tool, subjects greatly overestimated the lengths of their arms, bending their elbows in such a way that their index fingers hovered far short of their sought positions.
We've been using tools for so long that our brains have learned to integrate them without a (conscious) thought. And like always, practice - enough swings of a bat, or swerves of a bus - makes perfect.