When confronted with an overly active child, many exasperated teachers and parents respond the same way: “Sit still!” It might be more effective, though, to encourage the child to run. Recent research suggests that even small amounts of exercise enable children to improve their focus and academic performance.
By now it’s well known that diagnoses of attention deficit hyperactivity disorder are increasingly widespread among American children: The label has been applied to about 11 percent of those between the ages of 4 and 17, according to the latest federal statistics. Interestingly, past studies have shown a strong correlation between greater aerobic fitness and attentiveness. But these studies did not answer the question of which comes first, the fitness or the attentional control.
Addressing that mystery was a goal of a study published last year in The Journal of Pediatrics. Researchers at the University of Illinois at Urbana-Champaign recruited 40 8-to-10-year-old boys and girls, half of whom had A.D.H.D. They all took a series of computerized academic and attentional tests. Later, on one occasion they sat and read quietly for 20 minutes; on another, they walked briskly or jogged for 20 minutes on treadmills. After each task, the children wore caps containing electrodes that recorded electrical activity in the brain as they repeated the original tests.
The results should make administrators question the wisdom of cutting P.E. classes. While there were few measurable differences in any of the children’s scores after quiet reading, they all showed marked improvements in their math and reading comprehension scores after the exercise. More striking, the children with A.D.H.D. significantly increased their scores on a complicated test, one in which they had to focus on a single cartoon fish on-screen while other cartoon fish flashed on-screen to distract them. Brain-wave readings showed that after exercise, the children with A.D.H.D. were better able to regulate their behavior, which helped them pay attention. They responded more nimbly to mistakes like incorrect keystrokes. In short, the children with A.D.H.D. were better students academically after exercise. So were the students without A.D.H.D.
“In terms of a nonpharmacological means of dealing with attentional-control problems in children, exercise looks as if it could be quite beneficial,” says Charles Hillman, the professor of kinesiology at the University of Illinois who oversaw the study. “Especially since it seems to also improve the academic performance of children who don’t have attentional-control problems.”
What’s more, adds Matthew Pontifex, now an assistant professor at Michigan State University and the study’s lead author, “You don’t need treadmills.” Just get restless children to march or hop or in some fashion be physically active for a few minutes. Coax their peers to join in.
Of course, even as it reinforces the accumulating evidence that exercise is good for brains, this short-term study leaves many questions unanswered: How much and what kind of physical activity is optimal? Does it permanently lessen attentional problems? Does exercise directly affect attention at all? In their study, the researchers speculate that exercise might sharpen mental focus in part by increasing brain activity in the frontal lobe. But understanding its mechanisms may not be needed for teachers and parents to consider deploying movement to counter wandering attentions.
MRI shows disrupted connections in the brains of young people with ADHD
OAK BROOK, Ill. – A new study has found that children and adolescents with attention deficit hyperactivity disorder (ADHD) have disrupted connections between different areas of the brain that are evident on resting-state functional magnetic resonance imaging (rfMRI). The results of this research are published online in the journal Radiology.
The findings point to the potential of rfMRI to help provide objectively accurate, early diagnosis of a disorder that affects approximately 5 percent of children and adolescents worldwide.
ADHD is a disorder characterized by age-inappropriate degrees of inattention, hyperactivity and impulsivity. Functional MRI studies, which measure brain activity when a person is focused on a particular task, have implicated the brain's frontostriatal circuit, a collection of neural pathways in the frontal lobe of the brain that helps control behavior. However, the specific brain physiology underlying ADHD remains poorly understood.
For the new study, researchers used rfMRI, a relatively new technique that assesses neural function when the brain is not focused on a specific task. The technique is useful for exploring the brain's functional organization independent of task performance.
The researchers compared rfMRI results in 33 boys with ADHD, ages 6 to 16, with those of 32 similarly aged, healthy controls. They correlated the MRI findings with results from tests of executive function, a term for the set of mental processes involved in planning, organizing, time management and regulating emotions, among other things. People with ADHD often have abnormal executive function.
The results showed that the patients with ADHD had altered structure and function located in areas of the brain like the orbitofrontal cortex, which is primarily involved in the cognitive processing of strategic planning, and the globus pallidus, which is involved in executive inhibitory control.
"Our study suggests that the structural and functional abnormalities in these brain regions might cause the inattention and hyperactivity of the patients with ADHD, and we are doing further analysis on their correlation with the clinical symptoms," said Qiyong Gong, M.D., Ph.D., a neuroradiologist from the Department of Radiology at West China Hospital of Sichuan University in Sichuan, China. "Our preliminary results show the association between imaging findings and symptoms."
The researchers also found abnormalities in the connections between resting-state brain networks associated with executive dysfunction. These abnormalities indicate more widespread brain alterations in ADHD than previously had been shown, Dr. Gong said.
Exploration of the association between brain activity and executive function might be useful in better characterizing patients with ADHD and in understanding the pathophysiology underlying the condition, according to Dr. Gong.
"Our results suggest the potential clinical utility of the rfMRI changes as a useful marker, which may help in diagnosis and in monitoring disease progression and, consequently, may inform timely clinical intervention in the future," he said.
Dr. Gong indicated that larger studies are needed to validate the results. The researchers also plan to study changes in connectivity over time in ADHD patients and explore the potential differences of functional connectivity between the clinical subtypes of ADHD, such as inattentiveness and hyperactivity.
The ADHD study is part of a larger project from Dr. Gong's group at Huaxi MR Research Center of the West China Hospital to explore MRI's diagnostic and prognostic potential in psychiatric disorders.
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"Intrinsic Brain Abnormalities in Attention Deficit Hyperactivity Disorder: A Resting-State Functional MR Imaging Study." Collaborating with Dr. Gong were Fei Li, Ph.D., Ning He, M.D., Yuanyuan Li, M.D., Lizhou Chen, M.D., Xiaoqi Huang, Ph.D., Su Lui, Ph.D., Lanting Guo, M.D., and Graham J. Kemp, M.A., D.M.
RSNA is an association of more than 53,000 radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill.
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If you have ever said or done the wrong thing at the wrong time, you should read this. Neuroscientists at The University of Texas Health Science Center at Houston (UTHealth) and the University of California, San Diego, have successfully demonstrated a technique to enhance a form of self-control through a novel form of brain stimulation.
Study participants were asked to perform a simple behavioral task that required the braking/slowing of action – inhibition – in the brain. In each participant, the researchers first identified the specific location for this brake in the prefrontal region of the brain. Next, they increased activity in this brain region using stimulation with brief and imperceptible electrical charges. This led to increased braking – a form of enhanced self-control.
This proof-of-principle study appears in the Dec. 11 issue of The Journal of Neuroscience and its methods may one day be useful for treating attention deficit hyperactivity disorder (ADHD), Tourette's syndrome and other severe disorders of self-control.
"There is a circuit in the brain for inhibiting or braking responses," said Nitin Tandon, M.D., the study's senior author and associate professor in The Vivian L. Smith Department of Neurosurgery at the UTHealth Medical School. "We believe we are the first to show that we can enhance this braking system with brain stimulation."
A computer stimulated the prefrontal cortex exactly when braking was needed. This was done using electrodes implanted directly on the brain surface.
When the test was repeated with stimulation of a brain region outside the prefrontal cortex, there was no effect on behavior, showing the effect to be specific to the prefrontal braking system.
This was a double-blind study, meaning that participants and scientists did not know when or where the charges were being administered.
The method of electrical stimulation was novel in that it apparently enhanced prefrontal function, whereas other human brain stimulation studies mostly disrupt normal brain activity. This is the first published human study to enhance prefrontal lobe function using direct electrical stimulation, the researchers report.
The study involved four volunteers with epilepsy who agreed to participate while being monitored for seizures at the Mischer Neuroscience Institute at Memorial Hermann-Texas Medical Center (TMC). Stimulation enhanced braking in all four participants.
Tandon has been working on self-control research with researchers at the University of California, San Diego, for five years. "Our daily life is full of occasions when one must inhibit responses. For example, one must stop speaking when it's inappropriate to the social context and stop oneself from reaching for extra candy," said Tandon, who is a neurosurgeon with the Mischer Neuroscience Institute at Memorial Hermann-TMC.
The researchers are quick to point out that while their results are promising, they do not yet point to the ability to improve self-control in general. In particular, this study does not show that direct electrical stimulation is a realistic option for treating human self-control disorders such as obsessive-compulsive disorder, Tourette's syndrome and borderline personality disorder. Notably, direct electrical stimulation requires an invasive surgical procedure, which is now used only for the localization and treatment of severe epilepsy.
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The study's co-lead authors are Jan R. Wessel, Ph.D., of the Department of Psychology at the University of California, San Diego; and Christopher R. Conner, student at the UTHealth Medical School. The fourth author is Adam Aron, Ph.D., at the University of California, San Diego.
The study is titled "Chronometric Electrical Stimulation of Right Inferior Frontal Cortex Increases Motor Braking." Authors received support from the National Institutes of Health Center for Clinical and Translational Sciences (KL2RR0224149), the Mischer Neuroscience Institute at Memorial Hermann-TMC and the Keck Center of the Gulf Coast Consortia.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
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