How We Learn (22 page)

Our faith in repetition never leaves us, not entirely. I sometimes think—if only I could channel my childlike devotion today when
trying to learn something new. I’d channel it into the piano, or genetics, or mechanics. I’d practice like a machine, one skill at a time, until each one was automatic, driven deep into the marrow. Play Elgar, save some lives, fix the car when it broke down. At some level, I sort of believe it could still happen, given enough time. Some psychologists and writers have even tried to quantify that time. The path to exceptional performance, they argue, is through practice: ten thousand hours of it, to be exact. The gist of that rule is hard to resist, even if the number itself is arbitrary, because we read it in terms of
repetition
, as well as quantity. As the common exhortation goes:
Don’t practice until you get it right. Practice until you can’t get it wrong
.

Then I remember. I remember what happened in my own life when I did put in the time.

I was Mr. Repetition as a kid. As a student, as a music student, as an athlete. I was the one who did three hundred ollies in an afternoon, never quite getting it right. There I was, scraping up the driveway, only to look up and see some kid who didn’t have anywhere near my determination roll by, popping clean jumps without even thinking about it. Same for the behind-the-back dribble, the guitar solo, the inside-skate stop in hockey. I wanted it so bad, I’d throw myself into practicing but somehow never got
good
—while other kids who weren’t putting in nearly the same amount of dedicated time picked up the skills without seeming to sweat the details. Were they just …
naturals
? Did they have private teachers? Secret handshakes? I had no idea. I blamed my own lack of native gifts and kept looking for something that would come easily. What I never did was stop to ask whether my approach to practice was, in fact, the right one.

Nor did anyone else, at least not back in the early 1970s. At that time, scientists thought about practice in the same way we all did: the more, the better. To put it in precise terms, psychologists argued that any variation in the practice schedule that makes the target skill—whether in skating, algebra, or grammar—more immediate, more frequent, and more accurate improves learning. Brute-force repetition
does that, and everyone who truly masters a skill has done at least some of it, usually lots. That’s the part they tend to remember later on, too—the repetition—and not other innovations or alterations they might have incorporated along the way.

One of the first hints that there might be another way came in a 1978 experiment by a pair of researchers at the
University of Ottawa. Robert Kerr and Bernard Booth were trained in kinetics, the study of human movement. Kineticists often work closely with trainers and coaches, and they’re interested in the factors that contribute to athletic ability, injury recovery, and endurance. In this case, Kerr and Booth wanted to know how two distinct kinds of practice affected a simple, if somewhat obscure, skill: beanbag tossing. (It was an inspired choice, as it turned out; it’s a skill that most of us have tried, at a kid’s birthday party or some amusement park game, but that no one works on at home.) They recruited thirty-six eight-year-olds who were enrolled in a twelve-week Saturday morning PE course at a local gym and split them into two groups. The researchers ran both groups through a warm-up session of target practice to get the kids used to the game—and an awkward game it was, too. The children were asked to toss small golf-ball-sized beanbags from a kneeling position at bull’s-eyes on the floor. But they did so while wearing a harness that held a screen blocking their eyes. They took each shot blindly, removed the screen to see where it landed—
then
took the next shot.

On an initial trial, the two groups scored equally well, displaying no discernible difference in skill level.

Then they began regular practice sessions. Each child had six practice sessions, taking twenty-four shots every time. One group practiced on one target, a bull’s-eye that was just three feet away. The other group practiced on two targets, one that was two feet away and another that was four feet away, alternating their shots. That was the only difference.

At the end of the twelve-week course, the researchers gave the
children a final test on performance—but only on the three-foot target. This seems unfair. One group was practicing on the three-foot target the whole time, and the other not at all. The group that practiced at three feet should have had a clear advantage. Yet it didn’t turn out that way. The kids in the mixed-target group won this competition, and handily. Their average distance away from the (three-foot) target was much smaller than their peers on the final test. What was going on? Kerr and Booth ran the same experiment again in twelve-year-olds, just to make sure the finding held up. It did. Not only that, but the result was even more dramatic in the older kids. Was it luck? Did the better groups have a few ringers? Not at all, reported Kerr and Booth. “A varied practice schedule may facilitate the initial formation of motor schema,” they wrote, the variation working to “
enhance movement awareness.” In other words: Varied practice is more effective than the focused kind, because it forces us to internalize general rules of motor adjustment that apply to
any
hittable target.

A big idea—if true.

It might have been a fluke, given the strangeness of the task: blind beanbag tossing. Not that it mattered at the time, in part because no one was paying attention. The beanbag experiment was as obscure as they come. (So much so that it disappeared entirely from the website of the journal in which it originally appeared,
Perceptual and Motor Skills;
it took editors weeks to find it when I asked.) Yet even if the study had made the nightly news, it’s not likely to have changed many minds, certainly not among the academics studying memory. Kinetics and cognitive psychology are worlds apart in culture and in status. One is closer to brain science, the other to gym class. A beanbag study with a bunch of eight-year-olds and twelve-year-olds wasn’t about to alter centuries of assumptions about how the brain acquires new skills. At least not right away.

• • •

Psychologists who study learning tend to fall into one of two camps: the motor/movement, or the verbal/academic. The former focuses on how the brain sees, hears, feels, develops reflexes, and acquires more advanced physical abilities, like playing sports or an instrument. The latter investigates conceptual learning of various kinds: language, abstract ideas, and problem solving. Each camp has its own vocabulary, its own experimental paradigms, its own set of theories. In college, they are often taught separately, in different courses: “Motor and Perceptual Skills” and “Cognition and Memory.”

This distinction is not an arbitrary one. Before we go any further, let’s revisit, briefly, the story of Henry Molaison, the Hartford man whose 1953 surgery for epilepsy severely damaged his ability to form new memories. After the surgery, Molaison’s brain could not hold on to any describable memories, such as names, faces, facts, and personal experiences. The surgeon had removed the hippocampus from both hemispheres of his brain; without those, Molaison could not move short-term memories into long-term storage. He could, however, form new motor memories. In one of the experiments described in
chapter 1
, Molaison learned to trace a star while watching his drawing hand in a mirror. He became more and more adept at this skill over time, even though he had no memory of ever practicing it.

A major implication of the Molaison studies was that the brain must have at least two biological systems for handling memory. One, for declarative memories, is dependent on a functioning hippocampus. The other, for motor memories, is based in different brain organs; no hippocampus required. The two systems are biologically distinct, so it stood to reason that they’re functionally distinct, too, in how they develop, strengthen, and fade. Picking up Spanish is not the same as picking up Spanish guitar, and so psychology has a separate tradition to characterize each.

In the early 1990s, a pair of colleagues at UCLA decided to try something radical: They would combine the two traditions—motor and verbal—into a single graduate seminar, which they called “Principles
of Motor and Verbal Learning.” The two researchers—Richard A. Schmidt, a motor-learning specialist, and the ever-present Robert Bjork, a verbal-learning expert—thought students would gain a better understanding of the main distinctions between their respective fields and how each type of learning is best taught. “Dick and I just assumed we’d lay out what the differences were between motor and verbal, nothing more than that,” Bjork told me. “But as we got deeper into it, the whole project changed course.”

An odd signal echoed down through the literature, they saw. For starters, they stumbled upon the neglected beanbag study, and took its conclusions at face value, as valid. They then searched the literature to see if they could find other studies in which mixed or interrupted practice sessions led to better performance over time than focused ones. If the beanbag result was solid, and Kerr and Booth were correct in arguing that it revealed a general principle of learning, then it should show up in other experiments comparing different practice techniques.

And so it did, in papers by researchers who weren’t familiar with Kerr and Booth’s work at all. In 1986, for instance, researchers at Louisiana State University tested how well thirty young women learned three
common badminton serves. The short serve, the long, and the drive each has a distinct trajectory and takes some practice to hit well. To make a short serve, the player has to hit the shuttlecock just over the net (no more than fifty centimeters, or a foot and a half) so that it lands in the front third of the opposing court. A long serve passes at least two and half meters (about eight feet) above the net and lands in the back third of the opposite court. A drive splits the difference and darts downward to the midline on the other side. The researchers—Sinah Goode and Richard Magill—judged the serves by two criteria: where they landed and where they passed over the net. They split the women into three groups of ten, each of which practiced according to the same schedule, for three days a week over three weeks, thirty-six serves at a time. The sessions themselves were
different, however. Group A performed
blocked
practice, rehearsing only one type of serve per session: doing thirty-six short ones on one day, for instance, thirty-six long ones the next session, and thirty-six drives the next. Group B performed
serial
practice, trying the serves in a given order—short, then long, then drive—repeatedly. Group C practiced randomly, trying any serve they wanted but no more than two of the same ones in a row.

By the end of the three weeks, each participant had practiced each serve the same number of times, give or take a few for those in the random group.

Goode and Magill wanted not only to compare the relative effectiveness of each type of practice schedule. They also wanted to measure how well the participants’ skills
transferred
to a new condition. Transfer is what learning is all about, really. It’s the ability to extract the essence of a skill or a formula or word problem and apply it in another context, to another problem that may not look the same, at least superficially. If you’ve truly mastered a skill, you “carry it with you,” so to speak. Goode and Magill measured transfer in a subtle, clever way. On their final test of skill, they made one small adjustment: The participants served from the left side of the court, even though they’d practiced only on the right. During the test, the examiner called out one skill after another: “Hit me a drive … Okay, now a short serve … Now give me a long one.” Each participant hit each serve the same number of times on the final test—six—though never two of the same kind in a row. Goode and Magill then rated each serve, according to its arc and placement, on a scale from 0 to 24.

The winner? Team Random, by a long shot. It scored an average of 18, followed by the serial group, at 14. The blocked practicers, who’d focused on one serve at a time, did the worst, with an average of 12—and this despite having appeared, for most of the three weeks, to be improving the most. They were leading the pack going into Week 3, but come game time, they collapsed.

The authors weren’t entirely sure what caused such a dramatic
reversal. Yet they had a hunch. Interfering with concentrated or repetitive practice forces people to make continual adjustments, they reasoned, building a general dexterity that, in turn, sharpens each specific skill. Which, by the way, is exactly what the beanbag study concluded. But Goode and Magill then took it one step further. All that adjusting during a mixed-practice session, they wrote, also enhances transfer. Not only is each skill sharper; it’s performed well regardless of context, whether indoors or out, from the right side of the court or the left. “The general goal of practice is to transfer to a game,” the pair concluded. “A game situation varies from event to event, making random testing the best condition to
appraise the effectiveness of practice.”

Schmidt and Bjork knew that this experiment, like the beanbag toss, proved nothing on its own; it was just one study. But there was a scattering of still others—of keyboard ability, of videogame skills, of precise arm movements—and they all had one thing in common: Whenever researchers scrambled practice sessions, in one form or another, people improved more over time than if their practice was focused and uninterrupted.

One way to think about this is in terms of practice versus performance. During practice we have a measure of control. We can block out or avoid distractions, we can slow down if needed, and most important, we decide which skill or move or formula we want to rehearse
before
actually doing it. We’re in charge. Performance is another story. Growing up, all of us knew kids who were exceptional in practice but only mediocre come game time. And vice versa, kids who looked awkward in drills and then came alive when it mattered, during competition, or performing in front of an audience. You can practice the step-over soccer move a thousand times in your front yard, but doing it at full speed with two opposing players running at you is much harder. It’s no longer a single move anymore, practiced in isolation, but one step in an ever-changing, fast-paced dance.