[The origins of language: an analysis from the aphasia perspective]

Different areas of knowledge have contributed to a better understanding of the origins of human language. AIM. To relate our current knowledge about the origins of language with the language pathology found in the case of brain injuries (aphasia).

There are two fundamental forms of aphasia, which linked to defects in the lexico-semantic and grammatical systems of language (Wernicke-type aphasia and Broca-type aphasia, respectively). From observations made on children's development of language and experiments with primates, it has been shown that language initially appears as a lexico-semantic system. Grammar correlates with the ability to represent actions (verbs) and depends on what is known as Broca's area and its related brain circuits, but it is also related to the ability to quickly carry out the sequencing of the articulatory movements required for speaking (speech praxis).

Language may have appeared as a lexico-semantic system much earlier than language as a syntactic system. The former may have developed around 200,000-300,000 years ago, coinciding with the increase in the temporal lobe, and would have existed in other hominids. Language as a grammatical system appeared perhaps as recently as 50,000 years ago and seems to be exclusive to Homo sapiens.