<P> There is also reason to believe that children use various heuristics to properly infer the meaning of words . Markman and others have proposed that children assume words to refer to objects with similar properties ("cow" and "pig" might both be "animals") rather than to objects that are thematically related ("cow" and "milk" are probably not both "animals"). Children also seem to adhere to the "whole object assumption" and think that a novel label refers to an entire entity rather than one of its parts . This assumption along with other resources, such as grammar and morphological cues or lexical constraints, may help aid the child in acquiring word - meaning, but they also conflict some of the time . </P> <P> According to several linguists, neurocognitive research has confirmed many standards of language learning, such as: "learning engages the entire person (cognitive, affective, and psychomotor domains), the human brain seeks patterns in its searching for meaning, emotions affect all aspects of learning, retention and recall, past experience always affects new learning, the brain's working memory has a limited capacity, lecture usually results in the lowest degree of retention, rehearsal is essential for retention, practice (alone) does not make perfect, and each brain is unique" (Sousa, 2006, p. 274). In terms of genetics, the gene ROBO1 has been associated with phonological buffer integrity or length . </P> <P> Although it is difficult to determine without invasive measures which exact parts of the brain become most active and important for language acquisition, fMRI and PET technology has allowed for some conclusions to be made about where language may be centered . Kuniyoshi Sakai proposed, based on several neuroimaging studies, that there may be a "grammar center", where language is primarily processed in the left lateral premotor cortex (located near the pre central sulcus and the inferior frontal sulcus). Additionally, these studies proposed that first language and second - language acquisition may be represented differently in the cortex . In a study conducted by Newman et al., the relationship between cognitive neuroscience and language acquisition was compared through a standardized test procedure involving native speakers of English and native Spanish speakers who have all had a similar amount of exposure to the English language (averaging about 26 years). Even the number of times an examinee blinked was taken into account during the examination process . It was concluded that the brain does in fact process languages differently, but instead of it being directly related to proficiency levels, it is more so about how the brain processes language itself . </P> <P> During early infancy, language processing seems to occur over many areas in the brain . However, over time, it gradually becomes concentrated into two areas--Broca's area and Wernicke's area . Broca's area is in the left frontal cortex and is primarily involved in the production of the patterns in vocal and sign language . Wernicke's area is in the left temporal cortex and is primarily involved in language comprehension . The specialization of these language centers is so extensive that damage to them results in a critical condition known as aphasia . </P>

Describe the various stages of the first language acquisition