Understanding how the brain works requires years of learning, and despite that, the level of understanding we can have about this set of organs will always be very limited; It is not in vain that the human brain is one of the most complex systems that exist.
On the other hand, There are some ideas that help you get started by better understanding this tangle of concepts that serve to explain what this part of the nervous system is. These are some of these keys.
This is a list of ideas that I believe help to understand fundamental ideas about how the brain works I recommend reading them in order, because they are arranged from micro to macro.
1. Glia and neurons
A brain is, fundamentally, a set of neurons and glial cells. The latter are less known outside universities, but in reality they are much more numerous than neurons (which is quite impressive, considering that an adult human brain has around 80,000,000,000 neurons).
What is each of these cell types responsible for? Neurons are what create the flows of electrochemical signals that constitute mental processes; Basically, everything that psychology studies is reflected in the way in which neurons communicate with each other.
Glial cells, for their part, fulfill very diverse functions, and until recently it was believed that they are basically responsible for protecting neurons and facilitating their movement. However, in recent years, research has appeared that shows how glial cells have their own communication network and can influence how neurons relate to each other. That is to say, we are only beginning to fully understand its importance.
2. The role of synapses
When it comes to understanding how the brain works, knowing how the communication networks between neurons work is as important or more important than knowing how each neuron works individually, and that means that the points at which these nerve cells send information to each other. Among them they are of crucial importance for neuroscientists and psychologists. The name given to these areas is “synaptic space”, which in the vast majority of cases It is a small gap that opens between the cell membranes of the nerve terminals of two neurons: one of them is the presynaptic and the other is the postsynaptic.
In the synapses, the electrical signal that travels through a neuron is transformed into a chemical signal, that is, a torrent of substances that we call neurotransmitters and neuromodulators. These microscopic particles reach the nerve terminal of the other neuron and there, they are captured by structures called receptors. From that point, the torrent of chemicals received by the postsynaptic neuron has an effect on the frequency with which this nerve cell will emit electrical impulses that can have effects on other neurons.
This mechanism seems simple, but it really is not, because there are many types of neurotransmitters and structures that interact with them, and at the same time each neuron is usually connected to many others at the same time: they do not usually pass information to each other in a linear manner, as in the telephone game.
3. Software and hardware are indistinguishable
It is common to try to understand the brain as if it were a conventional computer, but this comparison is only justified in certain contexts, because it does not serve to capture the real functioning of the brain. And one of the main reasons why a brain is distinguished from a computer is the fact that in the former it does not make sense to distinguish between software and hardware. All the processes that are taking place in a brain materially modify the brain, and The structure of the brain itself is what causes neurons to send nerve signals: does not depend on programming codes.
That is why, among other things, the brain does not work with content that can be stored on a USB, as is the case with computers. You can try to interpret what happens in a brain in real time, and have this interpretation structured as a code that is understandable to us, but we will have invented that code; It does not arise from the brain. Which does not mean that it is impossible to know approximately what certain parts of the torrent of information that travels through a brain consist of.
From what has been said above, this other idea is derived: that the brain is changing all the time, no matter what we do Everything we perceive and do leaves a more or less intense mark on our brain, and this mark, in turn, will make everything that occurs from that moment on be one way or another. That is to say, our mental life is an accumulation of modifications, of neurons that tighten their ties and then loosen them depending on everything that happens to us.
This ability (or, rather, need) of our brain to constantly change depending on circumstances is called brain plasticity.
5. The role of attention
As much as the human brain seems like a prodigy of nature capable of doing quite impressive things, the truth is that the data set with which it works is always full of gaps. In fact, he is not even capable of properly processing all the information that is coming to him in real time through his senses, let alone remembering everything, something that only happens in incredibly exceptional cases.
What the human brain does is obey the principle of survival: what matters is not knowing everything, but knowing just enough to survive. Attention is the mechanism by which certain parts of the available information are selected and others are ignored. In this way, the nervous system is capable of locating elements of information that are relevant to focus attention on them and not on others, all depending on what our objective is. This mechanism is very useful, because in certain circumstances it makes us appear to be blind to things that happen in front of our noses.
This point follows from the previous section. Because the brain has a limited amount of “processable” information, there are some information gaps that it has to fill in without us constantly having to search for the missing information. For it, There are some automatic mechanisms that cover these gaps discreetly
An example is what happens with the part of the retina that gives way to the beginning of the optic nerve. This is an area in which the eye is unable to transform light signals into nerve impulses, and therefore it is as if we had a hole in the middle of our visual field. However, we do not realize that.
7. The parts of the brain always work together
Although the brain is made up of different anatomical areas more or less specialized in some processes, They all need to be well connected to each other to do their job well That does not mean that they all have to communicate directly with all the others, but that to function they must be wired with the “general network” of information that circulates through the brain.
8. The rational and the emotional go hand in hand
Although it is very useful for us to distinguish between the rational and the emotional in theoretical terms**, in our brain all the mental processes that we can link to one or another domain work together**.
For example, the parts of the brain most related to the appearance of emotions (a set of structures known as the limbic system) are those that set the objectives that we try to achieve effectively through action plans based on logic and that, of all In any case, they will continue to be influenced by emotional factors that will make the rationality of these strategies quite relative, even if we do not realize it.
