Pay attention: Practice can make your brain better at focusing
Practicing paying attention can boost performance on a
new task, and change the way the brain processes information, a new
study says. This might explain why learning a new skill can start out
feeling grueling, but eventually becomes more natural — although right
now, the study’s findings are limited to a simple pattern-recognition
game.
There’s a long-standing debate about how exactly paying
attention helps us learn. One theory is that focusing makes the critical
piece of information stand out. If you imagine trying to pick out a
single instrument in an orchestra, that would be like turning up the
volume on the violin to make it easier to hear. Another theory is that
focusing actually dampens the background noise, like turning down the
volume on the rest of the instruments to make the violin clearer.
The question is: which part of this attention equation is
more important for learning, and how is it affected by practice? To
find out, researchers led by Sirawaj Itthipuripat
at the University of California, San Diego, subjected 12 research
participants to the least entertaining computer game in the world, while
measuring their brain activity. They found that the research subjects’
brains amped up activity in the visual processing center of the brain
(called the visual cortex) while they were learning how to play — kind
of like turning up the volume on that violin.
But as the research participants became more comfortable
with the game, and their scores stopped improving, that initial burst
quieted down. The researchers suspect that this more automatic phase is
the result of the brain fine-tuning what exactly it needs to pay
attention to, basically switching over to a process that’s more like
muting the volume on the rest of the orchestra. Both of these processes
are important for learning, just at different phases of training,
according to a study published Tuesday in the journal PLOS Biology.
Here’s how the study worked: over the course of a month,
study subjects (there were originally 23 undergraduate students, but 11
dropped out) repeatedly visited the lab and had little electrodes stuck
to their scalps. These allowed the researchers to measure the electrical
activity in the visual processing center of the students’ brains, using
a technique called electroencephalography, or EEG.
Then, the participants were asked to stare at a computer
screen as two black-and-white-striped circles briefly appeared and
disappeared, twice. They had to pick which of those flashes contained
the circle with the most contrast between its black-and-white stripes.
For some of the sessions, the students were told where the
contrast-boosted circle might appear, and to pay attention to that spot.
In others, they had to split their attention across both halves of the
screen.
If the setup sounds confusing, that’s because it is. But
there’s a point to it: our visual systems are finely tuned to detect
changes in contrast. (It’s actually how certain optical illusions
play tricks on our brains.) So asking the participants to evaluate
these striped circular patches let the researchers pair their
performance on the task with what was going on in their brains.
Turns out, the students got much better at
picking out the correct, contrast-boosted circle after two or three days
of training when they knew which part of the screen to pay attention
to. After that, they reached a level where they didn’t improve anymore —
but they were better than when they started. That matched the EEG
readouts, which showed an increase in their brains’ electrical activity
during the first few days of training. But that spike faded as their
performance on the task plateaued.
Itthipuripat suspects that this initial spike in activity
accounts for the early gains in performance, when the brain is learning
what to pay attention to. Then as the task becomes more natural,
another mechanism takes over that refines the pattern of brain activity
that drives the task, cutting down on the neural background noise.
Itthipuripat’s computer modeling supports this hypothesis, but more
research will need to be done to confirm whether that’s really what’s
going on.
These findings — especially in people — represent a significant advance, says Vincent Ferrera,
a neuroscientist at Columbia University’s Zuckerman Institute who was
not involved in the research. While neither he nor the study’s lead
author, Itthipuripat, are comfortable generalizing the results beyond
this simple visual task, they do provide a good reason to pay attention,
and to keep practicing. “It suggests that there is a benefit to
long-term training even after you stop seeing immediate changes,”
Ferrera says. “The brain is still figuring out ways to make itself
better.”
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