BIOFEEDBACK: WHAT IT IS FOR AND HOW IT WORKS (TECHNIQUES) - DUDAS - 2024

The Biofeedback is a therapy that is used to control the functions of the body, through the feedback system that has our body. It could be considered as a learning technique, widely used in the discipline of psychology.

Our body continuously performs an infinity of functions both automatic (such as breathing, blinking, circulating blood, etc.) and voluntary (walking, looking, raising our arms…).

All these functions do not go unnoticed by our brain, since it is our mind that controls all our actions. On the one hand, our brain is in charge of “starting” all the functions that our body performs.

On the other hand, our brain receives information about the state of the function that is developing. That is, our brain is responsible for sending the necessary information to our body to perform any function, and in turn, our body sends information to our brain about the development of those functions, so that it knows what is happening.

Well, it is this last point, the collection of information that the brain does about the state of the functions that are carried out in our body, what we understand as feedback, and on which the biofeedback technique is based.

Definition of biofeedback

Biofeedback could be defined as a technique that aims to control, voluntarily and consciously, a function that our body performs automatically. This voluntary control over function is done through our brain's feedback system.

So far, despite not having delved into how this technique works, I think the concept that biofeedback works is becoming clear, which is the following:

Use the feedback information that our mind has on the functions of the body, to be aware of physiological changes in our body that normally go unnoticed, and acquire a greater capacity to control certain functions.

What is it for?

With biofeedback training, it is possible to acquire a type of learning with which it is possible to consciously control physiological functions that are considered uncontrollable, or that are beyond voluntary control.

By doing this training, you are actually training yourself to improve your health, since you learn to control processes such as sweating, muscle tension or blood pressure.

The fact of being able to control these types of functions allows you to have a greater facility to reach a state of relaxation when you are overexcited or stressed, as well as to regulate the involuntary functions of your body when you feel discomfort, and thus reduce it.

And what is the best of all?

Well, each physiological change is accompanied by a change in mental and emotional state. So when you are anxious you have a series of thoughts, an emotion of overexcitement or stress, and physiological changes such as increased heart rate, sweating or pupillary dilation.

In this way, when you control your physiological changes, you are also controlling your psychological and emotional state. That is to say: you carry out a psychological therapy in reverse!

Differences with psychotherapy therapy

Normally psychotherapy works on your mental state, thoughts, cognitions, emotions and behaviors, to eliminate the alteration and thus also eliminate the physiological symptoms that it produces in your body.

Biofeedback training instead, what it does is allow you to learn to control the physiological states that occur in your body, so that by changing these, it is your psychological state that is benefited.

Therefore, it is not surprising that biofeedback is a technique that is applied in very diverse areas of both medicine and psychology.

In the field of psychology, it is effective in treating disorders such as phobias, neurosis, anxiety, stress, depression, ADHD, eating disorders or insomnia, among others. As well as in the training of elite athletes to control their activation and relaxation while they compete or train.

In the medical field it is used mainly to treat asthma, chemotherapy side effects, chronic pain, hypertension, constipation or incontinence.

How does biofeedback work?

First of all, it should be noted that each biofeedback session will be different, since it is a personalized therapy. The same biofeedback training cannot be useful for everyone.

The training will be in one way or another depending on the aspects that the patient wants to treat, and the stage of training in which they are.

Therefore, if you decide to go to a specialist for biofeedback training, it should not surprise you that the therapy begins with an initial interview, where you must explain both your medical history and the problems you want to treat with therapy.

Likewise, this first interview will also be useful so that the therapist can explain in detail the type of training that you will carry out, what each session consists of, how long the intervention will last and what delicate situations we could find ourselves.

Having clarified this, now we can go to see what a typical biofeedback training session looks like, which despite being able to vary in each case, contains 6 basic stages. They are as follows:

Signal detection

The first phase begins with the detection and measurement of the signals that our body produces.

To measure the signals of the functioning of our body, electrodes are placed on the body, which will be in charge of detecting them and transmitting them to the biofeedback device.

In this first detection phase we can choose between two types of techniques:

• The invasive, in which the electrodes are inserted into the subject.
• Non-invasive ones, in which the electrodes are placed on the surface of the skin.

But what signs are we detecting?

Well, it depends on what we want to treat. In this first phase of training, we can use 3 different devices depending on the functions of our body that we intend to measure.

• If what we want is to obtain information about the somatic nervous system, the instrument that we will use will be an electromyogram.
• If what we want is to record and measure the responses of our autonomic nervous system, we will use blood pressure control.
• And finally, if what we collect are the functions performed by our central nervous system, we will use the electroencephalogram .

This first phase of training, which only involves the use of various devices to quantify the records of our bodily functions, allows us to obtain all the information necessary to define the type of biofeedback training to be carried out.

Once the signal is registered, a series of actions are carried out to convert the signal produced by the body into a stimulus that is capable of producing the same action as the signal, and that can act as feedback during training.

The first of all is the amplification of the signal, then the processing and the filter will come, and finally the conversion.

Signal amplification

The physiological signals that we have collected through the different instruments are processed and analyzed by the biofeedback apparatus. However, in order to analyze the collected signals it is necessary to amplify them.

Thus, the magnitude or intensity of the response collected is magnified in a controlled way, with the least possible distortion, in order to perform

its analysis.

Signal processing and filtering

Once the signal is amplified, it must be filtered. What does this mean?

Very simple: Normally, the signals that we can register from our body (blood pressure, muscle contraction, electrical activity of the brain, etc.) are not pure, since they may have been captured by other different potentials, unrelated to the signal with which we intend to work.

To do this, the signal captured with the electrodes is filtered through different frequency ranges. Once the signal is filtered, it is processed.

The processing consists of converting the internal signal of the organism that has been registered in the biofeedback device, into visual, auditory signals or direct information to the subject.

To do this, there are two techniques:

• The integration: consists of simplifying the feedback signal. It is carried out by accumulating sets of isolated signals that are produced in a certain period of time, with the aim of converting them into a single signal that can function as a representative of the entire set of signals.
• The response threshold: with this technique, the provision of information or feedback to the subject is carried out only when the signal exceeds (either above or below) a certain amplitude previously established.

Conversion to auditory or visual cues

In this phase, the signals that have already been processed are finally transformed into a stimulus that can be perceived and evaluated by the patient.

The objective of this stimulus is that it is capable of producing the physiological function that we have registered, and with which we want to work.

Goal setting

Once we have the physiological signal converted into a stimulus, it is time to set the training objectives. In this phase then, it is determined what is intended to be achieved with the training, and what are the objectives both in the short and long term.

Setting these goals is essential to be able to carry out an adequate follow-up of the training, and to quantify if the procedures and processes carried out are adequate to the objective.

Biofeedback training

We finally reached the important phase of the intervention. The training itself.

In this phase, the measuring devices used at the start of therapy will be reconnected. However, now we will not just lie down while the machine works.

And it is that during training, the signals that our body sends to our brain, will reach us through the stimuli that have been made previously.

That is to say: the stimuli that the expert has prepared will be presented to us. These stimuli can be:

• Visuals: movement of a needle, series of colored lights, images, etc.
• Auditory: tones that vary in frequency and intensity.

In addition, the stimulus can be presented in different ways:

• Proportionally: feedback varies proportionally throughout the entire response range
• In a binary way: the stimulus has two states, and one of the two is presented based on previously established criteria.

The objective of this training is that little by little, we learn to control our physiological responses to stimuli.

At first our physiological response to the presented stimuli is a concrete response. However, through the systematic presentation of these stimuli, you learn to control your physiological response, a fact that you were previously unable to control.

As while the stimuli are being presented to us, the devices are registering our response, we can gradually objectify our physiological responses, and our progress in training, a fact that will help the therapist to redefine the exercises in the following sessions.

It is possible that the therapist will ask you to carry out some type of activity at home, with the aim of extending the skill outside the consultation, even in advanced phases, it may be that he will teach you to use the devices, in order to be able to to do the solo training.

References

1. BIOFEEDBACK: from behavior modification techniques, applied to mental problems, to intervention techniques for physical problems HERNÁN

   ANDRÉS MARÍN AGUDELO AND STEFANO VINACCIA ALPI.

2. Evidence-Based Practice in Biofeedback and Neurofeedback. Carolin Yucha and Christopher Gilbert.
3. Conceptual review of Biofeedback. By Mariano Chóliz Montañes and Antonio Capafóns Bonet. University of Valencia.