People are used to living with sound. Feeling everything around us is something we’ve internalized so much that we don’t even stop to think about how this information enters our ears and is experienced by us.
In this article we will talk about the auditory areas of the brain, Which, along with the auditory system, is responsible for collecting these signals sent by the auditory nerves and sending the information already processed to the rest of the nervous system.
What are the auditory zones of the brain?
The auditory areas of our brain include both the auditory pathways, which consist of bundles of fibers that carry information from the ear to the brain and back again, as well as areas of the brain dedicated to hearing.
These cerebral zones are the trunk of the brain with the complex of olive superior, lemnisco and colículo; the thalamus and the primary auditory cortex.
In addition, the importance of auditory nerve function should be noted. This nerve is essential for our hearing. Composed of more than 30,000 neurons, it is responsible, along with the auditory pathways, for transporting information to the brain by electrical impulses.
Function of auditory pathways
Like other sensory modalities, the auditory system is made up of a number of primary pathways and brain centers the function is to process and transport auditory information.
In the case of auditory pathways, we find the primary auditory pathway, the sole purpose of which is to transport auditory information, and the non-primary pathway which also integrates other sensory modalities.
Primary ear canal
The main auditory pathway is a short neural circuit and with the ability to carry information very quickly because it is made up of thick myelin fibers.
Its only task is to transport the information collected by the cochlea, performing decoding and interpretation tasks at each level. This information is transferred from one level to another until it reaches the auditory cortex.
However, before the information reaches the auditory cortex, the thalamus integrates the information and prepares to emit a response or reaction to an auditory stimulus.
After the first level, which integrates the two auditory pathways into one, part of this pathway known as the non-primary pathway departs to join the ascending reticular pathway, which integrates sensory information of all kinds.
The main function of this route is to bring together several different sensory messages, but which are given at the same time, to select those which need to be dealt with more urgently.
Parts of the brainstem involved in hearing
The brainstem is the structure through which almost all sensory pathways pass, and its function is to communicate between the spinal cord, cerebellum, and brain. In him we can locate the nuclei corresponding to the auditory system in the brain. These are the following.
1. Cochlear nuclei
Cochlear nuclei are located on the surface of the brainstem, Being its main function that of examining the intensity of the sound, as well as the beginning, the duration and the end of it. In addition, they also provide information to the brain about the frequency of the sound, i.e. whether it is low pitched or high pitched sounds.
2. Superior olive complex
One of the most complex systems in the auditory brain is the upper olive complex. Its dense neural network is designed to analyze and filter all acoustic information that goes to the cerebral cortex.
3.lateral lesion and colic
The nucleus of the lateral limnic is involved in the encoding of the duration of the most complex sounds.
On another side, the colículo is divided into dorsal and outer crust and the central nucleus, Which is made up of a large number of neurons.
The dorsal and outer cortex are engaged in the examination of acoustic information and in the recognition of complex sounds. While the central core analyzes the frequency of sound and divides it into bass or treble.
The thalamus and the auditory cortex
Other areas of the brain involved in hearing are the thalamus and the auditory cortex. Let’s see how they work.
The auditory thalamus, also known as the medial geniculate body (CGM), Receives fibers as much from the dorsal and outer crust of the colic as from the central core thereof. This part of the thalamus is divided into three areas specialized in a function. These areas are: the dorsal area, the middle area and the ventral area.
Neurons in the dorsal region send projections to the secondary auditory cortex. These neurons must respond to several different sensory stimuli.
Their neurons travel to the primary auditory cortex and they also participate in the analysis of the sound frequency, Maintain latency between communications.
Primary auditory cortex
At people’s Place, the auditory cortex covers 8% of the entire surface of the cerebral cortex.
This primary auditory cortex is made up of more than twelve different auditory fields they are located in the upper area of the temporal lobe, Where they extend by the angular bend towards the Silvio slot; there are the transverse turns of Heschl.
This area of the brain can in turn be divided into two regions differentiated by the organization of their neurons and their functions. These areas are as follows.
- The AI zone is made up of neurons that determine the spatial representation of the stimulus.
- The AII zone is dedicated to locate sound in space, to examine complex sounds and is closely related to auditory memory.
Finally, the area around these two areas is responsible for analyzing and integrating auditory information with the rest of the sensory information that the person perceives.