Finally, the messages continue to the thalamus and end up in the sensory areas located in the cerebral cortex, the outer layer of our cerebrum. In the reticular formation, the information that should be treated as a priority is selected in accordance with the wake and motivation centers and further treated. Hereafter, the auditory information passes through the reticular formation, a region in the brain stem consisting of more than a hundred small neural networks. The processing of sensory data within the non-primary auditory pathways also starts in the brain stem. For example, when reading a newspaper while listening to the radio, this system permits the person to focus on the most vital task. The core function of these pathways is hence to choose the type of sensory message to be treated first. In contrast to the primary auditory pathway, non-primary auditory pathways process all sorts of sensory messages. However, in the auditory cortex the signal is moreover recognised, memorised and may eventually result in a response. It lies in the posterior half of the superior temporal gyrus and also dives into the lateral sulcus as the transverse temporal gyri also called Heschl’s gyri. The primary auditory cortex is about the same as Brodmann areas 41 and 42. At this stage the message has already been largely decoded. The auditory cortex is located on the lateral surface in the temporal lobe of the brain. The last neuron of the primary auditory pathway connects the thalamus with the auditory cortex. The thalamus integrates the sensory systems in the body and hence functions as an essential factor in the preparation of a motor response e.g. ![]() The next stop occurs in the thalamus, an ovoid mass of grey substance situated at the base of the cerebrum. Subsequently, the message passes two additional relays that play an important role in the localisation of the sound. This pathway carries messages from the cochlea to a sensory area of the temporal lobe called the auditory cortex.įirst stop on this journey is taken in the brain stem, where a decoding of basic signals such as duration, intensity and frequency takes place. The processing of decoded sound material starts within the primary auditory pathway. This assessment is followed-up by an appropriate voluntary response. Other brain areas can allow the perception to become conscious as well and hence recognise the sound by relating it to those that have been memorised in the past. ![]() Thereafter, the processing might also unfold in the auditory cortex, where the sound is consciously perceived. Thus, the arrival of the message may first of all trigger a reflex and cause us to jump or turn our head. Transformation and processing of sound generally occurs on three levels in the brain: As a reflex, in the auditory cortex and in other brain areas. This translation occurs in order to cause a conscious perception of the sounds that we receive. In the auditory brain, several groups of neurons receive the impulses and translate them into a language that our brain understands. Once the hair fibres of the cochlea, the snail shell-resembling organ of the inner ear, have sent electrical signals to the auditory nerve, these impulses are transferred to the auditory centre of the brain.
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