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

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

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

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 furrow. However, the parietal lobe works in conjunction with that and the rest of the brain lobes , as it includes a large association area, which can be seen as a central area in which many types of information are mixed to generate a unit.

Although the parietal lobe specializes more 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. All the sensory information that comes to us from the outside world is integrated into the memories, but also the feelings and emotions linked to that piece of memory. In other words, the parietal lobe is where both perceptive processes and the regulation of moods flow.

Thus, if only one word is to be chosen to define the function of the parietal lobe, it 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 in the parietal lobe are many and varied , but in summary it can be said that they play an important role, especially in three types of processes: the integration and processing of sensory information from different “channels”, the processing of symbolic information (which includes processes related to language and its use) and the processing of numerical information, which is basic for counting and carrying out mathematical operations.

1. Sensory integration

The parietal lobe includes one of the major association areas of the brain , which means that information from all areas of the body are 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 associated movement, touch and smell.

But in the parietal lobe not only data about the world around us and what lives in it are given, but also information about how we relate to that world in real time . For example, it is in the parietal lobe that the data from the muscles of the body are joined, thanks to which we get an idea of the physical position and posture in which we find ourselves. The same is true for touch. Ultimately, the parietal lobe is responsible for somesthetic processing, that is, the sensory ability to recognize body sensations.

Similarly, the parietal lobe works alongside the frontal lobe to provide feedback on how the voluntary movements we are making are going, so that we can correct them immediately if unforeseen events are detected.

As a curiosity, this function includes graphesthesia, which is the ability to recognize letters and words when an element touches the skin making the route of the form of these.

2. Processing of symbolic-analytical information

Another great function 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 perceived sensorially that one can imagine a sequence of units with which to work 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.

Parietal lobe injuries

As is often the case in psychobiology, part of the functions of a brain structure tell us about the functions that they perform. In the case of the parietal lobe, these lesions speak about the multiplicity of tasks carried out by the groups of neurons in this part of the brain.

Injury to the left parietal lobe

An injury to the parietal lobe of the left hemisphere may result in the development of Gerstmann’s syndrome , which includes symptoms such as achalculia (acquired inability to perform calculations), confusion of the left and right and difficulty in writing (agraphia).

Injury to the right parietal lobe

With the rest of the brain in good health, a lesion in the right parietal lobe can produce hemineglectus , that is, the 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 hemineglect totally neglect one of the halves of their body, which means they don’t wash, dress, or comb it, and they will likewise act as if they are 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’s Syndrome may appear. This is a serious neurological disorder that mainly affects perception and psychomotor ability.

Among its symptoms is the inability to perceive the images as a whole, that is, you see separate elements but you do not know how far they are from each other or from the position they occupy. Similarly, they appear to be difficulties in coordinating eye movements (optical ataxia).

Concluding

The parietal lobe is characterized by the way it works together 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 area of the frontal lobe.

However, by its own distributed nature, the brain functions from networks of neurons spread over many different locations , 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 several 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 functional and possible. To do this, it processes some of the information that comes from other regions of the brain, and sends the information to other networks of nerve cells so that they can continue working on it.

Bibliographic references:

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