What is Neurofeedback for ADHD Impulsivity?
Neurofeedback is a form of biofeedback which uses EEG equipment to monitor a patient's brain-waves while simultaneously showing the results of those measurements to the patient on a display screen.
It might be useful to compare this technique to the biofeedback used by diabetics. Many individuals with diabetes use biofeedback to monitor their glucose levels throughout the day, and this enables them to see how meals and various activities impact their blood sugar. This information allows these patients to adjust their choices in order to maintain a healthy balance.
Instead of measuring glucose levels, patients with mental health conditions such as ADHD sometimes use brain measurements in order to monitor the state of their condition. When EEG information about their brain's activity is fed back into their brain (through the display screen), patients are able to associate internal mental states with EEG measurements of brain-wave activity.
EEGs Monitor Brain-Wave Frequency
Electroencephalograms (EEGs) are linked to the brain through electrodes which are placed on the scalp of the patient. EEG equipment monitors the electrical activity recorded by the electrodes (the brain-wave frequencies) and presents this data on a display screen.
Various brain-wave frequencies have been identified with certain cognitive processes and levels of alertness. For example, theta brain-waves range between 4 – 8 Hz and are associated with inactive areas of the brain or a brain-state that is spacey and unfocused. These are close to delta brain-waves, which range from 0.5 – 3.5 Hz and are usually found in patients who are asleep.
Toward the other end of the spectrum, alpha brain-waves (8 – 12 Hz) are generally identified as a relaxed brain-state which is able to begin working when needed. Beta brain-waves range from 13 Hz to about 30 Hz, and are associated with increased states of alertness, focus and concentration.
(An example of a theta frequency is shown to the left. Compare this to a beta frequency, as depicted to the right.)
Impulsivity May Be Localized
The important thing to keep in mind is that these brain-wave frequencies are localized, meaning that they can vary between different parts of the brain at the same time. For example, if you go into a completely quiet room, there will be less activity in the auditory cortex, but this does not mean that your overall brain-state is sleepy or unfocused. It would just be that the area of your brain which processes sound is inactive at that moment.
While there is still much more to be learned about this complex subject, there is a growing body of research which suggests that the frontal cortex is the area of the brain which is most significantly impaired in patients with ADHD. Shown here, the frontal cortex is thought to be particularly important in impulse control. When this area of the brain demonstrates lower-frequency brain-waves, it is usually a good bet that the patient is more prone to impulsive decision-making.
Why Use Neurofeedback for ADHD Impulsivity Treatment?
The reason why neurofeedback is being used to treat impulsivity is that this technique may be able to help increase activity in the frontal cortex (and other relevant areas), thereby decreasing symptoms of ADHD impulsivity. For example, a doctor might use an EEG to look at an ADHD patient's brain and say: "I'm sorry Johnny, but it looks like you have an impairing level of theta frequency brain-waves in your prefrontal cortex. We might be able to change them to beta frequency waves if we use neurofeedback effectively, and that should help you to be less impulsive."
The patient might then begin a neurofeedback treatment program which employs operant conditioning in order to reduce impulsivity.
Neurofeedback and Operant Conditioning
Doctors treating ADHD impulsivity with neurofeedback in this way will monitor the areas of the patient's brain which are associated with impulse control. They attempt to help the patient form positive associations with brain activity which corresponds to better impulse control and negative associations for activity which corresponds with greater impulsivity.
The example given by Katherine Ellison, author of Buzz: A Year of Paying Attention, is of a field which becomes more or less pleasant based on the patient's neural activity. As she explains in a New York Times article: "If your brain behaves as desired, you’ll be encouraged with soothing sounds and visual treats, like images of exploding stars or a flowering field. If not, you’ll get silence, a darkening screen and wilting flora." (Ellison, 1)
Translating the brain-wave frequencies into these more human sensations may make it easier for patients to create these associations. Our emotional circuitry is more easily engaged with unpleasant noises and images than with a theta frequency graph, and an engaged emotional circuitry makes for easier and stronger memory (association) formation.
The hope is that these associations will stay with the patient after sufficient neurofeedback treatment sessions, so that when the patient's frontal cortex begins to dip into theta frequencies outside of treatment, the negative associations will still be brought up. This should encourage the patient to change their mental state in such a way as to induce beta frequencies (as well as the positive associations). This should result in a mental state which is better able to control impulsiveness.
Problems With Neurofeedback for ADHD
Neurofeedback was first used as a treatment for ADHD in 1976. Despite this fact, it has been a controversial technique throughout most of the three-and-a-half decades which have passed since this first ADHD application.
There are many reasons for this, but two of the most important ones are 1) the frequency of sensationalist claims made by less scrupulous clinicians and 2) the lack of rigorous scientific evidence in favor of the effectiveness of ADHD applications of neurofeedback.
The sensationalism is somewhat unavoidable with new technologies, but this source of controversy has declined as greater numbers of more sober-minded scientists and doctors have begun taking a careful look at this approach to ADHD treatment.
Effectiveness of Neurofeedback for ADHD Impulsivity
The more serious issue with neurofeedback treatments is the general lack of rigorous studies within the literature which demonstrate its effectiveness. For example, past studies of neurofeedback for ADHD have been criticized for problems such as: lacking proper control groups, confounding the effects of different treatments, lacking placebo controls, and failing to use blind evaluators. (Loo & Barkley, 69)
It is not that studies show that neurofeedback is ineffective in treating impulsivity or other ADHD symptoms. It is that the studies which have been carried out were generally not methodologically strong enough to validate either conclusion.
Despite this deficit, creative scientists are teaming up with benefactors such as the National Institute of Mental Health in order to devise and execute studies that circumvent some of the limitations of previous work.
In a meta-analysis of some of the best research on neurofeedback treatments for ADHD, it was found that impulsivity and inattention improved after a course of neurofeedback. There was a smaller effect size for neurofeedback treatment of hyperactivity. (Arns, et. al., 2009) Other individual studies and meta-analyses are finding similar results, but only further investigation and debate will lead to strong conclusions about the effectiveness of neurofeedback treatments for ADHD symptoms such as impulsivity.
Arns, Marjin, et. al. "Efficacy of Neurofeedback Treatment in ADHD: The Effects on Inattention, Impulsivity and Hyperactivity: A Meta-analysis", Journal of Clinical EEG & Neuroscience, 2009, Vol. 40, No. 3, pp. 180-189.
Ellison, Katherine. "Neurofeedback Gains Popularity and Second Looks", https://www.nytimes.com/2010/10/05/health/05neurofeedback.html?_r=2.
Hamilton, Jon. "Train The Brain: Using Neurofeedback To Treat ADHD", https://www.npr.org/templates/story/story.php?storyId=130896102.
Hammond, D. Corydon. "What is Neurofeedback?", https://www.isnr.org/uploads/whatisnfb.pdf.
Loo, Sandra K., and Barkley, Russell A. "Clinical Utility of EEG in Attention Deficit Hyperactivity Disorder", Applied Neuropsychology, 2005, Vol. 12, No. 2, pp. 64–76.
"New NIMH Research to Test Innovative Treatments for Children with ADHD", https://www.nimh.nih.gov/science-news/2008/new-nimh-research-to-test-innovative-treatments-for-children-with-adhd.shtml.
The International Society for Neurofeedback & Research, https://www.isnr.org.
"Biofeedback system diagram", Wikimedia Commons/(CC) Marek Jacenko.
"Dopamine Pathways", Wikimedia Commons/NIDA [Public Domain].
"EEG Beta", Wikimedia Commons/(CC) Hugo Gamboa.
"EEG Theta", Wikimedia Commons/(CC) Hugo Gamboa.