The ability of the human being to read and write involves a large number of complex mental processes in which visual and auditory information come together, then motor in the case of writing. They involve complex processing and integration, which takes place in different regions of the brain.
One of the most important is Brodman area 40, or supramarginal gyrus. Let’s see how it is and what functions this part of the brain is responsible for.
Supramargineal rotation: this is the part of the parietal lobe
The supramarginal gyrus is one of the twists or convolutions of the brainThat is, one of the visible folds of the cerebral cortex. It is located in the lower parietal lobe, just above the Silvio cleft and closely related to the angular gyrus and Wernicke region. This convolution is present bilaterally (i.e. there is one in each cerebral hemisphere) and is of great importance in allowing certain complex processes to take place.
The parietal lobe is linked to a large number of basic functions of our daily life, such as oral and written language or auditory perception and participates in aspects such as orientation and memory. The functions performed by the parietal lobe cortex are mainly related to sensory perception and the processing and integration of information obtained by the senses.
The latter is one of the functions of the turn in question. Angular gyration is considered as an association domain, Which integrates information from other regions of the brain.
Supramarginial rotation functions
The supramarginal gyrus is an area of the brain of great importance, which, although mainly known for its role in language, has several functions.
One of the most well-known functions of supramarginial rotation is to enable, alongside angular rotation, literacy. To be able to read and write, we must be able to integrate visual and sound material so as to be able to associate phonemes and graphemes, that is to say the sounds and the letters which represent them. They are both turns, angular and supramarginal, which also make it possible to associate visual representation and meaning.
This function is what makes the supramarginial rotation next to the Broca and Wernicke zones and the angular rotation. one of the main brain structures of language.
2. Working memory
It has been shown that apart from its role in language, supramarginal rotation has connections with the dorsolateral prefrontal cortex that make it a relevant area for updating working memory.
It has also been observed that supramarginal rotation participates in the acquisition of skills, especially those involving movement. Although this is not something confirmed, it is suspected that he is capable of record information about the position of members based on memory of previous events.
4. Tactile perception
The supramarginal turn has been linked not only to linguistic and cognitive aspects but also to the perception of tactile stimuli, in particular to their recognition.
Disorders and situations in which it is impaired
The alteration or lesion of this brain region can have different repercussions of varying severity, being visible alterations in supramarginial rotation in patients with different disorders.
It is common to find involvement or alterations in this area in patients with aphasia. It is understood as such that disorder in which understanding and / or speaking the language is made difficult or impossible, Caused by brain injury.
The type of aphasia in which it is more common than damage in the supramarginal turn is that of conduction, in which the repetition of words is damaged although the understanding and expression of the language remains unchanged.
Because the supramarginial rotation and is one of the main areas with the angular integration between visual and auditory material, their lesion or dysfunction and are related to alexia, which imply the existence of severe difficulties the time to be able to interpret or read a text.
Thus, an injury in the supramarginal gyrus will be presumptive impaired reading ability by not being able to correctly associate the visual representation with its meaning.
3. Bodily neglect
That said, supramarginial rotation is not only involved in language, but also performs other functions. Alterations in supramargineal rotation can also lead to the presence of spatial neglect in the body itself. There may also be problems with working memory.
Apart from this, alterations in the supramarginal gyrus also appear in some mental disorders. For example, we observe that there is a relationship between this area and auditory hallucinations in schizophreniaThere is a correlation between the size of the supramarginial rotation and their severity.
- Clark, DL; Boutros, NN and Méndez, MF (2012). The brain and behavior: neuroanatomy by psychologists. 2nd edition. The modern manual. Mexico.