Imagine planting a seed. As you pat the soil, the seed blows up into a tree at an uncontrollable rate.
The ADHD mind can sometimes be the exploding tree: A background noise or thought can branch off into a massive number of other thoughts (More on this later).
Around the world, there are 129 million such trees and others that feel similarly distracted. And when young trees grow up, who can imagine how society’s work efficiency will be changed?
We will briefly look at how the ADHD mind differs, bugs with the current diagnosis process, treatment, along with how Brain-Computer Interfaces can help.
Background
Abbreviation
ADHD stands for Attention-deficit/hyperactivity disorder. People with ADHD show inattention and/or hyperactivity and impulsivity that disrupts their life. It is tricky to define as well as diagnose since there is much behavioural variance across the population.
The exploding tree cycle
As mentioned, a thought could branch into numerous others. To deal with the number of thoughts, they climb the ladder of abstraction to extrapolate general rules about the universe. Then the task becomes exhausting, so novelty seeking can be a nice relief. The next time they return to the problem, there isn’t any novelty so it becomes big and boring.
Thus, the task itself does not get done, and there is no reward from completing a task which exacerbates the cycle.
All this time, working memory is being flooded and after a point, blocks new learning, which can show up as inattentiveness.
What is a Brain-Computer Interface?
A Brain-Computer Interface (BCI) can read and write to the brain. This means it can read from the brain for ADHD diagnosis or understanding, and then stimulate the brain for treatment.
Diagnosis
Currently, to be diagnosed with ADHD, a survey regarding the behaviour of the last 6 months needs to be done with multiple people.
Misdiagnoses are common: Some have moodiness, obsessive-compulsive tendencies and some don’t have trouble with attention.
However, there are detectable similarities in brain signals among some patients.
The Neuropsychiatric EEG-Based Assessment Aid (NEBA) system was approved for ADHD diagnosis in 2013. It is used side by side with results from clinical examinations for diagnosis decisions.
How does it work?
To begin, the brain communicates by neurons charging and discharging, which is caused by the flow of ions in and out of the neuron membrane.
Like charges repel. When many neurons are pushing out large numbers of ions, the neighbouring ions will be pushed away, and so on, forming a wave, which eventually push or pull the electrodes on the scalp. This becomes a voltage.
To be able to extract the location of the neural signal, the voltage difference between two electrodes is compared and graphed.
This procedure of measuring activity with electrodes placed along the scalp is called Electroencephalography (EEG).
The NEBA system compares activity between two electrodes: Cz and Fz. Additional electrodes are placed near the ears, a quiet spot from electrical activity, for reference.
On the EEG recording, there are repeat waveforms that contain information. For example, a shape that repeats at a frequency of 30 times per second, or a gamma brainwave, is indicative of problem-solving tasks.
Here are the 5 major types of brainwaves (credits to muse headband)
The NEBA system detects the ratio of Theta to Beta brainwaves during a 15-minute test. Ratios above 2 usually indicate difficulty paying attention, falling asleep, etc and are associated with inattention in ADHD.
When the NEBA system was tested on 209 children meeting ADHD criteria according to clinicians, multidisciplinary experts noticed 93 children less likely to fit the criterion, while the system marked 85 of these subjects (due to low theta-beta ratio). Specific calculations signify the combined approach improved the accuracy from 61% to 88%. These misidentified subjects likely have other complicating conditions unidentified during screening. This is an advantage of the NEBA system.
NEBA doesn’t quite address the problem of diagnosing all types of ADHD, though it could aid the diagnosis accuracy for the inattention subtype.
There are similar technologies such as ANT as well as B-Alert from Advanced Brain-Monitoring aiming to accurately diagnose ADHD.
Treatment
Conventional
Treatments aim to shift underlying neural differences, the source of ADHD.
A more biological approach is to directly influence neurotransmitters through medication e.g. Ritalin, Concerta, Adderall, Vyvanse.
Medication is a subject of complaint: Patients and physicians essentially guess and check which medication and dosages work for them. And there are side effects e.g. weight gain, irritability, tearfulness etc.
On a higher level, patient habits can be shifted in processes of Cognitive-Behavioural Therapy and meditation.
But this extensively relies on the patient’s intentional cooperation and could be slow in changing the imbalances that cause the problem in the first place.
Can BCIs find the best of both worlds?
Gadi Schwartz, an NBC correspondent with ADHD, starts his day playing games on a difficult level for 8 minutes to set a focused mood for the day.
Gaming is in fact an existing brain training modality: The AtentivMynd solution for children with ADHD uses a gaming tablet along with an EEG headset.
The child can train in 1 of the 13 major intrapersonal skills, such as attention and self-regulation. The correct state detected by the EEG headset will cause the game character to run forward.
Among 337 children with ADHD, 83% had more than 25% symptom reductions. No side effects associated with medication were reported, though 6% of children reported motion sickness, eye strain and related side effects.
This accuracy is limited by the neuroscientific understanding of the individual patient, sensor placement and signal quality. Side effects can be attributed to the game design and possible communication latency between the headset and the protagonist’s movement which are fixable.
Brain Stimulation
Now, focal areas of the brain, pathways to these areas and even the entire brain can be stimulated. Techniques can range from using magnetic fields to weak/strong currents and ultrasound.
This picture shows the subject being stimulated via a weak electrical current on the forehead, namely the trigeminal nerve. The impulse then travels to frontal brain regions — key in controlling attention — and the brain stem to tune the excitability of neurons.
This device is called Monarch eTNS and is the first non-drug treatment approved by the USA Food and Drug Administration (FDA) (in 2019). The child can wear the device 8 hours each night for 4 weeks and experience improvement in symptoms.
Likewise, NeuroAudit from Israel uses ultrasound in a closed-loop (without delay) AI monitored stimulation. The system tracks and adapts stimulation according to the specific user throughout the course of treatment.
These stimulation techniques usually have no side effect, though the main weakness is, as the patient’s brain isn’t imaged, the electrode placement can be off. A slight move could cause another set of neurons to be inhibited or activated.
All of this means…
As neuroscience understanding progresses, ADHD diagnosis will increasingly gather data directly from the brain. The treatment using BCIs will likely use a combination of shifting fundamental neural structures and people’s habits.
