After teachers explain an assignment, children with attention deficit/hyperactivity disorder might struggle to turn those instructions into action. It’s one of several pathways by which ADHD can impair a young student’s academic performance.

“When you hear something from a teacher, you need to maintain the information in your brain, then process it and make decisions based on what you heard,” said Stanford Medicine cognitive neuroscientist Hadi Hosseini, PhD.

These steps require students to engage their working memory, a brain system that holds information for short periods of time. When the system doesn’t work, it can cause frustration both for the kids themselves and for teachers, parents and others who are trying to help them learn normal tasks and activities, such as finishing an assignment or remembering to bring their coat in from the playground.

Hosseini’s team has been studying a technique to help kids with ADHD strengthen their working memory. The latest research was led by Hosseini, Ali Rahimpour Jounghani, PhD, a postdoctoral scholar in psychiatry, and Elveda Gozdas, PhD, an instructor in psychiatry and behavioral sciences.

The team’s work shows that a portable, low-cost brain imaging tool can provide children with real-time feedback about what their brains are doing during cognitive tasks. Kids wore a special cap on their head that sends and receives infrared light, letting researchers track blood oxygen levels in specific parts of their brain as a proxy for brain activity. The treatment group of 21 children who completed the 12-week program were compared to 15 kids in a control group, who got their usual ADHD treatment.

Most kids with ADHD who completed the program improved their ability to perform tasks that required working memory. About half of them also had improvements in ADHD symptoms, as measured by a standard questionnaire. The concept holds promise for other neuropsychiatric conditions, too, said Hosseini, an associate professor of psychiatry and behavioral sciences at Stanford Medicine, who spoke with us for a Q&A about his research.

Why did your team decide to study working memory in children with ADHD?

We’re trying to address deficits in executive function, the process by which we handle everyday tasks including planning, decision making and learning. Executive function deficits show up in many mental health conditions, including autism, depression, and obsessive-compulsive disorder.

Working memory is a big component of executive functioning: It temporarily holds a limited amount of information in your brain so you can attend to it in the right way. The neural systems involved in working memory are impacted in the majority of kids with ADHD. In addition, modern neuroscience looks at ADHD as more of a problem of attention regulation than an attention deficit, per se, and working memory is important for regulating one’s attention.

This means ADHD was a logical starting place to test our intervention. It’s also a good condition to study because it is quite common, and because scientists have a strong understanding of the neural architecture that is affected.

Neuroimaging research has shown hypoactivation – or under-activity – in the prefrontal cortex of people with ADHD. We were trying to help children increase their brain activity in that region, which is located at the very front of the brain and is involved in many kinds of complex thinking and decision making.

What was your research process?

Our study used neurofeedback, which means giving people real-time information from brain imaging so they can consciously strategize and try to control their brain function. A parallel idea is biofeedback – for instance, where we measure how fast your heart is beating and show you strategies to calm it down.

At the beginning of our study, we scanned each child’s brain so we could identify where in their prefrontal cortex they had low activation. There is a lot of variation between individuals with ADHD, so we identified a personalized target region for each patient.

For each session of the intervention, each child was fitted with a special cap on their head that sends and receives infrared light. This let the research team monitor what was happening in the child’s brain via a technique called functional near-infrared spectroscopy, in which the light travels partway into the brain and we measure how it is reflected back. This gives a view into changes in blood oxygen levels in specific brain areas, indicating changes in brain activity. The disadvantage of using this imaging method is that you can’t look into subcortical regions deep in the brain. But the prefrontal cortex, where working memory happens, is actually pretty accessible to infrared light.

The kids in our study came to the lab for 12 sessions, each for around 20-30 minutes of active intervention. Once connected to the imaging cap, they performed a memory task during which they saw a string of letters on a computer screen and memorized it for a few seconds, then saw a target letter and had to indicate if it was in the original string.

During the task, we provided feedback – onscreen images of gold coins – if they were doing the task correctly and successfully engaging the target region of their brains. We don’t tell them how to do it, and we think individuals might get there in different ways, but with this method, they can immediately see when they’re on target.  

Why is it important that this intervention be personalized?

We need treatments that deal with the varied ways that psychiatric disorders manifest in the brain. We diagnose ADHD based on combinations of behavioral symptoms, but when you look at the underlying biology, there is a huge spectrum. So we can’t come up with a single solution that fits everyone.

Other treatments have personalized elements; for example, a patient might work with their doctor to try different ADHD medications and identify which best manages symptoms. But our method has the additional element of measuring the patient’s brain activity and enabling them to use that information right away.

Some brain scanning methods, such as functional MRI, can be conducted only with the patient lying in a scanner the size of a small room. How does the functional near-infrared spectroscopy technology compare?

This technology is much cheaper and more portable, which gives more patients access to it.

We have a prototype for a functional near-infrared spectroscopy headband and tablet we’re developing that kids can use at home to benefit from imaging data without the presence of a psychiatrist or researcher. We’re iterating different versions of that technology, starting with adults, and haven’t started collecting data from patients using it at home, but I think it will be there soon.

 Why is this exciting to you, as an ADHD expert?

One reason is there aren’t any approved medications for improving working memory. The medications prescribed for ADHD mostly target attention in other ways. With kids specifically, the real promise here lies in the opportunity to intervene early to change the trajectory of their neurodevelopment.

Prior neurofeedback studies for ADHD have given patients feedback about what’s happening in their brains. There have also been training studies aimed at strengthening particular cognitive skills. I think what is helpful here is that we are integrating those components.

I hope our method can be applied to many conditions that impede executive function deficits.