A kind of biofeedback, neurofeedback therapy denotes a non-invasive, pain-free procedure that seeks to help patients self-control involuntary brain functions, such as excessive activity driving anxiety, or deficient signals underlying attention deficits. It involves placing electrodes on the head, which measure brain waves in response to various audio-visual prompts while providing real-time feedback about how the brain reacts.
Eventually, by working with a professional, patients can understand the driving forces of these abnormal functional patterns, and better identify the root cause of brain dysfunction at the source of various neurological and psychological disorders. With practice, eventually they can learn to discern how the feel during different brain states and ultimately how to re-entrain brainwaves to the desired frequency and/or patterns; or avoid an undesired functional brain pattern, such as may be causing agitation, for example.
Neurofeedback therapy has proven helpful in diagnosing or treating various conditions, including anxiety, attention deficit hyperactivity disorder (ADHD), autistic spectrum disorders, depression, epilepsy, insomnia, and migraine. Each condition relates to a subtly different type of neurofeedback therapy. During each type, the electrodes attached to the patient’s head search for specific brain frequencies or the speed of brain waves emissions, indicating how the patient reacts. Different frequencies and patterns correspond to different brain functions or activity.
Medical practice has recognized seven types of neurofeedback therapy. These include frequency/power, slow cortical potential neurofeedback (SCP-NF), low-energy neurofeedback system (LENS), hemoencephalographic (HEG), live Z-score, low-resolution electromagnetic tomography (LORE-TA), and functional magnetic resonance imaging (fMRI).
The frequency/power neurofeedback is the simplest and most widespread type. Also called “surface neurofeedback,” it typically involves using up to four surface electrodes to modulate the speed of specific brain waves in certain brain locations associated with anxiety, ADHD, and insomnia. Besides helping people with ADHD and insomnia, LENS seeks to aid those with anxiety, depression, fibromyalgia, and restless leg syndrome. LENS does not necessitate patients’ conscious efforts. They lie down motionless with closed eyes while the electrodes attached to their head emit a weak electromagnetic signal to identify areas with low brain activity and eventually change the brain functions.
The SCP-NF seeks to aid people with ADHD, epilepsy, and migraines by influencing the direction of slow cortical potentials related to these conditions. Furthermore, a 2014 trial published in Frontiers in Human Neuroscience, a leading peer-reviewed journal, reports positive results using this type of neurofeedback for children with ADHD. While definitive conclusions require further research, the authors considered SCP-NF a promising alternative to the widespread pharmacological solutions. Furthermore, by harnessing the brain's neuro-plasticity, gains made with NFB are sustained much longer than the effect achieved through drug therapy.
The HEG and live Z-score types of neurofeedback specifically aim to help people with severe migraines and insomnia. With the first, the electrodes localize the blood flow in the brain. Then, using this feedback, work to increase it and thus, relieve the pain or minimize the reoccurrence of migraines. Live Z-score offers continuous feedback by continuously comparing variables of a patient’s brain electrical activity to a referral database.
LORE-TA uses 19 electrodes to monitor brain phases, power, and coherence. This neurofeedback type has offered multiple insights into where in the brain occur higher cognitive functions. Its main application is for treating patients with addictions, depression, and obsessive-compulsive disorder.
Finally, the fMRI is the latest addition to the types of neurofeedback. It uses the feedback from deep subcortical brain areas activity to map out the inner working of the brain and regulate its activity. All NFB employs the basic reward paradigm derived from operant conditioning: as the patient approaches and maintains the target brain wave patterns, they are given the 'reward' (this is the 'feedback') which typically comes in the form of triggering a movie to play.
