How We Learn (32 page)

Q:
Is cramming a bad idea?

A
: Not always. Cramming works fine as a last resort, a way to ramp up fast for an exam if you’re behind and have no choice. It’s a time-tested solution, after all. The downside is that, after the test, you won’t remember a whole lot of what you “learned”—if you remember any at all. The reason is that the brain can sharpen a memory only after some forgetting has occurred. In this way, memory is like a muscle: A little “breakdown” allows it to subsequently build greater strength. Cramming, by definition, prevents this from happening.

Spaced rehearsal or study (see previous question) or self-examination (see next question) are far more effective ways to prepare. You’ll remember the material longer and be able to carry it into the next course or semester easily. Studies find that people remember up to twice as much of material that they rehearsed in spaced or tested sessions than during cramming. If you must cram, do so in courses that are not central to your main area of focus.

Q:
How much does quizzing oneself, like with flashcards, help?

A
: A lot, actually. Self-testing is one of the strongest study techniques there is. Old-fashioned flashcards work fine; so does a friend, work colleague, or classmate putting you through the paces. The best self-quizzes do two things: They force you to
choose
the right answer from several possibilities; and they give you immediate feedback, right or wrong. As laid out in
chapter 5
, self-examination improves retention and comprehension far more than an equal amount of review time. It can take many forms as well. Reciting a passage from memory, either in front of a colleague or the mirror, is a form of testing. So is explaining it to yourself while pacing the kitchen, or to a work colleague or friend over lunch. As teachers often say, “You don’t fully understand a topic until you have to teach it.” Exactly right.

Q:
How much does it help to review notes from a class or lesson?

A
: The answer depends on how the reviewing is done. Verbatim copying adds very little to the depth of your learning, and the same goes for looking over highlighted text or formulas. Both exercises are fairly passive, and can cause what learning scientists call a “fluency illusion”: the impression that, because something is self-evident in the moment, it will remain that way in a day, or a week. Not necessarily so. Just because you’ve marked something or rewritten it, digitally or on paper, doesn’t mean your brain has engaged the material more deeply. Studying highlighted notes and trying to write them out—without looking—works memory harder and is a much more effective approach to review. There’s an added benefit as well: It also shows you immediately what you don’t know and need to circle back and review.

Q:
There’s so much concern that social media and smart-phones and all manner of electronic gadgets are interfering with learning—and even changing the way people think. Is this merited? Is distraction always bad?

A
: No. Distraction is a hazard if you need continuous focus, like when listening to a lecture. But a short study break—five, ten, twenty minutes to check in on Facebook, respond to a few emails, check sports scores—is the most effective technique learning scientists know of to help you solve a problem when you’re stuck. Distracting yourself from the task at hand allows you to let go of mistaken assumptions, reexamine the clues in a new way, and come back fresh. If you’re motivated to solve the problem—whether it’s a proof, an integral, or a paragraph you just can’t get right—your brain will continue to work on it during the break
off-line
, subconsciously, without the (fixated, unproductive) guidance you’ve been giving it. The evidence on this is discussed in
chapter 6
.

Q:
Is there any effective strategy for improving performance on longer-term creative projects?

A
: Yes. Simply put:
Start
them as early as possible, and give yourself permission to walk away. Deliberate interruption is not the same as quitting. On the contrary, stopping work on a big, complicated presentation, term paper, or composition activates the project in your mind, and you’ll begin to see and hear all sorts of things in your daily life that are relevant. You’ll also be more tuned into what you
think
about those random, incoming clues. This is all fodder for your project—it’s interruption working in your favor—though you do need to return to the desk or drafting table before too long. The main elements in this “percolation” process are detailed in
chapter 7
.

Q:
What’s the most common reason for bombing a test after what felt like careful preparation?

A
: The illusion that you “knew” something well just because it seemed so self-evident at the time you studied it. This is what learning scientists call “fluency,” the assumption that because something is well known now it will remain that way. Fluency illusions form automatically and subconsciously. Beware study “aids” that can reinforce the illusion: highlighting or rewriting notes, working from a teacher’s outline,
re
studying after you’ve just studied. These are mostly passive exercises, and they enrich learning not at all. Making your memory work a little harder—by self-quizzing, for example, or spacing out study time—sharpens the imprint of what you know, and exposes fluency’s effects.

Q:
Is it best to practice one skill at a time until it becomes automatic, or to work on many things at once?

A
: Focusing on one skill at a time—a musical scale, free throws, the quadratic formula—leads quickly to noticeable, tangible improvement. But over time, such focused practice actually limits our development of each skill. Mixing or “interleaving” multiple skills in a practice session, by contrast, sharpens our grasp of all of them. This principle applies broadly to a range of skills, and can be incorporated into daily homework or practice—by doing a geometry proof from early in the term, for example, or playing arpeggios you learned years ago, or intermingling artistic styles in studying for an art history class. This kind of mixing not only acts as a review but also sharpens your discrimination skills, as described in
Chapter 8
. In a subject like math, this is enormously helpful. Mixed-problem sets—just adding one or two from earlier lessons—not only reminds you what you’ve learned but also trains you to
match
the problem types with the appropriate strategies.

For my parents
   

Acknowledgments

Writing a book is one part lonely effort and two parts group therapy, and I am forever grateful to those who provided the latter. To Kris Dahl, my exuberantly effective agent, and to Andy Ward, my editor, an exacting collaborator who forced me to think through the ideas in this book more clearly and deeply—the best company anyone could have. I owe a great debt to Barbara Strauch at
The New York Times
for years of support and advice, and my colleagues at the Science Times. I thank Rick Flaste for seeing (decades ago) that behavior was a beat worth covering and for bringing me to a great newspaper that continues to cover scientific research in depth.

My work has allowed me access to the many scientists who provided the bones of this book. Among them, I am grateful to Suzanne Corkin, Michael Gazzaniga, Daniel Willingham, Philip Kellman, Steven Smith, Doug Rohrer, Matt Walker, Henry Roediger III, Harry Bahrick, Ronda Leathers Dively, the great Todd Sacktor, and especially Robert and Elizabeth Ligon Bjork, who reviewed large portions of the manuscript and helped me understand the most difficult
pockets of the science. I am also in debt to the staff at Columbia University’s Social Work Library and the University of Colorado’s Library for Research Assistance. Any mistakes that remain in the text are all mine.

I leaned heavily on family and friends every step of the way: My parents, James and Catherine, and my sister, Rachel, who all provided big love and a place for me to hole up, pace, talk to myself, and write; my brothers, Simon and Noah; my daughters, Isabel and Flora, who helped me through tough spots; and my wife, Victoria, who provided editing and advice virtually every day. Special mention goes to my friends Mark Zaremba, who delivered the graphics, and to Tom Hicks and John Hastings, for listening to hours of arcane complaints about this project, even while splitting the bar tab.

Notes

Chapter One: The Story Maker

1
scents of daily life
For the general discussion of brain biology, I relied on two books: Eric R. Kandel, M.D.,
In Search of Memory
(New York: W.W. Norton & Company, 2006); and Larry R. Squire and Eric R. Kandel,
Memory from Mind to Molecules, second edition
(Greenwood Village, CO: Roberts & Company, 2009).

2
up its gray matter
Paul Reber, “What Is the Memory Capacity of the Human Brain?”
Scientific American
, May/June 2010.

3
awaiting surgery
Gelbard-Sagiv, Roy Mukamel, Michal Harel, Rafael Malach, and Itzhak Fried, “Internally Generated Reactivation of Single Neurons in Human Hippocampus During Free Recall,”
Science
322, 2008, 96–100.

4
named Henry Molaison
For my discussion of H.M., I relied on interviews with Brenda Milner and Suzanne Corkin as well as Corkin’s book
Permanent Present Tense
(New York: Basic Books, 2013).

5
drawing hand in a mirror
Squire and Kandel,
Memory from Mind to Molecules, second edition
.

6
one hemisphere at a time
For my discussion of split-brain work, I relied on interviews with Michael Gazzaniga and the following studies: M. S. Gazzaniga, “Forty-five years of split-brain research and still going strong,”
Nature Reviews Neuroscience
6, August 2005, 653–59; M. S. Gazzaniga, J. E. Bogen, and R. W. Sperry, “Dyspraxia following division of the cerebral commissures,”
Archives of Neurology
, Vol. 16, No. 6, June 1967, 606–612; M. S. Gazzaniga, J. E. Bogen, and R. W. Sperry, “Observations on visual perception after disconnexion of the cerebral hemispheres in man,”
Brain
, Vol. 88, Part 2, June 1965, 221–36; M. S. Gazzaniga, J. E. Bogen, and R. W. Sperry, “Some functional effects of sectioning the cerebral commissures in man,”
Proceedings of the National Academy of Sciences of the United States of America
, Vol. 48, No. 10, Oct. 1962, 1765–69.

7
only the shovel
For this I relied on an interview with Michael Gazzaniga, for his recollection of the experiment that triggered his conclusion.

Chapter Two: The Power of Forgetting

1
we remembered nothing
William James,
The Principles of Psychology, Volume I
(New York: Henry Holt and Company, 1890), 680.

2
and related ideas
Robert A. Bjork and Elizabeth Ligon Bjork, “A New Theory of Disuse and an Old Theory of Stimulus Fluctuation.” In A. Healy, S. Kossly, and R. Shiffrin, eds.,
From Learning Processes to Cognitive Processes: Essays in Honor of William K. Estes, Volume 2
(Hillsdale, NJ: Erlbaum, 1992), 35–67.

3
remains a mystery
David Shakow, “Hermann Ebbinghaus,”
The American Journal of Psychology
42, No. 4, Oct. 1930, 511.

4
working-class East End
Matthew Hugh Erdelyi,
The Recovery of
Unconscious Memories: Hypermnesia and Reminiscence
(Chicago: The University of Chicago Press, 1998), 11.