Brodmann area 22 is a

Brodmann's area A Brodmann area is a region of the cerebral cortex, in the human or other primate brain, defined by its cytoarchitecture, or histological structure and organization of cells. History Brodmann areas were originally defined and numbered by the G ...

that is

cytoarchitecturally Cytoarchitecture (Ancient Greek language, Greek ''wiktionary:κύτος#Ancient_Greek, κύτος''= "cell" + ''wiktionary:ἀρχιτέκτων#Ancient_Greek, ἀρχιτεκτονική''= "architecture"), also known as cytoarchitectonics, is th ...

located in the posterior

superior temporal gyrus The superior temporal gyrus (STG) is one of three (sometimes two) gyri in the temporal lobe of the human brain, which is located laterally to the head, situated somewhat above the external ear. The superior temporal gyrus is bounded by: * the lat ...

of the brain. In the left cerebral hemisphere, it is one portion of Wernicke's area. The left hemisphere BA22 helps with generation and understanding of individual words. On the right side of the brain, BA22 helps to discriminate pitch and sound

intensity Intensity may refer to: In colloquial use *Strength (disambiguation) *Amplitude * Level (disambiguation) * Magnitude (disambiguation) In physical sciences Physics *Intensity (physics), power per unit area (W/m2) *Field strength of electric, ma ...

, both of which are necessary to perceive

melody A melody (from Greek language, Greek μελῳδία, ''melōidía'', "singing, chanting"), also tune, voice or line, is a Linearity#Music, linear succession of musical tones that the listener perceives as a single entity. In its most liter ...

and prosody. Wernicke's area is active in processing language and consists of the left Brodmann area 22 and Brodmann area 40, the supramarginal gyrus. It is bounded rostrally by

Brodmann area 38 Brodmann area 38, also BA38 or temporopolar area 38 (H), is part of the temporal cortex in the human brain. BA 38 is at the anterior end of the temporal lobe, known as the temporal pole. BA38 is a subdivision of the cytoarchitecturally defined ...

, medially by

Brodmann area 42 42 may refer to: * 42 (number) * The years 42 BC and AD 42 Arts, entertainment, and media * 42 (dominoes), a game * ''42'' (film), a 2013 biopic about American baseball player Jackie Robinson * ''42'', a 2021 album by Sech * 42, the Answer to t ...

, ventrocaudally by

Brodmann area 21 Brodmann area 21, or BA21, is part of the temporal cortex in the human brain. The region encompasses most of the lateral temporal cortex and is also known as middle temporal area 21. In the human it corresponds approximately to the middle tempor ...

, and dorsocaudally by Brodmann area 40, and Brodmann area 39. These cortical regions surround the lower left posterior Sylvian fissure.

Language

The Brodmann areas that are relevant to language include Broca's area (BA 44/45) and Wernicke's area (BA 42/22), where Broca's area is responsible for language production and Wernicke's area is responsible for language comprehension.

Function

Brodmann area 22 (BA 22) combined with Brodmann area 42 (BA 42) form Wernicke’s area in the

in the temporal lobe. Using cytoarchitectonics, BA 22 is located in the superior temporal gyrus which separates it from the primary and secondary auditory cortex. BA 22 is connected with nonverbal sound processing in the right hemisphere of the brain associated with activation in the auditory cortex. More functions associated with language in Brodmann area 22 include producing sentences, semantic processing, and processing of complex sounds. This area of the human brain supports

lexical semantic Lexical may refer to: Linguistics * Lexical corpus or lexis, a complete set of all words in a language * Lexical item, a basic unit of lexicographical classification * Lexicon, the vocabulary of a person, language, or branch of knowledge * Lexical ...

processing and is responsible for language comprehension and production. Wernicke's area is shown to support lexical-semantics because lesions to this area result in difficulties displaying word selection during production of language.

Wernicke's Aphasia

Because Wernicke’s area supports language comprehension in the temporal lobe, lesions to the left auditory cortex, specifically in BA 22, results in Wernicke’s aphasia. Wernicke’s aphasia, also known as receptive aphasia, is a language disorder characterized as having difficulty comprehending language. This disorder varies in outcomes based on severity and localization of the brain damage, which is mostly commonly due to having a stroke. Patients diagnosed with Wernicke's aphasia are shown to have normal intonation and rate of speech, however have difficulty understanding different words of a language. Many individuals have poor awareness when making errors in speech, but are typically able to produce normal sentence structures when speaking. These sentences produced by patients with Wernicke's aphasia are often difficult for others to understand because of the problems with word selection and comprehension. These difficulties are shown at a lexical level, for example patients often struggle with naming figures due to accessing words from the

lexicon A lexicon is the vocabulary of a language or branch of knowledge (such as nautical or medical). In linguistics, a lexicon is a language's inventory of lexemes. The word ''lexicon'' derives from Koine Greek language, Greek word (), neuter of () ...

Methodology

Methods used to understand functional activity in BA 22 consists mainly of

Functional magnetic resonance imaging Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area o ...

. Functional magnetic resonance imaging (fMRI) is a neuroimaging technique used to understand how language is processed in the BA 22.

Magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...

(MRI) is a technique used to study volume of grey matter and white matter in Brodmann area 22 to find deficits in the structural volume.

Parcellations

Brodmann areas are based on cytoarchitectonic parcellation using numbering associated with locations in the brain to illustrate functional activity. BA 22 is separated from the primary and secondary auditory cortex by using cytoarchitectonic parcellation. Connectivity-based parcellations in BA 22 can be broken into three subparts: posterior, middle, and anterior subparts of the superior temporal gyrus. Using connectivity-based parcellations involves connections between white fibers to different areas in the brain. Cytoarchitectonic parecellations and connectivity-based parcellations are two ways of breaking the brain down to the structure and the connection fibers of Brodmann Area 22.

References

Gallery

File:Brodmann area 22 inside lateral sulcus.png, Inside and outside of lateral sulcus. BA22 is shown in orange.

External links

* For Neuroanatomy of the superior temporal area 22 visi
BrainInfo
* For Neuroanatomy of Brodmann area 22 visi
BrainInfo
{{Prosencephalon 22 Temporal lobe