[ADHD = attention deficit/hyperactivity disorder. Photo Credit: Pixabay]

A scientific study published on December 16th by researchers at Guangxi Normal University in the Journal of Attention Disorders revealed that it can be difficult for children with attention-deficit/hyperactivity disorder (ADHD) to instinctively notice where other people are looking.

Children who are affected consequently face challenges in automatically detecting where others are looking.

The main symptoms of ADHD are impulsivity, hyperactivity, and a general lack of focus; but people with the illness also often have unusual social relationships and trouble interpreting nonverbal clues.

People instinctively follow each other's gazes during casual conversations, which makes it easier for people to understand what a friend or teacher is interested in.

Psychologists classify the human attention system into two distinct categories;  endogenous attention (a goal-oriented process motivated by an individual's expectations and past knowledge) and external attention (a reflexive, automatic response to something that stands out in the surroundings). 

Both forms of attention are activated simultaneously when someone observes another person moving their eyes. There is a reflexive response to the actual movement of the eyes in addition to a social and intentional mental process.

Researchers have questioned how children with attention-deficit/hyperactivity disorder interpret eye movements since they frequently fail to notice social cues. 

In an effort to better understand this phenomenon, researchers at Guangxi Normal University separated out the reflexive, automatic component of attention to determine if it operated differently in children with the disease.

The research team searched for a certain psychological reaction known as inhibition of return in order to quantify this instinctive response. 

This reaction occurs when someone's attention is focused on a certain area and nothing else occurs there for a short while.

The brain essentially marks the original spot as old news and refuses to look back at it. So, when a target eventually appears there, it reacts more slowly than it would if the target came somewhere completely fresh.

It is thought that this slower response is an evolutionary strategy that encourages people to explore new places rather than continuously checking the same location. 

A child's brain automatically processes eye movement, and a  slower reaction to a gaze signal could indicate a malfunction in their automatic attention mechanism.

The researchers conducted a controlled computer-based experiment involving ADHD children and a group of typically developing peers, in which participants viewed a neutral human face on a screen whose gaze would suddenly shift left or right, followed after a set delay by the appearance of a small star either in the same direction as the gaze or on the opposite side.

The participants were instructed to press a keyboard key as quickly as possible to indicate the star’s location while their response times were measured with millisecond precision.

The findings showed that with short delays, both groups located the star more quickly when it appeared in the gaze-congruent direction, indicating successful initial attention shifts, but when the delay exceeded two seconds, only the typically developing children demonstrated the expected slowing of responses. 

The children with ADHD showed no such slowing, revealing a deficit in their ability to inhibit and automatically orient attention based on social gaze cues.

Although the study provides profound insights into social attention, the authors acknowledged certain limitations in their research, particularly that some of the more general statistical comparisons were not statistically significant because of the small sample size of youngsters.