What is Neurofeedback Training?
Neurofeedback training is a training of the brain where the brain learns to flexibly switch between different arousal states and learns how to maintain certain arousal states, such as relaxed attention or a relaxed resting state, even over a longer time span, if needed. It can be seen as training the capacity of the brain to self-regulate.
As the word training implies, several training sessions are needed to reach a lasting effect (mostly 20-40). What an entire training- or treatment plan looks like can be seen on the page Neurofeedback Therapy.
The following describes how a training session is performed.
Preparation of the training
For most training protocols the so-called 1-channel recordings are sufficient. That means that only one channel of the EEG amplifier is used. In this case three electrodes are fasted to the head of the patient with appropriate adhesive and conductive pastes. Two of the electrodes are the active measurement electrodes, one electrode serves a a ground electrode. The therapist decides over which brain regions he must fasten the electrodes for the training.
Next, the impedance must be checked. This means, the therapist checks if the conductivity between the electrodes and the skin of the head is high enough to get a good electrical signal. The changes in potential that can be measured at the surface of the skull, reflect how the brain regulates it´s own state of arousal. This can be measured as small potential fluctuations in the microvolt range on the surface of the skull. Compared to the prevailing electrical noise in most rooms with electrical supply, these potential fluctuations of the brain are very, very small. Therefore the electrode contacts and the amplifier technology must be very good in order to be able to measure the brain activity despite the background noise.
The actual Neurofeedback Training
During the training the patient sits in a comfortable chair in front of a patient monitor. The therapist sets the relevant parameters on the therapist screen that are filtered out of the EEG and reported back to the patient via the feedback.
The feedback can be tailored to the preferences of each patient. Mainly, the patient should regard the feedback as pleasant. The patient can choose between different options. Mostly these are animations, similar to computer games, where the patient controls up to 17 different feedback parameters with his or her brain activity. That can be the speed of a car in a car race, of a jet ski on the water, of a rocket in a tunnel, trains or other options.
A very popular feedback is the video feedback of the Advanced Media Player. Here the played videos are altered by the brain activity. For example, the picture becomes bigger or smaller, sharper or blurrier, or the audio signal becomes louder or less loud, the picture darker or brighter, all acording to the brain activity.
The patient should not try to consciously influence the feedback. The purpose is only to reflect to the brain the momentary changes. As a result, the brain receives aditional information that it normally does not have. The brain integrates this information into it´s own control loops and unconsciously learns to alter states.
The patient perceives these changes and reports them to the therapist. For example, the patient can become more relaxed during the training session or more awake or alert. The patient can also experience a reduction of some symptoms during the training. Some patients experience changes during the session, others only after the session or after several sessions.
The therapist will continuously ask for changes specifically during the session and adjust the parameters in the software accordingly. Feedback animations can be changed during the session. In order to involve the patient more in the feedback, there is the possibility to control specific parameters of the feedback by a gamepad. For example, the velocity of the car, the brightness of the sky, the volume of the music are controlled by the brain and the direction of the car is controlled by the game pad.
During the session different regions of the brain can be trained. The therapist then changes the electrode positions during the session.
Completion of the training
After the training session, that lasts from 30 to 50 minutes, the electrodes are removed and the hair is cleaned from the conductive paste.
The patient is then instructed to watch carefully for changes after the training and to report them at the next session. In the next session it is decided if the training is repeated in the same way or if the training parameters have to be adjusted or additional areas of the brain must be trained.