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ADHD Caused By Disconnected Brain Regions

Interesting new research from the University of California-Davis Center for Mind and Brain shows a possible cause for ADHD.  You may have already known that the brains of children with ADHD tend to exhibit abnormal brain wave patterns.  In situations where they should be concentrating and processing information, they're more likely to show strong alpha waves, the brain waves that indicate a state of daydreaming.  Researchers believe that this may be caused when two brain regions fail to connect with each other.

This was discovered when the researchers measured the brain wave patterns of children with ADHD and children without. While this was happening, the children took a simple test of attention.  They were shown a red or blue picture, made to listen to a high-pitched or low-pitched sound, and asked to respond by pressing a button.  Before the items were shown, the children were shown the letter A to alert them to prepare for an audio item or V to alert them to prepare for a picture.

Although children with ADHD did not have delayed reaction times when they received the right cues, there was a slight difference in the way their brains prepared to receive information.  According to what we know about how the brain pays attention, the signals from the frontal context (triggered by the A and V cues) should alert the other regions of the brain to pay attention to the stimuli.  This should have been shown by reduced alpha wave activity in the audio processing region when the A sound was given.  These brain wave patterns were found in children without ADHD, but those with the disorder showed no change in alpha wave activity. This observation indicates a disconnect between the frontal cortex (the region of the brain that allocates attention) and the sensory processing regions.

The findings of this study provide the first evidence for a functional disconnect in the attention systems of the brain in children with ADHD.  The researchers did not indicate what they intend to do with these findings, but it looks as though their experiments might make a good foundation for specialized ADHD testing.