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What is neurofeedback? What is biofeedback? And how does a neurofeedback session actually work? - An overview of the most important terms in Neurofeedback

13. October 2023

Neurofeedback is becoming more and more well-known and many terms are becoming more common. But what do they actually mean? We would like to explain the most important of these terms in this blog post. 

What is Neurofeedback?
Neurofeedback is a computer-assisted therapy method for clinical use, in which selected parameters of one's own brain activity are made perceptible. For this purpose, brain waves are measured in real time on the surface of the head (neuro), which influence an audiovisual animation, often similar to a computer game (feedback). Neurofeedback is like a kind of mirror for the brain. Direct feedback based on proven treatment protocols and electrode positions aims to improve the brain's ability to self-regulate. In this way, symptoms of diseases can be alleviated.

What is Biofeedback?
In Biofeedback, peripheral physiological parameters are measured and fed back to the screen as feedback. The parameters can be, for example, respiration, heart rate variability or skin conductance. The feedback can be used to draw conclusions about the patient's current stress level. Biofeedback can be used in the therapy of mental and physical illnesses, as well as in performance and concentration training. Especially in symptom-based ILF - Neurofeedback, Biofeedback can be a good complement. Especially for patients who are not able to perceive or verbalize changes in their state of stress or relaxation well, Biofeedback is a way to better perceive and experience the changes. It can also be beneficial for therapists. For example, skeptical patients can be made aware of the connection between psyche and physiology. Therapists can also derive signs of stress and relaxation and optimize therapy accordingly.

How does self-regulation work in Neurofeedback?
In Neurofeedback, the brain's ability to self-regulate is trained. For this purpose, EEG signals are derived from the surface of the head. Based on a thorough survey of the symptoms of the person being treated, specific frequency ranges of brain activity are measured and evaluated to control feedback in real time in the form of an animation on a screen. The brain "recognizes" that it can influence the animation and, for example, the image becomes clearer and sharper or the music louder and softer. Through this continuous process, the treated persons can learn to improve their self-regulation ability. Especially in the case of mental illnesses, often associated stress symptoms, sleep disorders or disturbances of the attention and concentration spectrum can be significantly improved in this way. It is important to know that there is no optimal frequency that is the same for every person. Instead, the optimal frequency is very individual and depends on both the person and the given situation. Through self-regulation, the brain learns to find the optimal arousal frequency for itself in order to avoid over- and under-excitement, as well as associated symptoms.

Heart rate and heart rate variability in Biofeedback.
The pulse is a biological parameter that changes according to external and internal demands. Not only a steady pulse, but also the adaptability of the heart rate to different demands - the so-called heart rate variability (HRV) - is a central parameter in Biofeedback. 
Heart rate variability is the variation of the time interval between two heartbeats (also: beat to beat interval). This is longer in times of relaxation than in times of physical or emotional stress. A high heart rate variability speaks for a good (peripheral) self-regulation, because it indicates that the organism is able to adjust the heart rate depending on the requirements and finds the optimal frequency for the respective situation. Low heart rate variability is often related to a problem in dealing with stressful situations, memories or stress in general. Especially for patients with anxiety disorders, depression or chronic pain, Biofeedback with heart rate variability training can be helpful. Often these patients are not aware of the connection between their emotional stress and physical reactions and the perception of their own body does not work well because they have a permanently very high stress level. Training here to perceive, influence and synchronize central parameters such as heartbeat and breathing and thus lower the general stress level can be a key experience in therapy and make patients aware that they do have control over their physical and psychological state.

Breathing in Biofeedback
You probably know the tip that lay literature and grandmothers like to give whenever someone is stressed: take three deep breaths. Does that really help? Here's a little experiment: put your hand on your stomach. Breathe deeply into your belly, feel how the hand rises, how your belly bulges, when the belly is bulging to the maximum, hold your breath for a moment and then breathe out again slowly and evenly. Feel the air flowing first out of the belly and then out of the tops of the lungs, over both lungs and out the airway. Repeat this three times. What do you notice? How are you conducting yourself? How has your heartbeat changed? The Heartbeat?! Exactly - breathing and heartbeat are physiologically closely related. In a relaxed state, heart rate and breathing rate correlate, this is also called "respiratory sinus arrhythmia". When breathing in, the heart rate thereby becomes higher, the sympathetic nervous system is activated, and when breathing out, the heart rate becomes lower, the parasympathetic nervous system is activated. Breathing deeply in and out three times in stressful situations can thus help not only to gain better awareness and control over one's own breathing, but subsequently also to synchronize the correlation of breathing and heartbeat.

What is actually the skin conductance?
The skin on the palm of our hand is characterized by a particularly large number of sweat glands. In times of high stress, the glandular activity also increases rapidly. Since sweat is a salty liquid, the skin conductance increases as a result. This is measured by two electrodes on the fingers. In healthy people, skin conductance is constant and low at rest. If the skin conductance increases due to the presentation of a stressor, it usually returns to its initial level after 1 - 2 minutes. If the value remains at a high level for a long time, this indicates problems with emotional regulation. Fluctuations without any apparent reason can indicate that even stimuli that are actually neutral are perceived as stressful. Since skin conductance responds quickly to stressful stimuli and is easy to measure, it is particularly well suited as a psychophysiological mirror in therapy - and reflects the change between tension and relaxation. However, it can also be used as a support in relaxation training or in learning various relaxation techniques.

The body temperature in Biofeedback
Temperature is usually measured by a sensor on the finger. In a relaxed state, the smooth muscles in the walls of the blood vessels usually also relax, which causes more blood to flow into the extremities - we often recognize this by the feeling of warmth in the hands. Thus, an onset of relaxation is accompanied by an increase in temperature in the extremities. Under stress or tension, the muscles in the vascular walls contract, the vessels become narrower and less blood reaches the extremities, often resulting in a drop in body temperature. The body temperature usually reacts somewhat delayed, from the beginning of the stress reaction to a drop in body temperature in the extremities may well take 1-2 minutes. The body temperature skin conductance can be used in therapy, for example, to demonstrate the influence of thoughts and ideas on physiology, in fact some patients succeed in achieving a change in temperature by imagining warmth/cold, and body temperature can also play a role in relaxation training.

The combination of Biofeedback and Neurofeedback
In symptom-based infra low frequency (ILF) Neurofeedback, the patient's symptoms and state changes are the central components. Many of these symptoms also relate to correlates of stress and relaxation. Accordingly, the addition of Biofeedback parameters can be a useful complement to ILF Neurofeedback. This makes it possible for patient and therapist to include the physiological correlates of state changes in the therapy. Patients who are not able to perceive or verbalize changes in their stress and relaxation state very well will get another possibility to experience changes through Neurofeedback. Even changes that are partially below the threshold of perception can be made visible by measuring peripheral signals and can be incorporated into the therapy. For skeptical or tense patients, the inclusion of Biofeedback parameters in the sense of psychoeducation can also help to make the connection between psyche and physiology visible and tangible, to familiarize the patient with the setting with electrodes, and to gradually reduce the possible fear of changes through therapy in order to gently introduce the patient to Neurofeedback. The therapist can deduce signs of stress and relaxation in the physiological parameters and optimize the therapy accordingly, for example by changing the frequency.

What is Alpha-Theta Neurofeedback/ Synchrony Training?
Alpha-Theta Neurofeedback and Synchrony Training are two special types of neurofeedback. Alpha-Theta Neurofeedback is mainly about calming down cortical activity and being able to "shut down" better, both physically and psychologically. We like to call the synchrony training "mindfulness training" guided by one's own brain activity. Both methods ideally complement ILF neurofeedback and are used especially for post-traumatic stress disorders, anxiety and sleep disorders, but also in peak performance.