These images of brain scans were taken while the subjects performed mathematical calculations involving serial addition. The results show significant differences between the thought processes of the subjects with attention deficit hyperactivity disorder and those without adhd. The yellow spots show regions of the brain where blood flow increased during performance of the task.
Each image, taken using a positron emission tomography, or PET, scan, is based on averaged images from a group of six subjects with ADHD and six control subjects. In these brain scans, activity in the right hemisphere is displayed on the left side of the image, and left-hemisphere activity is displayed on the right side.
The subjects without ADHD showed more activity in the frontal part of the brain that is associated with attention. Also, those subjects used the middle regions of their brains associated with processing verbal strategies. The researcher, Julie Schweitzer, says that is because the subjects without ADHD seemed to hear the auditory prompt and talk themselves through the problem using words.
In contrast, the subjects with ADHD used different parts of their brains, associated with visualization. Schweitzer says some of the subjects diagnosed with the disorder told her after the test that they had pictured images in their heads—for example, a chalkboard with numbers written on it—to help in doing the calculations.
The data were collected between 1997 and 1999. The study appeared in the February 2000 issue of the American Journal of Psychiatry.
SOURCE: The Maryland Psychiatric Research Center’s Web page on Julie Schweitzer’s work, at http://www.umaryland.edu/mprc/faculty/schweitzer.html
