Key Concepts in Neurolinguistics and Language Acquisition

bottom-up processing

Data-driven analysis of linguistic input that begins with the small units like phones and proceeds stepwise to increasingly larger units like words and phrases until the entire input is processed, often ending in a complete sentence and semantic interpretation.

semantic priming

The effect of being able to recognize a word (for example, doctor) more rapidly after exposure to a semantically similar word (for example, nurse) than after exposure to a semantically more distant word. The word nurse primes the word doctor.

garden path sentences

Sentences that appear at first blush to be ungrammatical, but with further syntactic processing turn out to be grammatical: for example, The horse raced past the barn fell.

Neurolinguistics

The branch of linguistics concerned with the brain mechanisms that underlie the acquisition and use of human language; the study of the neurobiology of language.

Cortex

The approximately ten billion neurons that form the outside surface of the brain; also referred to as gray matter.

cerebral hemisphere

The left and right halves of the brain, joined by the corpus callosum.

Localization

The hypothesis that different areas of the brain are responsible for distinct cognitive functions.

Acquired aphasia

Language loss or disorder following brain damage.

Broca's area

A front part of the left hemisphere of the brain, damage to which causes agrammatism or Broca's aphasia.

Wernicke's area

The back (posterior) part of the left brain that if damaged causes a specific type of aphasia.

Lateralization

Terms used to refer to cognitive functions localized to one or the other hemisphere of the brain.

Broca's aphasia

Language disorder usually resulting from damage to Broca's region in which the patient has difficulty with certain aspects of syntax, especially functional categories.

Wernicke's aphasia

The type of aphasia resulting from damage to Wernicke's area.

anomia (anomic aphasia)

A form of aphasia in which patients have word-finding difficulties.

acquired dyslexia

Loss of ability to read correctly following brain damage in persons who were previously literate.

magnetic resonance imaging (MRI)

A technique to investigate the molecular structures in human organs including the brain, which may be used to identify sites of brain lesions.

functional MRI (fMRI)

Functional Magnetic Resonance Imaging: scans that can reveal the brain in action by measuring blood flow and oxygen utilization in different locations in the brain during the performance of various linguistic and other cognitive tasks.

split-brain

The result of an operation for epilepsy in which the corpus callosum is severed; thus, separating the brain into its two hemispheres; split-brain patients have been studied to determine the role of each hemisphere in cognitive and language processing.

critical-age hypothesis

The theory that there is a window of time between early childhood and puberty for learning a first language, and beyond which first language acquisition is almost always incomplete.

Specific Language Impairment (SLI)

Difficulty in acquiring language by certain children with no other cognitive deficits.

Psycholinguistics

The branch of linguistics concerned with linguistic performance, and speech production and comprehension.

second language acquisition

The acquisition of another language or languages after first language acquisition is under way or completed. Also called L2 acquisition.

L2 acquisition

See second language acquisition.

sequential bilingualism

The acquisition of a second language by someone (adult or child) who has already acquired a first language. More commonly referred to as child or adult second language (L2) acquisition.

Bilingual language acquisition

The (more or less) simultaneous acquisition of two or more languages before the age of three years such that each language is acquired with native competency.

simultaneous bilingualism

Refers to the (more or less) simultaneous acquisition of two languages beginning in infancy (or before the age of three years).

Codeswitching

A bilingual person's movement back and forth between two languages or dialects within the same sentence or discourse.

fundamental difference hypothesis

The idea that adult second language acquisition (L2) differs fundamentally from first language acquisition (L1).

interlanguage grammars

The intermediate grammars that second-language learners create on their way to acquiring the (more or less) complete grammar of the target language.

Transfer

The application of rules from one's first language to a second language that one is attempting to acquire. The 'accent' that second-language learners have is a result of the transfer of first language phonetic and phonological rules.

heritage language

A language with which a person has a strong cultural connection through family interaction, but that isn't learned natively: for example, Yiddish in a Jewish household.

language attrition

The gradual loss of heritage language competence owing to lack of use. See heritage language.