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Wednesday, November 25, 2015

A Peek At Brain Connections May Reveal Attention Deficits

From NPR's WBUR 90.9 FM

By Jon Hamilton
November 23, 2015

A look at the brain's wiring can often reveal whether a person has trouble staying focused, and even whether he or she has attention deficit hyperactivity disorder, known as ADHD. 

Brain imaging experiments found patterns associated
with attention span. (iStockphoto)

A team led by researchers at Yale University reports that they were able to identify many children and adolescents with ADHD by studying data on the strength of certain connections in their brains.

"There's an intrinsic signature," says Monica Rosenberg, a graduate student and lead author of the study in Nature Neuroscience. But the approach isn't ready for use as a diagnostic tool yet, she says.

The finding adds to the evidence that people with ADHD have a true brain disorder, not just a behavioral problem, says Mark Mahone, director of neuropsychology at the Kennedy Krieger Institute in Baltimore. "There are measurable ways that their brains are different," he says.

Listen to this story (3:26) HERE.

The latest finding came from an effort to learn more about brain connections associated with attention.

Initially, the Yale team used functional MRI, a form of magnetic resonance imaging, to monitor the brains of 25 typical people while they did something really boring. Their task was to watch a screen that showed black-and-white images of cities or mountains and press a button only when they saw a city.

"It gets really dull after a while," Rosenberg says, "so it's really hard to pay attention to over a long period of time."

During the test, the team measured the strength of thousands of connections throughout the participants' brains. And they were able to identify certain patterns that predicted a person's ability to stay focused.

What's more, these connection patterns were present even when the person wasn't trying to keep track of cities and mountains, or anything else, Rosenberg says. "We could actually look at that signature while they were resting and we could still predict their attention," she says.

The team wanted to know whether this signature could be used to assess younger people, especially those with ADHD. So they reviewed data on 113 children and adolescents whose brains had been scanned by scientists in China as part of an unrelated study. The children had also been assessed for ADHD.

The team used the information about brain connections to predict how well each child would do on the attention task with cities and mountains.

"And what we found was really surprising, and I think really cool," Rosenberg says. "When we predicted that a child would do really well on the task, they had a low ADHD score. And when we predicted they would do really poorly on the task, they had a high ADHD score, indicating that they had a severe attention deficit."

For many of the children, the researchers were able to predict not only whether they had ADHD, but how severe the problem was.

The test isn't perfect but does provide useful information, Rosenberg says. Eventually, she says, it might help psychologists and psychiatrists assess children with attention problems.

One potential limitation of the approach is that attention deficits aren't found only in people with ADHD, says Mahone. Individuals with anxiety, depression, learning disabilities and autism also have trouble staying focused, he says.

Regardless of the diagnosis, though, Mahone says, "knowing how the brain is different in a disorder, we can look at ways to help 'normalize' the brain."

Transcript

ARI SHAPIRO, HOST: There's new evidence that people with ADHD, or attention deficit hyperactivity disorder, have brains that are wired differently. NPR's Jon Hamilton reports on a test that measures how different that wiring is. And the test might even help predict a person's ability to stay focused.

JON HAMILTON, BYLINE: A team at Yale University wanted to know more about the brain circuits that affect attention. So they used a type of brain scan called functional MRI to monitor the brains of 25 typical people doing something really boring. The participants reclined in a scanning tunnel, watching a screen. Monica Rosenberg, one of the study's authors, says they saw images of cities or mountains.

MONICA ROSENBERG: And their job was to just press a button that they had every time they saw a city and not to press anything when they saw a mountain.

HAMILTON: Again and again and again for half an hour.

ROSENBERG: It gets really dull after a while. And the images fade into each other. So it sounds simple, but it's really hard to pay attention to over a long period of time.

HAMILTON: During the test, the team measured the strength of thousands of connections in the participants' brains. And the scientists were able to identify certain patterns that predicted a person's ability to stay focused. What's more, Rosenberg says, these connection patterns were present even when the person wasn't trying to keep track of cities or mountains or anything else.

ROSENBERG: We could actually look at that signature while they were resting, so while they weren't doing anything at all, and we could still predict their attention. So there was some kind of, like, intrinsic signature.

HAMILTON: At least for the 25 typical adults in the study, but the team wanted to know whether this signature would apply to younger people, especially those with ADHD. So they reviewed data on 113 children and adolescents whose brains had been scanned by scientists in China as part of an unrelated study. The children had also been assessed for ADHD.

Without knowing which kids had attention problems, Rosenberg's team relied on their brain scans to predict how well or poorly each kid could do on the attention task.

ROSENBERG: And what we found was really surprising and I think really cool, which is that when we predicted that a child would do really well on the task, they actually had a low ADHD score. And when we predicted they would do really poorly on the task, they had a high ADHD score, indicating that they have a severe attention deficit.

HAMILTON: For many of the children, the researchers were able to predict not only whether they had ADHD but how severe the problem was. Even so, Rosenberg says, the approach isn't perfect.

ROSENBERG: I wouldn't say this tells you everything. I wouldn't base a clinical diagnosis just on this scan.

HAMILTON: But she says it does provide useful information. Mark Mahone, a neuropsychologist at the Kennedy Krieger Institute in Baltimore, says the results offer one more piece of evidence that ADHD is a brain disorder, not just a behavior problem.

MARK MAHONE: I think it shows us that there are measurable ways that individuals who have been carefully diagnosed with ADHD - there are measurable ways that their brains are different.

HAMILTON: Mahone says the brain differences found by the Yale researchers may also appear in people with other disorders.

MAHONE: Deficits in sustained attention are in no way unique to ADHD. You know, individuals with anxiety may have some of these problems, depression, learning disabilities of one type or another, autism.

HAMILTON: Mahone says regardless of the diagnosis, treatments need to focus on the specific deficits a person has.

MAHONE: Knowing how the brain is different in a disorder, we can look at ways to help, quote, unquote, "normalize" the brain.

HAMILTON: And tests like the one developed at Yale should help assess the result. The new research appears in the journal Nature Neuroscience.

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