Dr. Todorov has studied how we use our muscles, and here, too, he finds evidence of optimization at play. He points out that our body movements are “nonrepeatable”: we may make the same motion over and over, but we do it slightly differently every time.
“You might say, well, the human body is sloppy,” he said, “but no, we’re better designed than any robot.”
In making a given motion, the brain focuses on the essential elements of the task, and ignores noise and fluctuations en route to success. If you’re trying to turn on a light switch, who cares if the elbow is down or to the side, or your wrist wobbles — so long as your finger reaches the targeted switch?
Dr. Todorov and his coworkers have modeled different motions and determined that the best approach is the wobbly, ever-varying one. If you try to correct every minor fluctuation, he explained, not only do you expend more energy unnecessarily, and not only do you end up fatiguing your muscles more quickly, you also introduce more noise into the system, amplifying the fluctuations until the entire effort is compromised.
“So we reach the counterintuitive conclusion,” he said, “that the optimal way to control movement allows a certain amount of fluctuation and noise” — a certain lack of control.
Posts
No comments:
Post a Comment