From the Research
The Heschl's gyrus is a critical region in the brain for processing auditory information, and its functional organization and role in speech perception have been elucidated by recent studies, such as the one published in 2021 1. The Heschl's gyrus, also known as the transverse temporal gyrus, is a region of the brain located in the temporal lobe that serves as the primary auditory cortex. This structure is responsible for processing incoming auditory information from the ears, allowing us to perceive and interpret sounds. Some key points about the Heschl's gyrus include:
- It is typically larger in the left hemisphere in most people, which may relate to language processing, as the left hemisphere is generally dominant for language functions 2.
- The Heschl's gyrus receives direct input from the medial geniculate nucleus of the thalamus and organizes sound information tonotopically, meaning different frequencies of sound are processed in different areas of the gyrus.
- Damage to this area can result in various auditory processing disorders, including difficulty distinguishing between different sounds or comprehending speech.
- Recent studies have shown that the Heschl's gyrus is pre-activated to facilitate the perception of forthcoming sound events, and is associated with increased gamma oscillations and desynchronized low frequency activity 3.
- Morphometric differences in the Heschl's gyrus have been observed between hearing impaired and normal hearing infants, with the hearing impaired group showing increased gray matter and decreased white matter in the anterior portion of the gyrus 4.
- The Heschl's gyrus is more sensitive to tone level than non-primary auditory cortex, and the extent and magnitude of auditory activation increase non-linearly with sound level 5. Overall, the Heschl's gyrus plays a crucial role in auditory processing, and its functional organization and morphometric characteristics are essential for understanding speech perception and auditory disorders, as demonstrated by the most recent and highest quality study published in 2021 1.