Researchers discover a brain signal that predicts a child’s attention deficit

Inside a world-leading intensive brain stimulation program at The Hospital for Sick Children (SickKids), researchers have discovered a brain signal that predicts when a child is about to lose attention – and a brief, targeted intervention in response to that signal can restore their attention.

Their study, published in nature neuroscienceMarks the first time this approach to attention control has been studied in people.

Few aspects of the human experience are as integral as meditation. It shapes our perceptions, memories, and interactions, but what happens when it is compromised?”

Dr. George Ibrahim, lead author, neurosurgeon and senior scientist in the Neuroscience and Mental Health Program

While fluctuations in attention are natural, disruptions in “attentional flexibility” that occur in youth with attention-deficit/hyperactivity disorder (ADHD) may have negative behavioral, psychosocial, and academic consequences. The drugs used today are limited in their effects because, until now, we did not know exactly how attention wanders occur nor which neural networks in the brain are involved.

Unique study provides new insight into the brain

The study first began with an attention set-shifting task – which measures how attention changes between stimuli – in a group of 30 children with epilepsy, a condition that significantly increases the risk for ADHD.

The team performed intracranial recordings, in which electrodes record directly from deep in the brain, allowing them to monitor neural activity in milliseconds. Additionally, they used machine learning models to predict fluctuations in attention – a first in the world. Through models, they pinpointed a specific pattern of brain activity that predicted slow or fast attention shifts in all children over several days.

“We were surprised to detect a signature in the brain that arose just before each child demonstrated a delay in shifting attention,” says Dr. Nebras Warsi, first author of the study and a pediatric neurosurgeon-scientist in the Ibrahim lab. “With precise electrical stimulation at these moments, each child remained engaged despite difficult tasks and performed them faster and more accurately.”

During various 20 to 30-minute tasks, they monitored the children’s performance through eye tracking, reaction time, and accuracy to catch lapses in attention. Brief electrical stimulation saved their attention only when given at the right time; When delivered at other times, participant performance declined.

In short: timing was everything.

Expanding the scope to other children

Can similar results be expected in other children without epilepsy? To find out, researchers used non-invasive magnetoencephalography imaging in 37 typically developing children and 25 children with ADHD.

By targeting the same signal in their brain, researchers could once again predict attention delays. Next, they used noninvasive transcranial magnetic stimulation-electroencephalography (TMS-EEG) and found that a single pulse delivered to that target area significantly improved reaction time and accuracy. This time with a simple EEG cap and TMS coil, there is no need for intracranial brain electrodes.

This suggests long-term potential for non-invasive devices that can help provide attention when it is most needed.

Although these technologies are still in their early days, Ibrahim says it opens a promising new direction for understanding attentional challenges and being able to advance precision child health at SickKids and around the world, by supporting each child in an individualized way.

“A lot of people are studying neurological and neuropsychiatric disorders in adults, but very few are expanding into pediatrics,” says Ibrahim, who is also the Abe Brasover Chair in Functional Neurosurgery. “We need to ethically pursue potential treatments for children and young people and to do this, we need to understand the neural circuitry.

“The ability to change the lives of so many children is extremely significant.”

The study is supported by the Canadian Institutes of Health Research (CIHR), Brain Canada through the Ezraeli Future Leader in Canadian Brain Research Award, and the Abe Brasover Chair in Functional Neurosurgery at SickKids. Dr. Warsi is supported by the CIHR Vanier Scholarship, the James and Marie Rutka Surgeon-Scientist Award, and the Edward Christie Stevens Fellowship in Medicine.