How the brain sees follow-through

The windup before the pitch. The take-away before the golf swing. When you learn to pitch a softball, swing a golf club or shoot a basketball, you learn that preparation is important. You also learn about follow-through — the upswing of the golf club or the bend in the elbow after a softball pitch.

It’s the preparation and the execution that get the ball across the plate, so why should we care about follow-through? In theory, once the ball has left your hands or sailed away from your club or racket, there’s no movement you could make that could affect what happens next. So while some follow-through might be important to diffuse the energy you just put into your shot, it shouldn’t really matter whether you swing your golf club up in an arc, whip it off to the side or club your opponent over the head with it.

But follow-through is in fact quite important, and not just as an extension of the movements that preceded it. Consistent follow-through actually helps performance, reports neuroscientist Ian Howard and colleagues at the University of Plymouth in England. The finding gives coaches some science to back up their training, and helps scientists understand how the brain accesses motor memories. 

Howard has always been interested in how the brain learns movement tasks. “The first study we did looked at the preparation movement — you move backwards and then you move forwards [as in a golf swing],” he says. His lab found that the preparation before a particular motion had a strong effect on how our brains learn and recall motor movements.

This time, the scientists wanted to look at how the brain perceives follow-through. To test this, they had 46 right-handed people operate a robotic arm with a joystick while they viewed a simulated task on a monitor. In the first experiment, the volunteers had to make a reaching movement toward a central dot. They were also given another target farther away, at an angle to the left or right.  Half of the participants were instructed to perform a follow-through — move past the first dot toward the second. The other half were presented with the dot, but told to stop at the first dot — no follow-through allowed.

To make the task more challenging, the volunteers pushed forward toward the first dot while another machine produced a force field to shove the robotic arm off-course. The faster the participants pushed forward, the harder the machine worked to push them away to the side. The direction of the force field matched the placement of the follow-through dot. If it was on the right, the force field pushed from the right, so the volunteers knew from the placement of the follow-through dot how to plan their movements. The force field let up past the first dot so the follow-through was unimpeded.

The participants who made the follow-through movement had an easier time learning to compensate for the force field. But the follow-through had to be consistent. In a second task, participants made either a single follow-through movement to a single point, or made many different follow-through movements to different points. Those with only one follow-through option mastered the task much faster. Howard and his colleagues published the findings January 8 in Current Biology.

The results show that our brains don’t perceive preparation, swing and follow-through as separate movements. Instead, these motions are a single motor memory.

This means that consistent follow-through is important for performance. “If you’ve got consistent follow-through in one motor memory, you’ve got to learn one task, but if you have nine follow-throughs you have to learn nine tasks.” Howard explains. “If you have only one task to learn, you learn it faster.” Practicing a golf swing with nine different follow-throughs makes the brain access nine different motor memories. And if you’re accessing many different motor memories, you will master the task more slowly than if you just practice and access one single, well-honed motion.

“It’s an elegant example of how to use just behavioral tasks to get at something deep and interesting,” says Mark Churchland, a neuroscientist at Columbia University in New York City. The next step, he says, is to do experiments with animals learning tasks while researchers study the animals’ brains in real time.

Of course, inconsistent follow-through did not prevent participants from learning the task. It merely slowed them down. But it’s a good case for practicing consistent follow-through movements when learning a task. We could all use a few tips to improve our golf swing.