Abstract
In this paper it is emphasized that human language has two rather different dimensions corresponding to two different language systems: lexical/semantic and grammatical. These two language systems are supported by different brain structures (temporal and frontal), and based in different learning strategies (declarative and procedural). In cases of brain pathology, each one can be independently impaired (Wernicke aphasia and Broca aphasia). While the lexical/semantic language system may have appeared during human evolution long before the contemporary man, the grammatical language system probably represents a relatively recent acquisition. Language grammar may be the departing ability for the development of the metacognitive executive functions and is probably based in the ability to internally represent actions.
Highlights
It is usually assumed that throughout human history there is a continuous and progressive complexization of language [1,2]
In this paper it is emphasized that human language has two rather different dimensions corresponding to two different language systems: lexical/semantic and grammatical
The emergence of grammar in human evolution is not just a quantitative but rather qualitative change (e.g., [6]), probably associated with the emergence of the so-called metacognitive executive functions [7]
Summary
It is usually assumed that throughout human history (and during child language development) there is a continuous and progressive complexization of language [1,2]. The emergence of grammar represents the most crucial leap in human language evolution These two language systems (lexical/semantic and grammatical) are correlated with the activity of two distinct brain areas of the left hemisphere (temporal and frontal) (e.g., [8,9]); they are mediated by different learning processes (explicit and implicit memory) [10,11,12,13,14] and they appear during ontogeny and phylogeny at two different moments [1,2]. Clinical observations clearly demonstrate that there are two major aphasia syndromes (Wernicke-type and Broca-type aphasia) (for a review, see: [15]) due to damage in rather different brain areas (temporal and frontal) and associated with the impairment of each one of these language dimensions (lexical/ semantic and grammatical) (Figure 1).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
