Neuroscience behind communication

March 2, 2021

We have just started a new series talking about language. At this historical pandemic moment, with many people living in social distancing, the available alternatives for the personal interchange have been defying our communicative capacity. Who has not seen a written message to be misinterpreted because the words have not been enough to express irony, rhythm, or affection? Communicating is about transmitting and recognizing the symbols and signs socially constituted that color and imply feelings to the transmitted content, exceeding words. Therefore, speaking about language is to argue the own interactive necessity and the social character of our human being condition.

Language for living in society.

In an evolutionary perspective, some theories suggest that the development of the language has happened to the detriment of other abilities. In other words, some abilities of our ancestors had been reduced or extinct throughout history to give place to our capacity of communication. According to these theories, when our ancestors had gone down the pantries of the trees and started to live in the ground, they had had to act in group to survive to the new threats, what had caused the necessity of communicating between them. In this way, we should have dispersed the capacity of detecting with precision and speed missing targets within a visual field to acquire the capacity of transmitting and receiving information.

From there on, this capacity has suffered refinements following the social evolution of the structures and relations complexity and the enlargement of the human being activities. Implicit or explicit, social norms determine the communicative rules, establishing ways of communicating not only verbally speaking or writing, but also physically, by means of gestures, face expressions, behaviors, and the own clothing. The refinement in this language process has also imposed larger complexity to the cerebral systems responsible for the performance of the communicative function.

Development of the Brain

A child, although endowed with all the necessary apparatus to the development of its communicative capacity, will only be able to develop this ability if exposed to the language itself. Beyond that, the capacity of communicating in an ample sense, not only by speaking, foresees the dialogue. The interaction with other individuals of the same species allows us to interpret adequately face expressions, gestures and other signs and symbols for then to reproduce them with communicative intention. But when did we start to develop the communicative capacity?

Language can be understood as usage of complex systems of communication. We develop the capacity of expressing ourselves verbally between the second and the third year of life, from changes derived from the development of the brain. Since our birth we are endowed with almost all the neurons that we will carry throughout the life, but from the 15 months on a significant increase of the dendritic density occurs, that is, in this age band an increase of the number of dendrites in the neurons happens- that is just the responsible part for the communication between the nerve cells. This means that almost everything we understand by brain development in this phase of life is related to the proliferation of the connection between neurons. The most important changes that occur from the second year of life are related to the language responsible areas.

Practically all the cerebral regions are, in some extent, implied in the functioning of our communicative capacity. This is because it involves emotional aspects (from the choice of our clothes to the way we gesture, many traces of our personality communicate our emotional condition), requires the activation of several sensory memories’ modalities (visual, hearing and scent) and depends on the integrity of innumerable other brain functions, some more primitive, others more evolved. These associations disclose the level of complexity of our communicative capacity and the requirement in terms of brain development and cognitive maturing so that we can adequately perform this function.

The development process of the structures responsible for the language is only complete around the age of 12 - except for the linguistic repertoire, of course, once our “internal dictionary” remains in construction throughout our life. Basic capacities for the acquisition of the language are inherent to the biological structure of the human brain, which explains the fact that there is regularity in the period of acquisition of the capacity to understand and express verbally in almost all the languages. Summing up: the human brain is prepared to learn and to use the language, since he is endowed with the necessary biological apparatus to exercise this function. But the development of the language also foresees a social component. After all, what is it for developing the ability to communicate if there will not have an interlocutor?


Marina von Zuben is neuroscientist, professor, and researcher at Hospital das Clínicas of USP, and Chief of Neuroscience and Learning of the Bossa. etc