News on Wellness

ADHD: Angry Expressions Not Recognized by the Brain

adhdAccording to researchers with the National Institutes of Natural Sciences, characteristics of facial expression recognition in children with Attention Deficit Hyperactivity Disorder (ADHD) have been identified by measuring hemodynamic response within the brain, findings published in Neuropsychologia.

From a new study, researchers were able to show that children with ADHA had significant hemodynamic response when making a happy expression but not for an angry expression. The experts believe this difference in the neural basis for recognition of facial expression could be responsible for social recognition impairment, as well as the establishment of peer relationships.

Children with ADHD who present with inattention, impulsive, and hyperactivity behavior often struggle in social settings. Because of this, these children are often left out from normal play and interactive activities. From this study, researchers discovered that these same children have impaired recognition of emotional expression in other people.

The study was led by Professor Ryusuke Kakigi with the National Institute of Physiological Sciences and the National Institutes of Natural Sciences but also in collaboration with Assistant Professor Hiroko Ichikawa and Professor Masami K. Yamaguchi with the Chuo University.

Together, these experts first identified facial expression recognition characteristics in children with ADHD by measuring the brain’s hemodynamic response. From this the possibility of neural basis for facial expression recognition was different from what they saw in children without ADHD.

Images of a happy or angry expression were shown to 13 children diagnosed with ADHD and 13 children without this disorder. They also identified the specific area of the brain that was activated during this process by using non-invasive near-infrared spectroscopy as a means of measuring brain activity. The near-infrared light that usually goes through the body was projected through the subject’s brains and scattered or absorbed light was then measured.

Concentration in oxyhemoglobin, which provides oxygen to nerve cells actively working, was used to determine the strength of the light. From this, researchers found that normal developing children had significant hemodynamic response to both happy and angry expressions within the brain’s right hemisphere.

In comparison, significant hemodynamic response in the children with ADHD was seen only with the happy expression. However, researchers were unable to observe brain activity specific to the angry expression. This difference in the neural basis for facial expression recognition could be the reason for impairment in social recognition, as well as establishment in peer relationships.

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