Navigation Links
Faulty 'off-switch' stops children with ADHD from concentrating
Date:1/6/2011

Brain scans of children with attention-deficit/hyperactivity disorder (ADHD) have shown for the first time why people affected by the condition sometimes have difficulty in concentrating. The study, by experts at The University of Nottingham, may explain why parents often say that their child can maintain concentration when they are doing something that interests them, but struggles with boring tasks.

Using a 'Whac-a-Mole' style game, researchers from the Motivation, Inhibition and Development in ADHD Study (MIDAS) group found evidence that children with ADHD require either much greater incentives or their usual stimulant medication to focus on a task.

The research, funded by the Wellcome Trust, found that when the incentive was low, the children with ADHD failed to "switch off" brain regions involved in mind-wandering. When the incentive was high, however, or they were taking their medication, their brain activity was indistinguishable from a typically-developing non-ADHD child.

Professor Chris Hollis, in the School of Community Health Sciences, led the study. He said: "The results are exciting because for the first time we are beginning to understand how in children with ADHD incentives and stimulant medication work in a similar way to alter patterns of brain activity and enable them to concentrate and focus better. It also explains why in children with ADHD their performance is often so variable and inconsistent, depending as it does on their interest in a particular task."

ADHD is the most common mental health disorder in childhood, affecting around one in 50 children in the UK. Children with ADHD are excessively restless, impulsive and distractible, and experience difficulties at home and in school. Although no cure exists for the condition, symptoms can be reduced by medication and/or behavioural therapy. The drug methylphenidate (more often known by the brand name Ritalin) is commonly used to treat the condition.

Previous studies have shown that children with ADHD have difficulty in 'switching-off' the default mode network (DMN) in their brains. This network is usually active when we are doing nothing, giving rise to spontaneous thoughts or 'daydreams', but is suppressed when we are focused on the task before us. In children with ADHD, however, it is thought that the DMN may be insufficiently suppressed on 'boring' tasks that require focused attention.

The MIDAS group researchers, which included Dr Martin Batty and Dr Elizabeth Liddle, compared brain scans of 18 children with ADHD, aged between nine and 15 years old, against scans of a similar group of children without the condition as both groups took part in a task designed to test how well they were able to control their behaviour. The children with ADHD were tested when they were taking their methylphenidate and when they were off their medication. The findings are published in the Journal of Child Psychology and Psychiatry.

Whilst lying in a magnetic resonance imaging (MRI) scanner, which can be used to measure activity in the brain, the children played a computer game in which green aliens were randomly interspersed with less frequent black aliens, each appearing for a short interval. Their task was to 'catch' as many green aliens as possible, while avoiding catching black aliens. For each slow or missed response, they would lose one point; they would gain one point for each timely response.

To study the effect of incentives, the reward for avoiding catching the black alien was then increased to five points, with a five-point penalty incurred for catching the wrong alien.

By studying the brain scans, the researchers were able to show that typically developing children switched off their DMN network whenever they saw an item requiring their attention. However, unless the incentive was high, or they had taken their medication, the children with ADHD would fail to switch off the DMN and would perform poorly. This effect of incentives was not seen in children without ADHD activity in their DMN was switched off by items requiring their attention regardless of the incentive on offer.

Dr Batty said: "Using brain imaging we have been able to see inside the children's heads and observe what it is about ADHD that is stopping them concentrating. Most people are able to control their 'daydreaming' state and focus on the task at hand. This is not the case with children with ADHD. If a task is not sufficiently interesting, they cannot switch off their background brain activity and they are easily distracted. Making a task more interesting or providing methylphenidate turns down the volume and allows them to concentrate."

Dr Liddle said: "These findings help explain one of the interesting characteristics of ADHD that children with the condition appear able to control themselves much better when motivated to do so.

"The common complaint about children with ADHD is that 'he can concentrate and control himself fine when he wants to', so some people just think the child is being naughty when he misbehaves. We have shown that this may be a very real difficulty for them. The off-switch for their 'internal world' seems to need a greater incentive to function properly and allow them to attend to their task."


'/>"/>

Contact: Lindsay Brooke
lindsay.brooke@nottingham.ac.uk
44-115-951-5751
University of Nottingham
Source:Eurekalert  

Related medicine news :

1. Faulty gene stops cell antennae from transmitting
2. Web Site for Hospital Comparisons Is Faulty: Study
3. Drug Targets Faulty Process That Drives Cystic Fibrosis
4. Vaccine Stops Tumor Spread in Mice
5. Cartoon Network's MOVE IT MOVEMENT TOUR Stops in Seattle Market
6. Traditional Marketing is Dead! GLM Creates a Sales Spike in Under 60 Days Stops Business Failure; Provides Startup Funding
7. Drug That Stops Bleeding Could Save Lives
8. Art Mann stops by The Elator booth at the AVN Expo in Las Vegas
9. Success stops drug trial
10. Hemostatic powder stops bleeding ulcers: Doctor
11. Drug-like compound stops thyroid overstimulation in early NIH studies
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Faulty 'off-switch' stops children with ADHD from concentrating
(Date:6/26/2016)... ... ... PawPaws brand pet supplements owned by Whole Health Supply is ... of felines. The formula is all-natural and is made from Chinese herbs that have ... Kidney Support Supplement Soft Chews are Astragalus Root Extract and Rehmannia Root Extract ...
(Date:6/26/2016)... (PRWEB) , ... June 26, 2016 , ... ... fertility once they have been diagnosed with endometriosis. These women need a treatment ... also require a comprehensive approach that can help for preservation of fertility and ...
(Date:6/25/2016)... TX (PRWEB) , ... June 25, 2016 , ... Austin ... of the American College of Mohs Surgery and to Dr. Russell Peckham for medical ... and highly effective treatment for skin cancer. The selective fellowship in Mohs Micrographic Surgery ...
(Date:6/25/2016)... , ... June 25, 2016 , ... "With 30 hand-drawn ... specific project," said Christina Austin - CEO of Pixel Film Studios. , ProHand ... all within Final Cut Pro X . Simply select a ProHand generator and ...
(Date:6/25/2016)... CA (PRWEB) , ... June 25, 2016 , ... As ... with Magna Cum Laude and his M.D from the David Geffen School of Medicine ... and returned to Los Angeles to complete his fellowship in hematology/oncology at the UCLA-Olive ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... Research and Markets has announced the addition of the ... report to their offering. ... failure, it replaces the function of kidneys by removing the ... the treatment helps to keep the patient body,s electrolytes such ... Increasing number of ESRD patients & substantial healthcare expenditure on ...
(Date:6/23/2016)... Research and Markets has announced the addition of the ... to 2022" report to their offering. ... financial data derived from varied research sources to present unique ... on the market during the next five years, including a ... markets, regional and country level analysis. The report provides a ...
(Date:6/23/2016)... and INDIANAPOLIS , June ... receiving a Lilly Diabetes Tomorrow,s Leaders Scholarship is any ... scholarship winners, announced today online at www.diabetesscholars.org ... type 1 diabetes stand in the way of academic ... supported the Foundation,s scholarship program since 2012, and continues ...
Breaking Medicine Technology: