Parietal lobe: characteristics and functions

The parietal lobe, located under the cranial bone that gives it its name and between the frontal and occipital lobes, is one of the most important brain structures both for their size and for the processes in which they participate.

In fact, it is so crucial to the success of various mental processes that it is virtually impossible to talk about it. part of the brain as if it were a "simple" piece of our nervous system or a structure that performs a single characteristic function.

Then we will see what are the characteristics of the parietal lobe and in what processes it participates.

• Related article: "Cerebral cortex: its layers, areas and functions"

What is the parietal lobe?

This part of the brain is an area of ​​the cerebral cortex that is located just behind the frontal lobe: both lobes are separated by the so-called central groove. However, the parietal lobe works together with that and the rest of the lobes of the brain, since it includes a large association area, which can be seen as a central in which many types of information are mixed to generate a unit.

Although the parietal lobe is more specialized in certain brain functions than others, one of its main characteristics is that integrates data from different sources. For example, it mixes data related to what is seen and those that tell us about what is heard, and makes a complete perceptual experience appear.

Similarly, in this area of ​​the cerebral cortex there are many memories that, once "stored" by the hippocampus, move until they are fixed in the neural networks of this lobe. In the memories are integrated all the sensory information that comes to us from the outside world, but also the feelings and emotions linked to that piece of memory. In other words, both perceptual processes and the regulation of moods flow into the parietal lobe.

Thus, if a single word is to be chosen to define what the function of the parietal lobe is, this should be "integration", a concept that refers to the functions of many other parts of the brain.

Functions of this area of ​​the brain

The functions carried out by the networks of neurons of the parietal lobe are many and varied., but in summary it can be said that it plays an important role especially in three classes of processes: integration and processing of sensory information coming from different "channels", the processing of symbolic information (which includes the processes related to language and its use) and the processing of numerical information, something basic to be able to count and perform operations math.

1. Sensory integration

One of the largest association areas of the brain is included in the parietal lobe, which means that information from all areas of the body is combined in this area to result in information that is more than the sum of its parts. Therefore, the creation of abstract concepts occurs in part thanks to the parietal lobe, thanks to which we are able to generate, for example, the idea of ​​what a dog is, with its movement, its touch and its smell associates.

But the parietal lobe not only brings together data about the world that surrounds us and what inhabits it, but also also information about how we relate to that world in real time. For example, it is in the parietal lobe where the data coming from the muscles of the body come together, thanks to which we get an idea about the physical position and posture in which we we find. The same goes for touch. Ultimately, the parietal lobe is responsible for somesthetic processing, that is, the sensory ability to recognize bodily sensations.

Similarly, the parietal lobe works together with the frontal lobe to offer a feedback about how the voluntary movements that we are doing are going, in order to be able to correct them immediately in the event that unforeseen events are detected.

As a curiosity, this function includes graphesia, which is the ability to recognize letters and words when an element touches the skin, traversing their shape.

2. Processing of symbolic-analytical information

Another of the great functions of the parietal lobe is to work with symbols and arithmetic. The mathematical function is carried out together with the previous one, since it is from the analysis of what is senses sensory perception of how you can imagine a sequence of units to work with mathematically.

As the parietal lobe is a place where many mental processes are mixed, it makes possible the abstract thinking necessary to think in symbols.

In this sense, the location of the parietal lobe is very relevant in this sense, since is in a central position where it can receive input from all parts of the central nervous system. This allows you to integrate information from very varied places, thus participating in the appearance of the global experience that appears in our consciousness.

Lesions in the parietal lobe

As happens many times in psychobiology, part of the functions of a brain structure tells us about the functions that these perform. In the case of the parietal lobe, these lesions speak about the multiplicity of tasks performed by groups of neurons of this part of the brain.

Lesion in the left parietal lobe

A wound in the parietal lobe of the left hemisphere can result in the appearance of Gerstmann Syndrome, which includes symptoms such as acalculia (acquired inability to perform calculations), confusion of the left and right and difficulty when writing (agrafia).

• Related article: "Alexia and agrafia: alterations in written language due to brain injury"

Injury to the right parietal lobe

The rest of the brain is in good health, an injury to the right parietal lobe can lead to hemine neglect, that is, inability to pay attention to the stimuli present on the left side of the body while the person is not aware of this problem (a phenomenon known as anosognosia).

People with hemine neglect totally neglect one half of their body, which means that they do not wash it, dress or comb it, and in the same way they will act as if they were ignoring everything that happens on one side of their Body.

Injury to both parietal lobes

When the parietal lobes of the left and right hemispheres are injured, Balint Syndrome can appear. This is a serious neurological disorder that mainly affects perception and psychomotor ability, and for which there is no cure, so the treatment is based on the management of the symptoms that produce.

Among its symptoms is the inability to perceive the images as a whole, that is, that they are seen separate elements but it is not known at what distance they are from oneself or from each other nor the position that occupy. Similarly, difficulties appear in the coordination of eye movements (optic ataxia).

Concluding

The parietal lobe is characterized by the way in which it works in conjunction with many other areas of the brain, offering them a space in which they can integrate their torrents of information with each other.

This, of course, does not mean that in this part of the cerebral cortex we cannot find more or less specialized areas, and in fact it has been seen that several of them are especially involved in vision and in the execution and monitoring of movements in coordination with the posterior lobe area frontal.

However, by its very distributed nature, the brain functions from networks of neurons scattered in many different places, and in this sense the parietal lobe is no exception. Consequently, these functions are very relative, and actually exist thanks to the joint work of various areas of the nervous system.

In conclusion, the parietal lobe works by coordinating with other areas of the cerebral cortex to make the processes of perception, thought and movement can occur and are functional. To do this, it processes part of the information that comes from other regions of the brain, and sends the information to other networks of nerve cells so that they continue to work on it.

Bibliographic references:

• Bradford, H.F. (1988). Neurochemistry Fundamentals. Work.
• Finlay, B.L.; Darlington, R.B.; Nicastro, N. (2001). Developmental structure in brain evolution. Behavioral and Brain Sciences. 24 (2): pp. 263 - 308.
• Culham JC, Valyear KF (2006). "Human parietal cortex in action". Curr Opin Neurobiol. 16 (2): 205–12.
• Goldenberg, G. (2009). Apraxia and the Parietal Lobes. Neuropsychology. 47 (6): pp. 1449 - 1459.
• Manes, F., Niro, M. (2014). Use the brain. Buenos Aires: Planet.
• Ratey, J. J. (2003). Brain: instruction manual. Barcelona: Mondadori.
• Zuluaga, J. TO. (2001). Neurodevelopment and stimulation. Madrid: Panamerican Medical.