The superior temporal gyrus (STG) is one of three (sometimes two)

gyri In neuroanatomy, a gyrus (pl. gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; sg. ''sulcus''). Gyri and sulci create the folded appearance of the brain in humans and other ma ...

in the

temporal lobe The temporal lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe ...

of the human

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

, which is located laterally to the head, situated somewhat above the external ear. The superior temporal gyrus is bounded by: * the

lateral sulcus In neuroanatomy, the lateral sulcus (also called Sylvian fissure, after Franciscus Sylvius, or lateral fissure) is one of the most prominent features of the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the ...

above; * the

superior temporal sulcus The superior temporal sulcus (STS) is the sulcus separating the superior temporal gyrus from the middle temporal gyrus in the temporal lobe of the brain. A sulcus (plural sulci) is a deep groove that curves into the largest part of the brain, ...

(not always present or visible) below; * an imaginary line drawn from the preoccipital notch to the

posteriorly Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

. The superior temporal gyrus contains several important structures of the

, including: *

Brodmann areas 41 and 42 Brodmann areas 41 and 42 are parts of the primary auditory cortex. Brodmann area 41 is also known as the anterior transverse temporal area 41 (H). It is a cytoarchitectonic division of the cerebral cortex occupying the anterior transverse tem ...

, marking the location of the

auditory cortex The auditory cortex is the part of the temporal lobe that processes auditory information in humans and many other vertebrates. It is a part of the auditory system, performing basic and higher functions in hearing, such as possible relations to ...

, the cortical region responsible for the sensation of

sound In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the ...

; *

Wernicke's area Wernicke's area (; ), also called Wernicke's speech area, is one of the two parts of the cerebral cortex that are linked to speech, the other being Broca's area. It is involved in the comprehension of written and spoken language, in contrast to B ...

, Brodmann 22p, an important region for the processing of

speech Speech is a human vocal communication using language. Each language uses Phonetics, phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if ...

so that it can be understood as language. The superior temporal gyrus contains the auditory cortex, which is responsible for processing sounds. Specific sound frequencies map precisely onto the auditory cortex. This auditory (or tonotopic) map is similar to the

homunculus A homunculus ( , , ; "little person") is a representation of a small human being, originally depicted as small statues made out of clay. Popularized in sixteenth-century alchemy and nineteenth-century fiction, it has historically referred to the ...

map of the

primary motor cortex The primary motor cortex (Brodmann area 4) is a brain region that in humans is located in the dorsal portion of the frontal lobe. It is the primary region of the motor system and works in association with other motor areas including premotor co ...

. Some areas of the superior temporal gyrus are specialized for processing combinations of frequencies, and other areas are specialized for processing changes in amplitude or frequency. The superior temporal gyrus also includes Wernicke's area, which (in most people) is located in the left hemisphere. It is the major area involved in the comprehension of language. The superior temporal gyrus is involved in auditory processing, including language, but also has been implicated as a critical structure in social cognition.Erin D. Bigler, Sherstin Mortensen, E. Shannon Neeley, Sally Ozonoff, Lori Krasny, Michael Johnson, Jeffrey Lu, Sherri L. Provencal, William McMahon & Janet E. Lainhart (2007): Superior Temporal Gyrus, Language Function, and Autism, Developmental Neuropsychology, 31:2, 217-238 Various parts of the STG might be referred to as anterior (aSTG), middle (mSTG), and posterior (pSTG).

Function

The superior temporal gyrus has been involved in the perception of emotions in facial stimuli. ) Furthermore, the superior temporal gyrus is an essential structure involved in auditory processing, as well as in the function of language in individuals who may have an impaired vocabulary, or are developing a sense of language. The superior temporal gyrus has been discovered to be an important structure in the pathway consisting of the amygdala and prefrontal cortex, which are all involved in social cognition processes. Including the superior temporal gyrus, areas more anterior and dorsal within the temporal lobe have been linked to the ability of processing information the many changeable characteristics of a face. Research conducted with the use of neuroimaging have found patients with schizophrenia have structural abnormalities in their superior temporal gyrus. fMRI analysis has evidenced a link between

insight Insight is the understanding of a specific cause and effect within a particular context. The term insight can have several related meanings: *a piece of information *the act or result of understanding the inner nature of things or of seeing intu ...

based problem solving and activity in the right anterior superior-temporal gyrus, specifically in relation to the sudden flash of understanding commonly referred to as an 'Aha!' moment.

Social context

The superior temporal gyrus (STG) is important for language comprehension, but studies also suggest that it plays a functional role in the

cocktail party effect The cocktail party effect is the phenomenon of the brain's ability to focus one's auditory attention on a particular stimulus while filtering out a range of other stimuli, such as when a partygoer can focus on a single conversation in a noisy room ...

. A

magnetoencephalography Magnetoencephalography (MEG) is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers. Arrays of SQUIDs (su ...

study was conducted on participants that were exposed to five differing listening conditions each with a different level of background noise. It was discovered that the STG has a strong connection with the attended speech stream in a cocktail party setting. When the attended speech stream wasn’t disrupted by background noise a bilateral connection was displayed, but as more background noise was introduced the connection became left-hemisphere-dependent.

Additional images

File:Superior temporal gyrus animation small.gif, Position of superior temporal gyrus (shown in red). File:Gehirn, lateral - Hauptgyri beschriftet.svg, Lateral view of a human brain, main gyri labeled. File:Gray1197.png, Drawing of a cast to illustrate the relations of the brain to the skull. (Superior temporal gyrus labeled at center, in green section.) TempCaptsLateral.png, Right

(shown in green). Superior temporal gyrus is visible at the top of the green area. File:Superior_Temporal_-_DK_ATLAS.png, Superior temporal gyrus, right hemisphere. File:Superior temporal gyrus coronal sections.gif, Superior temporal gyrus highlighted in green on coronal T1 MRI images File:Superior temporal gyrus sagittal sections.gif, Superior temporal gyrus highlighted in green on sagittal T1 MRI images File:Superior temporal gyrus transversal sections.gif, Superior temporal gyrus highlighted in green on transversal T1 MRI images

References

Erin D. Bigler, Sherstin Mortensen, E. Shannon Neeley, Sally Ozonoff, Lori Krasny, Michael Johnson, Jeffrey Lu, Sherri L. Provençal, William McMahon & Janet E. Lainhart (2007): Superior Temporal Gyrus, Language Function, and Autism, Developmental Neuropsychology, 31:2, 217-238

External links

* {{Authority control Gyri Temporal lobe