Children with attention disorders struggle to process whole faces during social interactions

Children with attention-deficit/hyperactivity disorder often struggle to automatically track where other people are looking. A recent study published in the Journal of Attention Disorders revealed that this difficulty stems from challenges in processing whole faces, rather than an inability to notice simple eye movements. These results help explain the social difficulties sometimes experienced by children with the disorder and point toward potential support strategies in classrooms.

Attention-deficit/hyperactivity disorder is primarily known for symptoms like impulsivity, hyperactivity, and a general lack of focus. However, individuals with the condition also frequently experience atypical social interactions and struggle to read nonverbal cues.

During everyday conversations, people naturally follow the gaze of others. This behavior helps individuals seamlessly understand what is catching a friend or teacher’s interest.

Psychologists divide the human attention system into two separate categories. The first is endogenous attention, which is a deliberate, goal-oriented process driven by a person’s own expectations and prior knowledge.

The second type is exogenous attention. This is an automatic, reflex-like reaction to something standing out in the environment, like a sudden flash of light or a loud noise.

When a person sees someone else move their eyes, both types of attention are triggered simultaneously. A social and intentional thought process occurs, but there is also a reflexive reaction to the physical movement of the eyes.

Because children with attention-deficit/hyperactivity disorder often miss social cues, researchers have questioned how they process eye movements. Past research suggested they might not orient their attention in the same way that typically developing children do.

Jiaqi Wang, a researcher at Guangxi Normal University in China, worked with a team of colleagues to investigate this exact phenomenon. The researchers wanted to isolate the reflexive, automatic part of attention to see if it functions differently in children with the disorder.

To measure this automatic response, the research team looked for a specific psychological reaction called inhibition of return. This reaction happens when a person’s attention is drawn to a specific spot, but nothing else happens there for a brief period.

When a target finally does appear in that spot, the person’s brain actually reacts slower than it would if the target appeared somewhere entirely new. The brain essentially marks the first spot as old news and resists looking back at it.

This slowed reaction is believed to be an evolutionary mechanism that encourages humans to search new areas rather than checking the same spot repeatedly. Because this delayed reaction only happens with automatic, reflex-like attention, it serves as a perfect measuring stick for researchers.

If a child shows this slowed reaction after looking at a gaze cue, it means their brain automatically processed the eye movement. If they do not, it indicates a breakdown in their automatic attention system.

To test these reactions, Wang and the research team designed a precise computer-based experiment. They recruited a group of children diagnosed with attention-deficit/hyperactivity disorder and a matched group of typically developing children.

The children sat in front of a screen and looked at a photograph of a normal, neutral human face. The eyes on the face would suddenly look to the left or the right.

After a specific time delay, a small star symbol appeared on the screen. This target either appeared on the side the face was looking toward, or on the completely opposite side.

The children were instructed to press a keyboard button as quickly as possible to indicate where the star appeared. The researchers tracked their response times down to the millisecond to catch tiny differences in cognitive processing.

With a very short time delay, both groups of children found the star faster when the face looked in the correct direction. This meant all the children successfully shifted their initial attention based on the gaze cue.

The results entirely diverged when the researchers extended the time delay to more than two seconds before the star appeared. The typically developing children eventually showed the expected slowed reaction, meaning their automatic attention systems had engaged perfectly.

The children with the disorder did not show this slowed reaction at all. This lack of an inhibition response indicated that their ability to automatically orient their attention to the human gaze was impaired.

Wang and the team then needed to figure out exactly why this impairment happened. Two entirely different visual details trigger automatic attention when a face looks away.

One detail is the simple physical change of the dark pupil moving against the white background of the eye. The other detail is the brain’s recognition of the complete, intact human face as a social entity.

To separate these two visual details, the researchers conducted a second experiment using the exact same computer task. This time, they turned all the photographs of the faces upside down.

Flipping a face upside down scrambles the brain’s ability to process it as a complete human face. However, the physical contrast of the dark pupil moving across the white eye remains completely visible and intact.

In this second experiment, the children with attention-deficit/hyperactivity disorder finally displayed the automatic slowed reaction. Because the upside-down face removed the complex social context, the children were able to react reflexively to the simple physical movement of the eyes.

This outcome isolated the exact source of the children’s visual tracking difficulties. They possess no trouble seeing or reacting to basic eye movements, but their brains struggle to automatically process those movements when they are embedded in a normal, right-side-up face.

The team concluded that a deficit in processing whole, intact faces disrupts the automatic social reflexes of these children. This specific impairment helps explain why they might miss subtle nonverbal cues during fast-paced social interactions.

While the study offers deep insights into social attention, the authors acknowledged a few limitations in their work. The sample size of children was relatively small, which meant some of the broader statistical comparisons were not statistically significant.

Future research will need to include a much larger group of participants to confirm these patterns more robustly. The researchers aim to recruit over one hundred children per group in upcoming projects to ensure maximum statistical power.

Attention disorders also frequently share overlapping traits with autism spectrum conditions. Some of the children in the study might have possessed undiagnosed characteristics related to autism.

These overlapping traits could independently affect how a child processes social cues and eye movements. Future studies will need to screen for these specific traits to isolate the exact cause of the attention differences.

The researchers also relied heavily on parent interviews to confirm the behavioral diagnoses of the children. Moving forward, they plan to incorporate direct evaluations from school teachers to ensure the behavioral symptoms are consistent across different environments.

The study, “Impaired Exogenous Attentional Orienting to Gaze Cues in Children With ADHD: Evidence From Inhibition of Return,” was authored by Jiaqi Wang, Aijun Wang, Jiacan Gu, Shizhong Cai, and Ming Zhang.