Heschyl's+Gyrus

Also known as the transverse temporal gyrus, it is the the primary auditory receiving area and association cortices.

Function
Here auditory signals undergo extensive analysis and reanalysis and simple associations are established. Prior to reaching the neocortex auditory signals have already undergone extensive analysis by the medial thalamus, amygdala, and other ancient structures. Heschl's gyri is especially well developed in humans. In fact, some individuals appear to possess multiple Heschl gyri--though the significance of this is not clear. However, it has been reported that this may be a reflection of genetic disorders, learning disabilities, and so on.

**Broadman's Areas **
Posterior Gyri 41 - primary auditory receiving area 42 - association cortices

The primary auditory neocortex is located on the two transverse gyri of Heschl, along the dorsal-medial surface of the superior temporal lobe. The center most portion of the anterior transverse gyri contains theprimary auditory receiving area - Broadman's area 41 and neocortically resembles the primary visual (area 17) and somesthetic cortices (area 3).

The major source of auditory input is derived from the medial geniculate thalamic nucleus as well as the pulvinar (which also provides visual input).

**Laterality **
primary auditory region receives some input from both ears, and from both halves of auditory space. This is a consequence of the considerable interconnections and cross-talk which occurs between different subcortical nuclei as information is relayed to and from various regions prior to transfer to the neocortex. Predominantly, however, the right ear transmits to the left cerebral neocortex and vice versa.

**AUDITORY RECEIVING AREA NEUROANATOMICAL-FUNCTIONAL ORGANIZATION. **
tonotopically organized - different auditory frequencies are progressively anatomically represented. <span style="color: #000000; font-family: 'Times New Roman',serif;">There is evidence to suggest that the auditory cortex is also "cochleotopically" organized - high frequencies are received and analyzed in the anterior-medial portions and low frequencies in the posterior-lateral regions of the superior temporal lobe <span style="color: #000000; font-family: 'Times New Roman',serif;">Also processes and perceives pitch and intensity, as well as modulations in frequency. <span style="color: #000000; font-family: 'Times New Roman',serif;">Primary auditory neurons are especially responsive to the temporal sequencing of acoustic stimuli.

<span style="color: #000000; font-family: 'Times New Roman',serif;">Moreover, the auditory cortex appears to be organized so as to detect tones in noise, i.e. the non-random structure of natural sounds, which enables it to selectively attend to environmental and animal sounds including human vocalizations.

<span style="color: #000000; font-family: 'Times New Roman',serif;">Some neurons will react to the patient's voice, whereas yet others will selectively respond to a particular (familiar) voice or call, but not to others--which in regard to voices, indicates that these cells (or neural assemblies) have engaged in learning. <span style="color: #000000; font-family: 'Times New Roman',serif;">Auditory neurons in fact, display neurplasticity in response to learning as well as injury. For example, auditory neurons can be classically conditioned so as to form associations between stimuli (e.g.paired with a noxious stimulus)

<span style="color: #000000; font-family: 'Times New Roman',serif;">Also display neuroplasticity in response to injury and loss of hearing. <span style="color: #000000; font-family: 'Times New Roman',serif;">Ex: cochlear or peripheral hearing loss, neurons that no longer receive high frequency auditory input, begin to respond instead to middle frequencies or in response to complete loss of hearing, such as congenital deafness, these neurons may cease to respond to auditory input and may instead respond to body language, such as the signing used by the deaf.