BRODMANN AREAS: HISTORY, CHARACTERISTICS AND FUNCTIONS - NEUROPSYCHOLOGY - 2024

The Brodmann areas are regions of the cerebral cortex that can be found both in humans and primates. They were first described in 1909 by the German doctor Korbinian Brodmann, who defined them based on the cytoarchitectural organization of neurons that he observed using the Nissl staining method.

It is generally considered that there are 47 different Brodmann areas, although some authors separate several of them into two parts, resulting in a total of 52. The exact functions of each of the areas and the division of these have been the object of many debates within the field of neuroanatomy since they were proposed.

Brodmann areas. By: Henry Vandyke Carter

In fact, today Brodmann's classification is the most widely used when it comes to the cytoarchitectural organization of the human cerebral cortex. In fact, in recent years, many of the areas that had only been defined on the basis of their neural organization have been studied in greater depth, and it has been discovered that they play a fundamental role in various cortical functions.

Not all Brodmann areas are as well known or have been the subject of the same amount of study. For example, it is known that areas 1, 2 and 3 form the majority of the primary somatosensory cortex, area 17 is the primary visual cortex, and areas 44 and 45 correspond in most cases to Broca's area, fundamental to language.

History

Brodmann's areas are named after the German scientist who first described and classified them: Korbinian Brodmann, a psychiatrist who believed that the cerebral cortex could be divided systematically, with the aim of identifying its specific regions more easily as was being done up to that point.

Brodmann's division of the cerebral cortex was not done randomly, but responded to certain existing differences in terms of the structure, composition and organization of neurons in different areas of the neocortex.

Based on them, the author wanted to better understand what functions each part of the brain played both in healthy individuals and in the case of certain pathologies.

In this way, Brodmann wanted to topographically classify the different areas existing in the brain, with the aim of being able to apply this new knowledge in areas such as psychopathology or the study of cortical functions. To do this, he studied many different animal species, although ultimately his classification only works in the case of primate and human brains.

Other researchers have created alternative or more detailed classifications, such as the one made by Constantin von Economo and Georg N. Koskinas in 1925. However, no other has achieved such a high popularity as that of Brodmann, which has been used in countless cases. investigations and has become the benchmark in its area.

Although the original classification was only based on anatomical and structural differences, recent advances in neuroscience have shown that in the vast majority of cases these also correlate with different functions within brain activity.

The 47 areas, features and functions

As Brodmann discovered in his research, the different parts of the neocortex fulfill different functions on a physical and mental level. In addition to this, the areas are usually organized into groups that share a similar characteristic, or that affect a specific area of ​​brain function.

For example, there are several areas related to vision that are concentrated in a single point in the brain. The same is true for other functions, such as touch, movement, or hearing.

Here is a brief description of each of the 47 original areas that Brodmann described in 1909.

Area 1

The first area described by Brodmann is located next to the Roland fissure, also known as the central sulcus. It is located within the primary somatosensory cortex, and as such plays a role in the reception and processing of tactile and proprioceptive information from different parts of the body.

Area 2

Like area 1, this is also included within the primary somatosensory cortex. Its functions are very similar to those of the previous one; in fact, it has not yet been possible to determine precisely where the limits of each of them are.

Area 3

It is the last area described by Brodmann to be located within the primary somatosensory cortex. Again, it receives and works with the information sent by the organs in charge of detecting tactile stimuli or the internal state of the body.

Area 4

The fourth area described by Brodmann is mainly related to the primary motor area of ​​the brain. This area is essential for movement, as it is responsible for sending the muscles the orders that make them contract or expand.

Area 5

This area of ​​the brain is included within the secondary somatosensory area. Thus, it fulfills a peripheral role within the processing of information sent by the tactile and proprioceptive organs.

Area 6

In zone 6 the premotor function is located. It is responsible for allowing us to plan the movements that we are going to carry out before sending the instructions to the primary area; and within it our default movement patterns are stored.

Area 7

Area 7 is also included within the secondary somatosensory cortex. In this way, it helps with the integration and processing of the information that will then be sent to the primary school. In addition, it also has an important function within the recognition of sensory stimuli.

Area 8

Area 8 is included within the secondary motor cortex. Specifically, it has an especially relevant function within the movement of the eye muscles.

Area 9

The ninth area described by Brodmann is within the dorsolateral prefrontal lobe. Like all structures located in this area of ​​the brain, it has to do with higher mental functions, such as self-awareness, memory, empathy, emotional management and information processing.

In addition, it also plays a certain role at the motor level, especially helping to achieve good verbal fluency.

Area 10

Area 10 is also part of the prefrontal cortex. Due to this, it plays an important role in aspects such as memory, the division of attention, planning and introspection.

Area 11

The area 11 described by Brodmann is also part of the prefrontal cortex, although in this case it is a tertiary association zone. It is related to higher cognitive functions, such as the management of social interactions and the regulation of behavior and emotions.

Area 12

Like 11, area 12 is part of the orbitofrontal lobe, thus being related in the same way to higher cognitive functions.

Area 13

This area is hidden from the naked eye within the insula, specifically in the anterior part of it. It has functions related to language, such as the coordination of the movements of the speech system. It also plays a fundamental role in connecting the limbic system with the prefrontal cortex.

Area 14

Like the previous zone, the 14 also has to do with certain emotional and sexual functions; and in addition, it is related to the processing of visceral information and that coming from smell.

Area 15

It has to do with the regulation of blood pressure. It was one of the few that Brodmann failed to locate in the human brain, although she did in certain apes; and later, other researchers were able to locate it in people.

Area 16

Like zone 14, this is also part of the insula. In this case, it is related to areas as important as the regulation of body temperature, pain, or the ability to swallow.

Area 17

This is the primary visual area. As such, it performs very important functions when deciphering information from the eyes, such as that related to movement, orientation or color. It also has a mapping of the eye, something fundamental for this sense.

Area 18

Area 18 is part of the secondary visual cortex. It helps 17, regulates three-dimensional vision, and plays a very important role in detecting the intensity of light.

Area 19

Like the previous one, it is also one of the secondary visual cortices. It serves to recognize visual stimuli, by relating them to the information stored in memory.

Area 20

It is related to the ventral visual pathway. It allows us to recognize what we are seeing, by recognizing above all shapes and colors. It is located in the area of ​​the inferior temporal gyrus.

Area 21

It is an auditory association area, which is part of the well-known Wernicke area. As such, it plays a very important role in understanding oral language.

Area 22

Although zone 21 is also related to it, zone 22 is the one that makes up most of the Wernicke area. Its function is to understand language, through the interpretation of sound stimuli and their relationship with their meaning.

Area 23

It is included within the area of ​​the cerebral cortex that has to do with memory and feelings. It bears some relation to the limbic system.

Area 24

It has to do with the perception of emotions and their processing. It also has a certain link with behavior, connecting the limbic system with the orbitofrontal cortex.

Area 25

It is located in the subgenual area, relatively close to the cingulum. It has to do with different aspects of the functioning of the body, with sleep, with hunger, and with the regulation of mood.

Area 26

Area 26 is believed to be primarily concerned with the creation and storage of autobiographical memory.

Area 27

In the same way as area 26, area 27 also has to do with memory, in part due to its location close to the hippocampus. It also plays an important role in the recognition of odors, being in its interior part of the primary olfactory cortex.

Area 28

Like the previous two, zone 28 participates both in certain processes related to the sense of smell and in others that allow memory. It also serves as a bridge between the hippocampus and the rest of the brain.

Area 29

This area has to do with the memory of personal experiences and experiences, also forming part of Brodmann's group of areas that have to do with memory. It is located in the retrosplenial area of ​​the cingulate.

Area 30

Like 29, zone 30 has to do with memory; but her relationship with it is a little different, being involved in functions such as learning and the processes of operant and classical conditioning.

Area 31

It is located in the gyrus of the cingulum. It is one of the areas that relate memory to feelings, being the main one in charge of producing the feeling of familiarity that we experience when facing something known.

Area 32

Area 32 is located between the frontal and parietal lobes. It has to do with higher mental processes like the inhibition of automatic responses and the ability to make decisions.

Area 33

Area 33 also has to do with decision-making, but it also fulfills roles in other functions such as pain perception, planning of physical behavior, and the ability to interpret our own feelings.

Area 34

Within area 34 we find the uncus, which means that it is mainly related to the sense of smell. Specifically, it has to do with memory related to smells, and with the perception of unpleasant elements in our environment.

Area 35

Area 35 is concerned with various functions, such as non-conscious memory memory, visual pattern recognition, and certain components of olfactory memory.

Area 36

Brodmann's area 36 is within the group of those that fulfill functions related to autobiographical memory. It also has some importance in the processing of data related to the spatial location of the body. Inside we find the parahippocampal cortex.

Area 37

Inside it is located the fusiform gyrus. It is responsible for the processing of information from different senses at the same time. In addition, it helps perform complex tasks, such as interpreting sign language, recognizing faces, or understanding metaphors.

Area 38

It has to do with the processing of information based on semantics. It also serves as a means of connection between the areas that are responsible for memory and those more related to emotions.

Area 39

Brodmann's area 39 is related to the understanding of language, regardless of whether we receive it in writing or orally. Inside it is the angular turn.

Area 40

Within area 40 is the supramarginal gyrus. This means that it plays an important role in the linking of phonemes and graphemes, making it one of the most important to allow mastering reading and writing. It is also important for motor and tactile recognition.

Area 41

It corresponds to the primary auditory cortex, the first part of the brain that receives information from the ears. Its main function is to perceive changes in frequency, in addition to allowing to locate the origin of sounds.

Area 42

As part of the secondary auditory cortex, it supports area 41 in processing stimuli from the ears. It is complementary to Wernicke's area.

Area 43

Area 43 plays a very important role in the processing of information that comes from the sense of taste. As such, it allows us to identify the different types of flavors of what we eat.

Area 44

Area 44 is the first to be part of Broca's area, one of the most important in the production of language. It has to do mainly with gesticulation, with the intonation of language, and with the movements of the speech system.

Area 45

Like area 44, area 45 is also part of Broca's area. It is mainly related to semantic processing, in addition to fulfilling auxiliary roles in intonation, the production of facial expressions, and gesticulation.

Area 46

It is located within the dorsolateral prefrontal lobe. As such, it is related to abilities such as working memory and attention.

Area 47

The last area described by Brodmann is also part of Broca's area. Its role is to help understand and produce syntax in language and music.

References

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4. "The 47 Brodmann areas, and the brain regions they contain" in: Psychology and Mind. Retrieved on: June 19, 2019 from Psychology and Mind: psicologiaymente.com.
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