The production of language is the ability of the human being to communicate by means of that system of symbols called language. This faculty has been fundamental in our evolutionary history. The ability to communicate effectively has made collaboration and the creation of complex societies possible, with greater chances of coping with a hostile world. For this purpose, there are biologically rooted nuclei in our brain such as Broca’s area.
A key aspect in the neural arrangement of language is its lateralization, that is, the vast majority of structures related to the production of language are found in the left hemisphere; it is true, however, that according to some studies, processes such as joking, pragmatics and sarcasm are managed by the right hemisphere. Broca’s area, responsible for the production of language, is therefore located in the left hemisphere, precisely in area 44, according to Brodmann’s subdivision into areas.
In this article we will talk about two fundamental aspects that help to understand the involvement of the Broca area in language. The first is the anatomical and functional aspect. The second concerns Broca’s aphasia, as a consequence of injuries in this area.
Broca’s area: anatomy and physiology
Over time it has been discovered that not only Broca’s area is involved in language production. In addition to Brodmann area 44, areas 45, 47 and a large part of 46 are involved. It would therefore be more correct to speak of Broca’s system, which includes all the areas responsible for the production of language.
Within the Broca system we can find a further subdivision into two large structures: (a) triangular and (b) opercular. The triangular portion is located in the anterior part of Broca’s area, the opercular portion is located in the posterior part. At the anatomical level, it is interesting to note the presence of important connections between this system and the Wernicke area; the latter is mainly responsible for understanding the language. The two areas (Wernicke and Broca) are connected by a series of neuronal bundles, which in turn form the so-called arched fascicle.
The functions performed by the Broca area are as follows:
- Management of verbal behavior, both in oral and written form.
- Management of graphemes, phonemes and words, organization of grammar and morphology.
- Coordination of the speaking bodies to manage pronunciation.
- Adjustment of prosody, tone of voice and speech rhythm.
These functions are the basis of adequate language production and allow for good communication. Any injuries in Broca’s area, therefore, can have important repercussions on language production and communication skills. We see a direct consequence of any injury to this area.
Broca’s aphasia is a disturbance in the production of language of harmful origin. It is characterized by slow, strained and non-fluid speech. Although the pronunciation is often faulty, the message is usually endowed with meaning, so it can be concluded that in this disorder the semantic aspect does not undergo any alteration.
It is easier for people with Broca’s aphasia to utter some groups of words than others. For example, functional words (a, the, some, above, of) are more complicated to pronounce than the words that convey the content. This is mainly due to the fact that the former are of purely grammatical use (and the management of grammar is, in fact, the responsibility of Broca’s area). Since the semantic function is not touched, the content words are easier to produce.
Another key aspect of Broca’s aphasia is that understanding of the language remains intact. People suffering from this disorder have no problem reading or listening to spoken speech. The brain structure responsible for the understanding process is located elsewhere, in the Wernicke area. This helps us to better understand that Broca’s area specializes in language production ; although other areas are connected to it, they maintain their functions independently.
Finally, a curious phenomenon is what occurs when the areas in charge of language suffer a lesion at a very early age. Thanks to the great plasticity of the brain, if the left hemisphere is damaged, it is possible for language to be transferred to the right hemisphere. Thanks to this, brain lesions occurring before the tongue consolidation phase can be reduced, reaching normal or practically normal development.