The electrical activity of the neurons that populate the human brain is part of the basis of all thoughts, feelings and the acts we perform. That is why it is so difficult to understand what neurons do in each moment; everything that makes up our mental life consists in that inexplicable jump that goes from the frequency with which the neurons send electrical impulses to the transformation of this so simple in mental processes in all their complexity.
That is to say, there is something in the way of coordinating these nerve cells that make sensations, thoughts, memories , etc. appear.
Of course, it is still very far from understanding in a detailed way what kind of electrical signals in a part of the brain produce such thinking in a specific person and at a specific time, but there is something that is known about the functioning of the organ of the mind; it depends on something that is known as neuronal oscillatory activity , that is, firing frequencies of electrical impulses that generate what is known as the different types of brain waves .
The oscillations in neuronal electrical activity
The concept of oscillation in the activity of neurons refers to the different rhythms and frequencies that the electrical activity expresses in the central nervous system. This idea is very broad, and applies both to refer to what makes an individual neuron as a group of neurons working in networks.
For example, oscillation can refer to the degree of electrical activation of a single neuron over time, measuring the rate at which the appearance of a nerve impulse becomes more likely depending on the degree of depolarization ; but it can also be used to refer to the frequency with which several neurons in a group send signals almost simultaneously.
Be that as it may, in all cases these oscillations in electrical activity can be represented by waves by means of encephalography, in a similar way in which the beating of the heart is measured by the electrocardiogram.
The types of brain waves
As we have seen, the activity of neurons in the brain is not absolutely chaotic, but follows a very complex logic in which you can see how different neurons fire electrical signals at almost the same time in a continuous way.
This frequency, constituted by the activity of several neurons, forms what is known as brain waves , activation patterns that, unlike what occurs with the frequency of activation of a single neuron, are powerful and clear enough to be registered. placing sensors outside the scalp (through encephalography, one of the most used technologies in research on the nervous system).
In turn, brain waves can be classified into different types according to their frequency , that is, the time that passes between the moments when many neurons fire electrical signals at the same time.
These types of brain waves receive in the name of Delta waves, Theta waves, Alpha waves, Beta waves and Gamma waves.
1. Delta waves (1 to 3 Hz)
Delta waves are those that have greater wave amplitude , that is, that their frequency is very low. They are characteristics of the phase of deep sleep, which is the one in which we rarely dream. However, representing the activation patterns of this phase of deep sleep does not mean that the brain is relatively turned off. Although it is in a state of rest, it is no longer activated, but it is occupied with processes that do not depend on being in a state of consciousness.
2. Theta waves (3.5 to 7.5 Hz)
After the Delta waves, the Theta are those that present a greater wave amplitude. You are associated with the states of deep calm , relaxation and immersion in memories and fantasies, and also with the stage of REM sleep, which is the one in which we dream. Therefore, when these waves appear, it is estimated that there is consciousness or that it is very likely that there is, although it is a consciousness disconnected from what happens around us and centered on imaginary experiences.
3. Alpha waves (8 to 13 Hz)
Alpha is a type of brain wave that is more frequent than theta, although it is still related to states of relaxation. For example, they may appear during walks in a park, lying on a beach or watching television . Thus, they are not typical of the dream state, but of deep calm, an intermediate step.
4. Beta waves (12 to 33 Hz)
In Beta waves neuronal activity is intense. They are related to actions that require staying in a certain state of alert and agile attention management , such as a speech before a broad audience, the process of answering an examination question, etc.
Thus, this type of brain waves is linked to an agile handling of the focus of attention, depending on the objectives, and with concern for what happens in the present, usually around us, since we must react quickly to possible unforeseen
5. Gamma waves (25 to 100 Hz)
These are the type of brain waves with a greater frequency and smaller amplitude. They appear in waking states and it is believed that their presence is related to the appearance of consciousness , with the expansion of the attentional focus and memory management.