Middle temporal gyrus

At a glance

English

Middle temporal gyrus

Latin (TA2)

Gyrus temporalis medius

System

Brain and spinal cord

Region

Head

Side

Paired, left and right

About the middle temporal gyrus

The middle temporal gyrus runs from near the temporal pole back towards the occipital lobe along the side of the temporal lobe. It lies between the superior temporal sulcus above, which separates it from the superior temporal gyrus, and the inferior temporal sulcus below, which separates it from the inferior temporal gyrus. Its back end has no clear natural border; by convention it is closed off by an imaginary line running from the preoccipital notch on the lower margin of the hemisphere up to the end of the lateral sulcus. Most of its cortex is Brodmann area 21, with area 37 at its back end.

It is a long, often broad gyrus, and its posterior part bends upwards around the end of the superior temporal sulcus to meet the angular gyrus of the parietal lobe. It is joined to the frontal lobe and other temporal areas by association bundles, including the arcuate fasciculus, the inferior longitudinal fasciculus and the middle longitudinal fasciculus.

Functions of the gyrus are many and not neatly separated. It is part of the network for understanding language, especially for linking words with their meanings, and the left posterior middle temporal gyrus is regularly active when reading and retrieving words. The cortex along the superior temporal sulcus nearby responds to faces, voices and gestures, and the gyrus has been linked with recognising familiar faces, combining what is seen and heard in emotional expressions, and judging distance. It is also active during creative language tasks such as composing poetry. Its posterior end merges with the motion-sensitive visual area at the temporo-occipital junction.

Damage to the left posterior middle temporal gyrus, often from a stroke in the inferior division of the middle cerebral artery, can impair comprehension and naming. In Japanese readers, lesions here have been reported to affect reading and writing of kanji characters more than syllabic script. The gyrus also lies over the temporal horn of the lateral ventricle and is a common route of access in surgery on the medial temporal lobe.

Function and supply

Function

Involved in language comprehension and word meaning, reading, face and voice recognition and the combination of sight and sound in emotional cues.

Blood supply

Temporal branches of the inferior division of the middle cerebral artery.