The CEO Of The Human Brain

The mammalian brain is a very complex organ.  In human beings, the complexity is significantly increased because of the size of the youngest part of the brain – the cerebral cortex. But the amazing capabilities of the human brain are not dependent on the brain size alone – but also on proper organization, specialization and connections. It is especially true for one of the most important parts of the cerebral cortex – the prefrontal cortex. Let us see why it is so!

The structure of the brain in great apes and humans is relatively similar. But the behavior of a chimpanzee, for example, is still very different from the behavior of an adult Homo sapiens.

We know that an average chimpanzee is able to interact within its group, is able to learn sign language to communicate, and is also known to be able to use tools. But humans can do more. For instance:

• Human beings can retain memories and use them for making deductions and predict how things can unfold;
• Humans can  plan several steps ahead- even for the far-away future;
• Humans can subdue their instincts (such as aggressive behavior or desire to flee in the face of danger), if  necessary;
• Human societies are complex, with a lot of laws, and we are able to navigate them with relative ease.

We must not, of course, forget our other abilities – we have complex speech instead of simple sounds; we can operate with abstract entities – things we have never even seen in our life. Inside our brains, we have those complex tools that allow us to work with various types of information.

Just consider for a minute how much your brain works when you are reading this article! First, you are forcing yourself to hold your position (when maybe you want to jump about). Second, you decipher those strange symbols on the screen as words and attach meaning to each and every one.

By reading through the article, you form memory and learn important information that you would recall and use in the future. You also may remember some old information and add it to the new picture you have built based on everything you have learned.

Moreover, you may also act upon those words – for instance, write your own essay. And yet, you may only imagine what a brain looks like, based on very few clues. That is all abilities that are typical for Homo sapiens only – at least, based on our knowledge so far.

Though all people possess those skills, each individual uses them differently. Some people are likely to make rash decisions, while others plan carefully. Some profess their emotions and thoughts on the subject immediately and publicly-while others keep to themselves. Our manner of expressing ourselves and dealing with the world can be very different.

And this complex web of emotions, decisions and actions that basically determines one’s personality is actually located in one region of the brain – prefrontal cortex (PFC).

Let us digress for a while.

At the end of the 19th and the beginning of 20th centuries studying the brain was not easy. It was near to impossible to determine the functions of more evolved parts of the brain in humans. With the parts of the brain that were evolutionary older, it was easier – after all, they were present in other animals, such as reptiles or mice.

If one wanted to understand what the function of the cerebellum is – he would take some mice to the lab and destroy those parts of their brains and observe how the animals function afterwards. While some people condoned such experiments in animals, in humans it was naturally not supported.

The only way to decipher such mysteries was to observe people with various head traumas – how certain types of damages affected the symptoms those people had.

One of such cases was especially famous.  Phineas Gage, a 25-year old railroad worker, has gotten into an awful accident on September 13, 1848 [1]. While he was working, a metal rod has pierced his head, going straight from the left cheek to the area beside his forehead. Surprisingly, the rod has not damaged any vital spots. The man was saved, and he could move and walk and think. But still, the injury had significantly changed the way the patient used to behave:

• Phineas became fitful and got angry easily;
• He has lost any restraint in conversing with other people;
• He  stopped being able to plan for the future: he constantly had new ideas or plans, but then abandoned them halfway;
• He began to suffer from seizures regularly;

Now, imagine that you are a doctor, a specialist. If you look at those symptoms as a whole, you would see that the common motive here is the lack of balance and restraint and inability to coordinate complex actions like planning or conversing with other people. And it happened because the rod has damaged a crucial area – prefrontal cortex.

Did you know?

Before the Gage case, people thought that the cerebral cortex – the special neural structure with grooves and ridges – was just a big cover protecting the cerebrum and basal ganglia. It was supposed to not have any function at all. But the dramatic personality change in Gage was proof that this area was much more important and complex [1]

What is the prefrontal cortex?

As you can infer from the Gage case, the prefrontal cortex is located literally at the forefront of the brain. It is in the area right behind your forehead [2]. Here is the picture to help you imagine its position:

When specialists talk about the prefrontal cortex, they say it is responsible for so-called executive functions [3]. What does it mean?

Imagine the CEO of the company. He or she may not do any specific labor, but he has to:

• Receive, read and analyze reports from all the departments;
• Control the flow of money in and out of the company;
• Distribute tasks and projects to each department;
• Report to the panel of shareholders;
• Make long-term plans for the future.

The prefrontal cortex does very similar work:

1. It is connected to the other brain areas: the cerebellum, basal ganglia, amygdala, sensory areas, motor areas, etc. Each connection is a two-way road: the information is received, analyzed, and then new instructions are sent back.
2. By “holding the reins” of multiple areas, prefrontal cortex controls:
3. Complex movements (for example, dancing);
4. Social interactions;
5. Long-term planning;
6. Memory formation;
   1. Emotions control and display;
7. Suppression of reactions based on instincts.

In other words, prefrontal cortex controls and rules our interactions with the outside world based on incoming information. It is also basically responsible for our polite behavior by suppressing our instincts and forces us to behave according to the norms of our society.

Even an ape that lives among humans would still behave as it wants unless it is forced to by fear or encouraged to do something by a treat. We behave as required even if there is no immediate threat of punishment. In doing so, we are obeying words or rules ingrained in us a long time ago.

Moreover, we sometimes obey and fear quite abstract threats we have never really experienced – for example, religion-related ones. An ape, even one trained and taught from an early age, would probably not be able to do that.

Basically, the prefrontal cortex controls all three components of our behavior: our thoughts, actions and feelings. As there are a lot of functions to perform, there are certain specialized areas within the prefrontal cortex itself:

Did you know?

Your conscience is hidden in prefrontal cortex, too!  If the prefrontal cortex is underdeveloped in a person, he or she may not be able to feel guilt or remorse. It was recently proven that when people relieve their feelings of guilt connected to past events, their MRI shows several active zones in the prefrontal cortex [4].

Your conscience is hidden in the prefrontal cortex, too!  If the prefrontal cortex is underdeveloped in a person, he or she may not be able to feel guilt or remorse. It was recently proven that when people relieve their feelings of guilt connected to past events, their MRI shows several active zones in the prefrontal cortex [4].

Functional areas of prefrontal cortex

While the CEO is responsible for many things, he or she cannot do everything at once. That is why he/she would have some executive departments and assistants. The same is true for the prefrontal cortex – it contains several specialized areas responsible for certain operations. Those areas are [3]:

Dorsolateral prefrontal cortex (DLPC).

This is the area at the top of the prefrontal cortex. According to specialists, its main roles are:

• Helping the brain make plans;
• Helping with keeping attention on the task at hand;
• Flexibility – This is the go-to area for creative problem solving;
• Working together with the hippocampus and extracting long-term memories needed;
• Managing the working memory;

Interesting to know!

As you remember, there are two hemispheres in the cerebrum – left and right. Their functions are slightly different. For example, the left part of the DLPC works with behaviors that involve approaching objects and situations [3]. If the right DLPC is active instead, it would make the person to avoid the situation [3].

Orbifrontal cortex (OPC).

This area is located below the dorsolateral cortex, approximately on the eye level. It is connected to the limbic system, which influences the type of functions it performs:

• The OPC is responsible for making decisions based on information from emotions (for example, if you feel  pain and anger when seeing a certain person – you would avoid any business or enterprise connected with him or her);
• The OPC is in charge of managing social attachments (choosing how to behave with certain people around you); 
• It also helps us with managing behavior in society (from understanding jokes to leading business talks);
• Moreover, the OPC is also engaged in managing emotions themselves – it can both suppress their expression or
  “let them go”;

Interesting:  Left orbifrontal cortex is associated with negative emotions while the right switches on the positive ones.

Ventromedial prefrontal cortex (VMPC).

This is the lowest area of the prefrontal cortex. Its location makes connections with other brain components easier, so this region is especially well-connected, so to speak. It has links to:

• Amygdala;
• Thalamus;
• Temporal lobe;
• Olfactory system (detection of smells);
• Ventral tegmental area;  

This area is very important because:

• It helps us maintain self-control;
• VMPC is very important for our ability to learn from our mistakes;
• It is also the area involved in feelings of guilt and shame [4], as well as compassion, and even courage (i.e., suppression of fears).

Interesting to know.

Sometimes, connections to amygdala can go the wrong way. It was shown that severe stress can cause the amygdala to produce neurotransmitters that block the regulation of the brain activity by prefrontal cortex. In other words, amygdala, that is in charge of our defensive instincts and emotions takes charge and switches the brain programs from analyzing and suppressing to acting based on our instincts and emotions [5].

Did you know?

In the previous century, the problem of mental patients was a very acute one. Institution were full of patients that were behaving strange, and sometimes were really aggressive. Nobody knew how to treat them. Then, a new method was proposed. According to this new approach, parts of the prefrontal cortex were being surgically removed in mentally ill patients or the connections between prefrontal cortex and other brain areas were destroyed. These procedures were called lobotomy and leucotomy. These procedures were done in hope that the patients would become less aggressive and more manageable.

The surgery was often risky, as the conditions were not particularly safe and sterile. First surgeries sometimes have even involved an icepick! Many died from infection. Those who survived have indeed become more docile – but also were forced to stay at the special institutions in the “state of idle dependency”. [5]. At present, there are far better treatment methods that do not deprive the patients of independence of thought and action.

Development of prefrontal cortex.

It is very hard to become a CEO. Ideally, a good CEO must study extensively and slowly rise to the top, gaining connections and experience. The same happens to the prefrontal cortex. This area needs the most time to develop among all other brain areas: it can be considered finally “ready” only when the person is in his/her late teens [7].

That is why teenagers are so emotional and lack long-term planning skills: their CEOs are simply not ready to take up their jobs. Instead, their amygdala may take the reins, as it does during severe stress. To be completely competent, the prefrontal cortex has to undergo careful “pruning”: some connections between nerve cells has to be cut, while others have to be carefully nurtured to grow the right network [7].

It is now known that if something goes wrong with this careful pruning process and maintaining connections, the person is at risk of developing schizophrenia – a severe mental illness [8]. Such disruptions can happen either in infancy or in the teen years due to either genetic predisposition or influence of the environment [8].

It was discovered that if a certain gene, called  Disrupted-in-Schizophrenia 1 (DISC1) is switched off in the newborn mice, they are likely to have severe defects in their ability to learn and making memories. This is now considered a possible mechanism that is responsible for the development of schizophrenia in humans [9].

Despite the enormous amount of the new data, we still know fairly little about the inner workings of prefrontal cortex. It is only in the last decade, with new genetic and neurological methods, the neurobiologists have started to realize how complex the life of the “CEO of Brain, Ltd.” actually is.

If you risk diving into the relevant literature – you would probably have a hard time going back up. If you do not want to burden yourself with so much technical knowledge – just remember one thing. The CEO of your brain is very hard at work, adjusting, suppressing and inventing. Respect its work. This means eating and resting properly, as well as giving yourself new opportunities for learning and training.

References

1. Garcia-Molina, A. [July-August, 2012]. Phineas Gage and the enigma of the prefrontal cortex. Neurología, V. 27, Issue 6, p. 370-375
2. Hathaway, W. and B. W. Newton [April 8, 2019]. Prefrontal cortex. In: Neuroanatomy. StatPearls Publishing LLC. Retrieved October 2, 2019 from: https://www.ncbi.nlm.nih.gov/books/NBK499919/
3. SoP [Jan 4, 2017]. Prefrontal cortex. The Science of Psychotherapy. Retrieved October 2, 2019 from: https://www.thescienceofpsychotherapy.com/prefrontal-cortex/
4. Michl, P. et al. [February, 2014]. Neurobiological underpinnings of shame and guilt: a pilot fMRI study. Soc. Cogn. Affect. Neurosci. V. 9, № 2, p. 150-157
5. Arnsten, A. F. T.  [June 2009]. Stress signalling pathways that impair prefrontal cortex structure and function. Nat. Rev. Neurosci. V. 10, № 6, p. 410-422.
6. Faria, A. M., Jr. [April 5, 2013]. Violence, mental illness, and the brain – A brief history of psychosurgery: Part 1 – From trephination to lobotomy. Surg. Neurol. Int. , V. 4, p. 49. Retrieved October 3, 2019 from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3640229/
7. Uytun, M. C. [October 3, 2018]. Development period of prefrontal cortex. In: Prefrontal cortex. Ed. Starcevic, A. and B.  Filipovic. Intechopen, 2018. Retrieved from: https://www.intechopen.com/books/prefrontal-cortex/development-period-of-prefrontal-cortex
8. Selemon, L. D. and n. Zelevic [2015] Schizophrenia: a tale of two critical periods for prefrontal cortical development. Translational psychiatry, V. 5., p. e623. Retrieved October 3, 2019 from: https://www.nature.com/articles/tp2015115
9. Xu, X. et al. [February 13, 2019]. Transient knock-down of prefrontal disc1 in immune-challenged mice causes abnormal long-range coupling and cognitive dysfunction throughout development. Journal of  Neuroscience, V. 39, № 7, p. 1222-1235.