Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain abnormality found in boys with attention deficit hyperactivity disorder

19.03.2009
Researchers trying to uncover the mechanisms that cause attention deficit hyperactivity disorder and conduct disorder have found an abnormality in the brains of adolescent boys suffering from the conditions, but not where they expected to find it.

Boys with either or both of these disorders exhibited a different pattern of brain activity than normally developing boys when they played a simple game that sometimes gave them a monetary reward for correct answers, according to a new study by a University of Washington research team.

The research focused on two brain areas, the striatum and anterior cingulate cortex. The striatal region is a network of structures in the mid brain that motivates people to engage in pleasurable or rewarding behavior. The anterior cingulate is higher in the brain and normally activates when an expected reward stops. However, this process, called extinction, doesn't occur, at least as quickly, in boys with attention deficit hyperactivity or conduct disorders. Instead, the striatal region continues to be activated, said Theodore Beauchaine, a UW associate professor of psychology and senior author of the paper.

"When children engage in impulsive behavior they are looking to stimulate themselves and have fun. Children with attention deficit hyperactivity disorder are always looking to have fun and that is what gets them in trouble," he said. "A behavior should stop when the reward stops. When you stop the reward for children with these disorders, they continue to focus on the reward long afterward and the anterior cingulate does not appear to become activated."

Attention deficit hyperactivity disorder is one of the most common mental disorders among children, affecting between 3 and 5 percent of school-age youngsters, or an estimated 2 million.

The researchers used functional magnetic resonance imaging to compare brain activity in 19 boys with either or both disorders and 11 normally developing boys. The adolescents ranged in age from 12 to 16.

Their brains were scanned while they played the game. The boys looked at a screen and there was a button under each of their thumbs. When a light flashed on the left or right side of the screen they were instructed to press the button on that side. The screen lit up very fast, up to 100 times a minute. The boys received five cents for each correct response and could win up to $50. They were not penalized for wrong answers and their accumulated winnings showed up on the screen.

Each boy had four five-minute blocks of trials. The first and third trials involved opportunities to earn money. The second and fourth trials did not involve winning money, but the boys were told to keep playing the game because the game would change at some point.

Beauchaine said there was no difference in the accuracy or speed – the behavioral response – between the two groups. But there was a difference in brain activation. When the non-reward blocks came up the anterior cingulate lit up for normally developing boys, but those with either of the disorders, which frequently co-occur, continued to only show activation in the striatum.

"This shows there is an abnormality, but not in the place we expected to find it. We expected to find a difference in the way the striatum functions, but instead found it in anterior cingulate functioning," said Beauchaine.

Joel Schwarz | EurekAlert!
Further information:
http://www.washington.edu

More articles from Health and Medicine:

nachricht Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>