Language processing in the brain in the context of "Evolution of primates"

Language acquisition is the process by which humans acquire the capacity to perceive and comprehend language. In other words, it is how human beings gain the ability to be aware of language, to understand it, and to produce and use words and sentences to communicate.

Language acquisition involves structures, rules, and representation. The capacity to successfully use language requires human beings to acquire a range of tools, including phonology, morphology, syntax, semantics, and an extensive vocabulary. Language can be vocalized as in speech, or manual as in sign. Human language capacity is represented in the brain. Even though human language capacity is finite, one can say and understand an infinite number of sentences, which is based on a syntactic principle called recursion. Evidence suggests that every individual has three recursive mechanisms that allow sentences to go indeterminately. These three mechanisms are: relativization, complementation and coordination.

Broca's area, or the Broca area (/ˈbroʊkə/, also UK: /ˈbrɒkə/, US: /ˈbroʊkɑː/), is a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production.

Language processing has been linked to Broca's area since Pierre Paul Broca reported impairments in two patients. They had lost the ability to speak after injury to the posterior inferior frontal gyrus (pars triangularis) (BA45) of the brain. Since then, the approximate region he identified has become known as Broca's area, and the deficit in language production as Broca's aphasia, also called expressive aphasia. Broca's area is now typically defined in terms of the pars opercularis and pars triangularis of the inferior frontal gyrus, represented in Brodmann's cytoarchitectonic map as Brodmann area 44 and Brodmann area 45 of the dominant hemisphere.

Evolutionary linguistics or Darwinian linguistics is a sociobiological approach to the study of language. Evolutionary linguists consider linguistics as a subfield of sociobiology and evolutionary psychology. The approach is also closely linked with evolutionary anthropology, cognitive linguistics and biolinguistics. Studying languages as the products of nature, it is interested in the biological origin and development of language. Evolutionary linguistics is contrasted with humanistic approaches, especially structural linguistics.

A main challenge in this research is the lack of empirical data: there are no archaeological traces of early human language. Computational biological modelling and clinical research with artificial languages have been employed to fill in gaps of knowledge. Although biology is understood to shape the brain, which processes language, there is no clear link between biology and specific human language structures or linguistic universals.

The language module or language faculty is a hypothetical structure in the human brain which is thought to contain innate capacities for language, originally posited by Noam Chomsky. There is ongoing research into brain modularity in the fields of cognitive science and neuroscience, although the current idea is much weaker than what was proposed by Chomsky and Jerry Fodor in the 1980s. In today's terminology, 'modularity' refers to specialisation: language processing is specialised in the brain to the extent that it occurs partially in different areas than other types of information processing such as visual input. The current view is, then, that language is neither compartmentalised nor based on general principles of processing (as proposed by George Lakoff). It is modular to the extent that it constitutes a specific cognitive skill or area in cognition.

Dyslexia, also known as "word blindness", is a learning disability that affects either reading or writing. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, writing words, "sounding out" words in the head, pronouncing words when reading aloud and understanding what one reads. Often these difficulties are first noticed at school. The difficulties are involuntary, and people with this disorder have a normal desire to learn. People with dyslexia have higher rates of attention deficit hyperactivity disorder (ADHD), developmental language disorders, and difficulties with numbers.

Dyslexia is believed to be caused by the interaction of genetic and environmental factors. Some cases run in families. Dyslexia that develops due to a traumatic brain injury, stroke, or dementia is sometimes called "acquired dyslexia" or alexia. The underlying mechanisms of dyslexia result from differences within the brain's language processing. Dyslexia is diagnosed through a series of tests of memory, vision, spelling, and reading skills. Dyslexia is separate from reading difficulties caused by hearing or vision problems or by insufficient teaching or opportunity to learn.

Word-sense disambiguation is the process of identifying which sense of a word is meant in a sentence or other segment of context. In human language processing and cognition, it is usually subconscious.

Given that natural language requires reflection of neurological reality, as shaped by the abilities provided by the brain's neural networks, computer science has had a long-term challenge in developing the ability in computers to do natural language processing and machine learning.