How much of the brain is unknown?

In this brief guide we are going to answer the question ‘’How much of the brain is unknown?’’ Today we open the curtain to review some of the enigmas about this complex organ that science has not yet been able to solve.

How much of the brain is unknown?

We know very little about the brain. In fact, It’s estimated that we know 15% of the primary visual cortex. Every time we discover more areas, but there is still much to solve.

It’s one of the most complex organs in the human body. It’s part of the Central Nervous System (CNS), weighs just over 3 pounds (representing just 2% of body weight) and receives approximately 25% of the total blood that pumps the engine of our body, the heart.

The brain remains a great unknown. Although the functioning of neurons and the brain in general has been studied for more than 100 years, we still know very little about their functioning, in relation to what we know about other vital organs of animals and humans.

Billions of millions are being invested to better understand the keys to its operation through the Human Brain Project and the Brain Initiative, but even so we still have a lot to know, for example in aspects such as what the memory process really consists of and oblivion

The cortex is the outer layer of the brain, which concentrates functions related to language, sensory perception and abstract thinking, among others.

The map prior to this was made in the early 20th century. Back then, Korbinian Brodmann identified 47 regions involved with language and sensory processing.

Unknown areas of the brain

A team of neuroscientists has created an accurate map of 180 areas of the cerebral cortex -97 of them unknown until now- using software that has incorporated data from multiple types of MRI images. According to the authors, the findings could be applied to improving brain surgery and researching human cognitive evolution.

Maps of the brain may abound, but the reality is that each advance shows that it’s still a great unknown, and the work of experts from the University of Washington, published in Nature, proves it.

Not only because they have discovered 97 new areas of the cerebral cortex, the outermost layer of the brain, involved in sensory perception, language, the use of tools and abstract thinking.

But also because the amount of information obtained is enormous. “We had to convince Nature -explains David Van Essen, one of the authors of the study- to upload some 200 extra pages of each of the 180 regions studied to its website, as well as the algorithms we used to create the map.

“We believe that this information will serve the scientific community to explore the map on their own and obtain new data.”

Application

To carry out this daunting task, researchers at the University of Washington School of Medicine have turned to data generated by the Human Connectome Project, a multi-million dollar five-year study led by Van Essen himself and using a powerful MRI machine, created specifically for this project, to map the brains of 1,200 adults.

The authors used brain information from 210 young adults of both genders and divided the brain into 180 areas of both the left and right hemispheres based on physical  (such as the thickness of the cortex), functional (areas that respond to language stimuli) and differences in the connectivity of certain regions.

Brain mapping is not as simple as a geographic map, since most of the brain is superficially very similar. At the level of the crust, it has more to do with a border map: certain differences cannot be seen from the air and take on new details when they are covered “on foot”.

What new information does this project bring to the table?

“The brain is not like a computer that can run any operating system and use any software,” says Van Essen. The brain’s software, how it works, is initially correlated with the structure of the brain (its hardware). If we want to find out what the brain can do, we must understand how it’s organized and connected.

Thanks to this, experts have discovered areas as specific as 55b, the “Storytelling” region, since it’s activated when a person hears a story. Others contain a map of the field of view or are involved in movement control.

Despite this, it’s likely that most zones will never be identified with a single function because they are not limited to one task, but coordinate information from many different signals.

“Although we have reached 180 areas in each hemisphere, we hope it’s not the final number – concludes Matthew Glasser, another of the lead authors -. We have identified parts of the crust that are likely to be subdivided, but we cannot set the boundaries for sure with current techniques and data … ”

”In the future it may be possible, with new or better technologies. We have focused on those on which we are sure of the data obtained ”. So that other researchers can also delve into these maps, the experts have also developed software that automatically detects the fingerprint of each of these new areas in brain scans.

And it’s that, like the cartographers of the past, the experts who map the human brain, create tools for other explorers to use them in new discoveries.

Unsolved mysteries about the brain

This complex organ remains a nest of mysteries that neuroscience constantly delves into.

In fact, over the last decade we have learned more about the human brain than in the entire remaining history of humanity thanks to multiple advances and development of technologies such as functional magnetic resonance imaging machines, as well as various research and studies.

Next we will take a look at five mysteries of the brain that science has not yet been able to solve and that today constitute a magnetic challenge for the scientific community.

How is information encoded in neural activity?

Neurons produce small electrical discharges in their membranes, which travel through axons to release chemical signals. This is where all the things we feel are, but how does this encoding work? They mean different things depending on where in the brain and time: for example, in the peripheral nervous system, more spikes indicate more heat.

However, there are certain groups of neurons involved in more complex phenomena that make neuronal activity more difficult to understand. It’s not yet well known which part of the brain is involved in each of these processes, although it’s thought that neurons act in groups and not individually.

Nerve impulses may not be the only way information is transmitted.

How are memories saved and retrieved?

When you learn something new, there are changes in the structure of the brain, however, it’s not known exactly how this change works and what consequences it has.

Another problem is that there are several types of memories: short and long term, and within the second, declarative memory -names and facts- and non-declarative memory – such as riding a bicycle. Despite the differences, there appears to be a common molecular mechanism.

When neurons fire together, the connection between them is stronger and associations are created. However, when the brain creates those associations, the relationships between things are encoded and not the details.

Scientists don’t know exactly what happens in that neuron to store memory, or how to dissolve that synaptic connection if you want to forget something.

Even more mysterious is the fact of how we remember things through a quick process, some memories are modified or erased. Recent studies show that some chemicals can block and modify memory.

How does the brain simulate the future?

Simulating the future is one of the smartest things our brain does. It’s not known how the brain manages to do this simulation. It’s supposed to be related to the creation of models and their contrast with memory. At the moment it’s unknown what are the mechanisms that make this type of simulation possible.

This is believed to work by creating an internal model of the outside world and how things behave in it, thanks to memory and past experiences.

Time perception

It seems that the brain has some difficulty processing events that occur simultaneously. This occurs when two or more events happen at different speeds.

The senses process things differently, but the brain tries to make you see them as simultaneous.

Without a doubt, the passage of time, simultaneity and the like are constructions of our brain. Lack of synchrony can lead to problems such as dyslexia or falls in older people.

Why does the brain sleep and dream?

The act of sleeping and dreaming has always been associated with rest. However, in recent decades it has been discovered that the brain remains very active during sleep. In fact, there are times when you work harder than when the person is awake.

Almost all animals tend to sleep, and lack of sleep leads to negative health consequences. However, it’s not known for sure what the function of sleeping is: it’s believed that it can be regenerative, but the truth is that there is a large amount of neural activity that can mean something else.

Other theories say that sleep is a time for the brain to solve problems before doing it in the real world; or that the dream is the moment when knowledge is fixed.

What is consciousness?

Scientists don’t know where the brain ends and the mind begins. Are they the same thing? Does the soul exist? Is it located if so in our brain? What is responsible for all the unique thoughts and feelings that make us who we are?

Everyone from philosophers to physicists has addressed this question of consciousness, a very subjective and difficult concept to quantify.

To delve into the empirical part of this question, scientists have used brain imaging to observe how different parts of the brain light up, although it’s not yet known at what stage of the process a neuron becomes or drifts into conscious thought.

So, How much of the brain is unknown?

We know quite little about the brain. It’s a system that many of us think is the most complex in the universe. It’s estimated that we know 15% of the primary visual cortex.

We have studied the brain for decades and have learned a lot, but not enough to solve some of its problems, particularly those of medicine, such as depression or alcohol addiction,

Although a lot of progress has been made in neuroscience, there are still many puzzles to solve around the functioning of the human brain. It’s not for less, if one takes into account that it’s a very complex organ and that it’s the organ itself that is applied in the extraordinary task of knowing itself.

FAQS: How much of the brain is unknown? 

In this brief guide we answered the question ‘’How much of the brain is unknown?’’ Today we opened the curtain to review some of the enigmas about this complex organ that science has not yet been able to solve.

Did you know these 10 mysteries of the brain without scientific explanation? What else would you like to know about how the brain works?

If you have questions or comments please let us know!

References

Adolphs, R. (2015). The unsolved problems of neuroscience. Trends in Cognitive Sciences, 19(4), 173–175. https://doi.org/10.1016/j.tics.2015.01.007‌

brain. (2019, March). 5 unsolved mysteries about the brain. Retrieved October 10, 2020, from Allen Institute website: https://alleninstitute.org/what-we-do/brain-science/news-press/articles/5-unsolved-mysteries-about-brain

Geddes, L. (2016). Human brain mapped in unprecedented detail. Nature. https://doi.org/10.1038/nature.2016.20285

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