What are the frontal lobes of the brain responsible for? Functions of the occipital lobe of the brain

The brain is the main regulator of all body functions. It refers to one of the elements of the central nervous system. Its structure and functions have been the main subject of medical study for a long time. Thanks to their research, it became known what the brain is responsible for and what departments it consists of. Let's dwell on all this in more detail.

The structure of the brain

Before you know what the brain does, you should familiarize yourself with its structure. It consists of the cerebellum, brainstem, and cortex, the latter forming the left and right hemispheres. They, in turn, are divided into the following lobes: occipital, temporal, frontal and parietal.

Brain Functions

Now let's focus on the functions of the brain. Each of its departments is responsible for certain actions and reactions of the body.

parietal lobe

The parietal lobe allows a person to determine their spatial position. Its main task is the processing of sensory sensations. It is the parietal lobe that helps a person to understand which part of his body was touched, where he is now, what he is experiencing in relation to space, and so on. In addition, the parietal lobe has the following functions:

• responsible for the ability to write, read, etc.;
• controls human movements;
• responsible for the perception of pain, heat and cold.

frontal lobe

The frontal lobe of the brain has various functions. She is responsible for:

• abstract thinking;
• Attention;
• ability to solve problems independently;
• desire for initiative;
• critical self-assessment;
• self-control.

The frontal lobe also houses the speech center. In addition, it controls urination and the formation of the body. The frontal lobe is responsible for the transformation of memories into a person's long-term memory. At the same time, its effectiveness is reduced if attention is concentrated simultaneously on several objects.

At the top of the frontal lobe is Broca's area. It helps a person find the right words during conversations. Therefore, those people who have been injured in Broca's area often have problems expressing their thoughts, but they clearly understand what others are saying to them.

The frontal lobe is directly involved in thinking about memories, helping a person to comprehend them and draw conclusions.

temporal lobe

The main function of the temporal lobe is the processing of auditory sensations. It is she who is responsible for converting sounds into words understandable to humans. The temporal lobe contains an area called the hippocampus. It is responsible for long-term memory and is involved in the development of a number of types of epileptic seizures. Therefore, if a person was diagnosed with temporal lobe epilepsy, it means that the Hippocampus is affected.

Occipital lobe

The occipital lobe contains several neuronal nuclei, so it is responsible for:

• vision. It is this lobe that is responsible for the susceptibility and processing of visual information. She also controls the work of the eyeballs. Therefore, damage to the occipital lobe causes partial or complete loss of vision.
• visual memory. Thanks to the occipital lobe, a person can easily assess the shape of objects and the distance to them. When it is damaged, the functions of binocular vision are impaired, as a result, the ability to navigate in an unfamiliar environment is lost.

brain stem

It should immediately be said that the brain stem is formed from the medulla oblongata and midbrain, as well as the bridge. There are 12 pairs of cranial nerves in total. They are responsible for:

• swallowing
• eye movement;
• the ability to perceive tastes;
• hearing;
• vision;
• smell.

Another important function of the brainstem is the regulation of breathing. It is also responsible for the human heartbeat.

Cerebellum

Now let us dwell on which function belongs to the cerebellum. First of all, he is responsible for the balance and coordination of human movement. It also signals the central nervous system about the position of the head and body in space. When it is damaged, the smoothness in the movement of the limbs is disturbed in a person, slowness of actions and poor speech are observed.

In addition, the cerebellum is responsible for regulating the autonomic functions of the human body. After all, it contains a significant number of synoptic contacts. This part of the brain is also responsible for muscle memory. Therefore, it is so important that there are no violations in his work.

Cortex

The cerebral cortex is divided into several types: new, old and ancient, the last two are combined and make up the limbic system. Sometimes an interstitial bark is also isolated, consisting of an intermediate ancient and an intermediate old bark. The new cortex is represented by convolutions, nerve cells and processes. It also contains several types of neurons.

The cerebral cortex has the following functions:

• provides a connection between the lower and higher lying brain cells;
• corrects violations of the functions of systems that interact with it;
• controls consciousness and personality traits.

Of course, the brain has many important functions. Therefore, you should monitor his health and undergo an annual examination. After all, many human diseases are directly related to pathologies that occur in the brain regions.

Read about the work and purpose of the brain in the articles: and. Also, if you are interested in anatomy, check out the content of the article.

The frontal lobes are located in front of the brain, in front of each cerebral hemisphere and in front of the parietal lobes. They are considered the most important region because of their functions and because they take up one third of the total volume of the brain. In other species, their volume is lower (chimpanzees 17% and dogs 7%). They play a role in movement control as well as higher-level mental function, behavior, and emotional control.

Structure and location

The frontal lobes are divided into two main areas: the motor cortex and the prefrontal cortex. The area of ​​the brain involved in language and speech, known as Broca's area, is located in the left frontal lobe.

The prefrontal cortex is the front of the frontal lobes and controls complex cognitive processes such as memory, planning, reasoning, and problem solving.

This area of ​​the frontal lobes helps to set and maintain goals, contain negative impulses, organize events in temporal order, and shape individual personalities.

Functions of the frontal lobes

The frontal lobes regulates motivational processes. They are also responsible for the perception and resolution of conflicts, as well as constant attention, control of emotions and social behavior. They regulate emotional processing and control behavior based on context.

Functions of the premotor cortex

The main function of the motor cortex is to control voluntary movement, including in expressive language, writing, and eye movement. The primary motor cortex sends commands to neurons in the brainstem and spinal cord. These are responsible for specific voluntary movements. Inside the primary motor cortex of the two hemispheres there is a representation of the contralateral half of the body. That is, in each hemisphere there is a representation of the opposite side of the body. This area controls preparation and movement programming. The premotor cortex automates, harmonizes and archives movement programs related to previous experience.

The primary motor cortex of the frontal lobes is involved in voluntary movement. It has nerve connections to the spinal cord that allow this area of ​​the brain to control muscle movement. Movement in different areas of the body is controlled by the primary motor cortex, with each area associated with a specific area of ​​the motor cortex. Parts of the body that require fine control of movement take up large areas of the motor cortex, while those that require simpler movements take up less space. For example, areas of the motor cortex that control movement of the face, tongue, and arms take up more space than areas associated with the hips and trunk. The premotor cortex of the frontal lobes has neural connections to the primary motor cortex, the spinal cord, and the brain stem. The premotor cortex allows you to plan and execute the right movements in response to external signals. This cortical area helps determine the specific direction of movement.

Functions of the prefrontal cortex

The prefrontal cortex is located in front of the frontal lobe. It is considered the ultimate expression of the development of the human brain. It is responsible for cognition, behavior and emotional activity. The prefrontal cortex receives information from the limbic system (involved in emotional control) and acts as an intermediary between cognition and feeling through executive functions. Executive functions are a set of cognitive skills required to control and self-regulate behavior.

Functions of the Dorsolateral Prefrontal Cortex

It is one of the most recently formed parts of the human brain. It establishes connections with three other areas of the brain and transforms information into thoughts, decisions, plans and actions.

It is responsible for cognitive abilities such as:

• Attention;
• focus;
• braking;
• maintenance and processing of information;
• programming upcoming actions;
• analysis of possible results;
• introspection of cognitive activity;
• analysis of the situation and development of an action plan;
• ability to adapt to new situations;
• organization of behavior towards a new goal.

Frontal lobes and related disorders

The frontal lobes are involved in various processes (cognitive, emotional, behavioral). This is why lesions caused by injuries inflicted on this area can range from concussion symptoms to others that are more severe.

Damage to the frontal lobe can lead to a number of difficulties such as loss of fine motor function, speech and language difficulties, thinking difficulties, inability to understand humor, lack of facial expression, and personality changes.

Damage to the frontal lobe can also lead to dementia, memory impairment, and lack of impulse control.

Types and features of disorders in trauma

Damage to the primary or premotor cortex can cause difficulty in coordinating speed, execution, and movement, leading to various types of apraxia. is a disorder in which a person has difficulty planning movement to complete tasks, provided that the request or command is understandable and he/she is willing to complete the task. Ideomotor apraxia is a deficit or difficulty in the ability to plan or perform previously learned motor actions, especially those that require an instrument. Affected people can explain how to perform actions, but cannot act. Kinetic apraxia: voluntary movements of the limbs are disturbed. For example, people cannot use their fingers in a coordinated way (playing the piano). In addition to apraxia, other disorders can develop from frontal lobe injuries, such as language disorders or aphasias. Transcortical motor aphasia: A language disorder in which a person lacks verbal fluency (slow speech with reduced content and poorly organized), limited spontaneous language (lack of initiative), and difficulty or disability in writing. Brock: a language disorder that produces a lack of verbal fluency, anomie (inability to access vocabulary to name words), poor syntactic construction in speech, difficulty repeating, reading and writing. However, the symptoms will depend on the damaged area.

Dorsolateral region and injuries

Trauma in this area is usually associated with cognitive problems such as:

1. Inability to solve complex problems: decreased flexibility (reasoning, adapting and solving new situations, etc.).
2. Cognitive rigidity and persistence: A person maintains a thought or action despite a suggestion to change the thought or action.
3. Decreased learning ability: Difficulties in acquiring and maintaining new information.
4. Memory impairment.
5. Deficiency in programming and change in motor activity: difficulties in organizing the sequence of movements and changing activity.
6. Decreased verbal fluidity: deterioration in the ability to remember words. This action requires not only the lexical part, but also organization, planning, focus and selective attention.
7. Attention Deficit: Difficulty maintaining attention and obstructing other irrelevant stimuli or changing the focus of attention.
8. Pseudo-depressive disorders: symptoms of depression (sadness, apathy, etc.).
9. Decreased spontaneous activity, loss of initiative and motivation: marked apathy.
10. A: Difficulty identifying emotions and therefore inability to express one's own emotions.
11. Language restriction: answers are usually one-syllable.

Orbital region and injuries

Symptoms of injury in this area are more behavioral. Human behavior tends to be disinhibited (similar to what happened to Phineas Gage, who experienced negative personality changes after a head injury):

1. Irritability and aggressiveness: exaggerated emotional reactions in daily life.
2. Echopraxia: imitation of observed movements.
3. Termination and impulsivity: lack of self-control over behavior.
4. Difficulty adapting to social norms and rules: socially unacceptable behavior.
5. Violation of judgment.
6. Lack of empathy: difficulty understanding the feelings of others.

The frontal lobes are incredibly important for people to operate at their full potential. Even without brain injury, it is critical to keep cognitive skills active—brain health is essential for a fulfilling life.

The frontal lobe of the brain is of great importance for our consciousness, as well as such functions as spoken language. It plays a vital role in memory, attention, motivation and a host of other daily tasks.

The structure and location of the frontal lobe of the brain

The frontal lobe is actually made up of two paired lobes and makes up two-thirds of the human brain. The frontal lobe is part of the cerebral cortex, and the paired lobes are known as the left and right frontal cortex. As the name suggests, the frontal lobe is located near the front of the head under the frontal bone of the skull.

All mammals have a frontal lobe, although they vary in size. Primates have the largest frontal lobes of any other mammal.

The right and left hemispheres of the brain control opposite sides of the body. The frontal lobe is no exception. Thus, the left frontal lobe controls the muscles on the right side of the body. Similarly, the right frontal lobe controls the muscles on the left side of the body.

Functions of the frontal lobe of the brain

The brain is a complex organ with billions of cells called neurons that work together. The frontal lobe works along with other areas of the brain and controls the functions of the brain as a whole. The formation of memory, for example, depends on many areas of the brain.

What's more, the brain can "repair" itself to compensate for damage. This does not mean that the frontal lobe can recover from all injuries, but other areas of the brain can change in response to head trauma.

The frontal lobes play a key role in future planning, including self-management and decision making. Some functions of the frontal lobe include:

1. Speech: Broca's area is an area in the frontal lobe that helps to verbalize thoughts. Damage to this area affects the ability to speak and understand speech.
2. Motor skills: The frontal cortex helps coordinate voluntary movements, including walking and running.
3. Object Comparison: The frontal lobe helps classify objects and compare them.
4. Memory shaping: Almost every area of ​​the brain plays an important role in memory, so the frontal lobe is not unique, but it plays a key role in the formation of long-term memories.
5. Personality formation: The complex interplay of impulse control, memory, and other tasks helps shape the basic characteristics of a person. Damage to the frontal lobe can radically change personality.
6. Reward and motivation: Most of the dopamine-sensitive neurons in the brain are located in the frontal lobe. Dopamine is a brain chemical that helps maintain feelings of reward and motivation.
7. attention management, including selective attention: when the frontal lobes cannot control attention, it can develop(ADHD).

Consequences of damage to the frontal lobe of the brain

One of the most infamous head injuries happened to railway worker Phineas Gage. Gage survived after an iron spike pierced the frontal lobe of the brain. Although Gage survived, he lost an eye and a personality disorder occurred. Gage changed dramatically, the once meek worker became aggressive and out of control.

It is not possible to accurately predict the outcome of any injury to the frontal lobe, and such injuries can develop quite differently in each person. In general, damage to the frontal lobe due to a blow to the head, stroke, tumors, and diseases can cause the following symptoms, such as:

1. speech problems;
2. personality change;
3. poor coordination;
4. difficulty with impulse control;
5. planning problems.

Treatment of damage to the frontal lobe

Treatment of damage to the frontal lobe is aimed at eliminating the cause of the injury. A doctor may prescribe drugs for an infection, perform surgery, or prescribe medications to reduce the risk of a stroke.

Depending on the cause of the injury, treatment is prescribed that may help. For example, with frontal injury after a stroke, it is necessary to switch to a healthy diet and physical activity in order to reduce the risk of stroke in the future.

Drugs may be useful for people who have impaired attention and motivation.

Treatment of frontal lobe injuries requires ongoing care. Recovery from injury is often a lengthy process. Progress can come suddenly and cannot be fully predicted. Recovery is closely linked to supportive care and a healthy lifestyle.

Literature

1. Collins A., Koechlin E. Reasoning, learning, and creativity: frontal lobe function and human decision-making //PLoS biology. - 2012. - T. 10. - No. 3. - S. e1001293.
2. Chayer C., Freedman M. Frontal lobe functions //Current neurology and neuroscience reports. - 2001. - T. 1. - No. 6. - S. 547-552.
3. Kayser A. S. et al. Dopamine, corticostriatal connectivity, and intertemporal choice //Journal of Neuroscience. - 2012. - T. 32. - No. 27. - S. 9402-9409.
4. Panagiotaropoulos T. I. et al. Neuronal discharges and gamma oscillations explicitly reflect visual consciousness in the lateral prefrontal cortex //Neuron. - 2012. - T. 74. - No. 5. - S. 924-935.
5. Zelikowsky M. et al. Prefrontal microcircuit underlies contextual learning after hippocampal loss // Proceedings of the National Academy of Sciences. - 2013. - T. 110. - No. 24. - S. 9938-9943.
6. Flinker A. et al. Redefining the role of Broca's area in speech //Proceedings of the National Academy of Sciences. - 2015. - T. 112. - No. 9. - S. 2871-2875.

The premotor sections of the cerebral cortex are part of the third, main block of the brain, which provides programming, regulation and control of human activity.

As is known, the frontal lobes of the brain, and in particular their tertiary formations (which include the prefrontal cortex), are the most recently formed part of the cerebral hemispheres.

It is known that for the course of any mental processes a certain tone of the cortex is necessary and that the level of this tone depends on the task set and on the degree of automation of the activity. The regulation of activity states is the most important function of the frontal lobes of the brain.

As mentioned above, the state of active expectation of a signal is accompanied by the appearance in the frontal regions of the brain of slow bioelectrical activity, which Gray Walter called the “waiting wave” (see Fig. 36). Intellectual activity also leads to a significant increase in the number of synchronously operating excited points in the frontal parts of the brain (see Fig. 37).

It is natural to expect that in a pathological state of the frontal cortex, the mechanisms of emergency activation mediated by speech should be disturbed.

The frontal lobes of the brain, which play such a significant role in the regulation of the optimal tone of the cortex, are the apparatus that ensures the formation of persistent intentions that determine the conscious behavior of a person. Even with the most superficial observation of the general behavior of patients with massive lesions of the frontal lobes of the brain, a violation of their plans and intentions becomes obvious.

In the anterior part of each cerebral hemisphere is the frontal lobe (lobus frontalis). It ends in front with the frontal pole and is bounded from below by the lateral groove (sulcus lateralis; sylvian furrow) and behind a deep central furrow. The central sulcus (sulcus centralis; Roland's sulcus) is located in the frontal plane. It begins in the upper part of the medial surface of the cerebral hemisphere, cuts across its upper edge, descends without interruption along the upper-lateral surface of the hemisphere down and ends a little before reaching the lateral groove.

Anterior to the central sulcus, almost parallel to it, is the precentral sulcus (sulcus precentralis). It ends at the bottom, not reaching the lateral furrow. The precentral sulcus is often interrupted in the middle part and consists of two independent sulci. From the precentral sulcus, the upper and lower frontal sulci (sulci frontales superior et inferior) go forward. They are located almost parallel to each other and divide the upper-lateral surface of the frontal lobe into convolutions. Between the central sulcus at the back and the precentral sulcus at the front is the precentral gyrus (gyrus precentralis). Above the superior frontal sulcus lies the superior frontal gyrus (gyrus frontalis superior), which occupies the upper part of the frontal lobe. Between the upper and lower frontal sulci stretches the middle frontal gyrus (gyrus frontalis medius).

Down from the inferior frontal sulcus is the inferior frontal gyrus (gyrus frontalis inferior). The branches of the lateral sulcus protrude into this gyrus from below: the ascending branch (ramus ascendens) and the anterior branch (ramus anterior), which divide the lower part of the frontal lobe, hanging over the anterior part of the lateral sulcus, into three parts: tegmental, triangular and orbital. Tire part (frontal tire, pars opercularis, s. operculum frontale) is located between the ascending branch and the lower part of the precentral sulcus. This part of the frontal lobe got its name because it covers the insular lobe (islet) lying deep in the furrow. The triangular part (pars triangularis) is located between the ascending rear and the anterior branch in front. The orbital part (pars orbitalis) lies downward from the anterior branch, continuing to the lower surface of the frontal lobe. In this place, the lateral groove expands, and therefore it is called the lateral fossa of the brain (fossa lateralis cerebri).

The function of the frontal lobes is associated with the organization of voluntary movements, the motor mechanisms of speech and writing, the regulation of complex forms of behavior, and thought processes.

The afferent systems of the frontal lobe include conductors of deep sensitivity (they end in the precetral gyrus) and numerous associative connections from all other lobes of the brain. The upper layers of the cells of the cortex of the frontal lobes are included in the work of the kinesthetic analyzer: they are involved in the formation and regulation of complex motor acts.

Various efferent motor systems begin in the frontal lobes. In the fifth layer of the precentral gyrus, there are gigantopyramidal neurons that make up the cortical-spinal and cortical-nuclear pathways (pyramidal system). From the vast extrapyramidal sections of the frontal lobes in the premotor zone of its cortex (mainly from the cytoarchitectonic fields 6 and 8) and its medial surface (fields 7, 19) there are numerous conductors to the subcortical and stem formations (fronto-thalamic, fronto-palpidary, frontonigral, fronto-rubral, etc.). In the frontal lobes, in particular in their poles, the fronto-bridge-cerebellar pathways begin, which are included in the system of coordination of voluntary movements.

These anatomical and physiological features explain why, in lesions of the frontal lobes, mainly motor functions are disturbed. In the sphere of higher nervous activity, the motor skills of the speech act and behavioral acts associated with the implementation of complex motor functions are also disturbed.

The entire cortical surface of the frontal lobe is anatomically divided into three components: dorso-lateral (convexital), medial (forming the interhemispheric fissure) and orbital (basal).

The anterior central gyrus contains motor projection areas for the muscles of the opposite side of the body (in the reverse order of its location on the body). In the posterior section of the second frontal gyrus, there is a "center" for turning the eyes and head in the opposite direction, and in the posterior section of the inferior frontal gyrus, Broca's area is localized.

Electrophysiological studies have shown that premotor cortex neurons can respond to visual, auditory, somatic, olfactory, and gustatory stimuli. The premotor region is able to modify motor activity through its connections to the caudate nucleus. It also provides the processes of sensory-motor relationships and directed attention. The frontal lobes in modern neuropsychology are characterized as a block of programming, regulation and control of complex forms of activity.