The Control Centre in the Body

‘Use your brain and think hard!’ was something that my teachers used to tell me in school. How does this organ in the body control almost EVERYTHING in the body?

This post will discuss what the brain does at three levels of difficulty.

Level 1 (4-9 years old)- What part of the brain does what? (Parents Corner included at the bottom)

Do you ever wonder how an organ (a part of the body with an important job that no other body parts can do) can control the whole body? The brain is a part of the body that gives out orders to other parts of the body (like a command centre) but because the body is bigger than the brain, which part of the brain is in charge of which part of the body? We shall look at one main part of the brain.

The part of the brain that we will look at is called the cerebrum. The cerebrum is a big part of the brain that has many smaller parts. To better understand how each part of the cerebrum works, researchers have divided the cerebrum into 4 main parts: the frontal lobe, parietal lobe, occipital lobe and temporal lobe.

Now let’s answer the question what each part of the cerebrum does:

Frontal lobe: The frontal lobe is mostly known for helping you solve problems. For example, when you plus and minus numbers or think about how to get a ball that is stuck in a bush, the frontal lobe helps you with these activities.

Parietal lobe: The parietal lobe helps us move and focus. When you are walking or jumping around during playtime, the parietal lobe makes sure that you can put one foot in front of the other without falling down.

This part of the brain is also involved in looking hard at certain things that you want to look at. For example, when you are looking at a big picture but your friend points at a small part of the picture for you to look at or when you look carefully at a butterfly in the park where there are many other things going on.

Occipital lobe: The occipital lobe is known for helping you see colours, shapes, things moving and many other things. For example, when you are in the playground, that part of the brain allows you to run around the playground without hitting into things and it also tells you how to fit into small places.

Temporal lobe: The temporal lobe helps in understanding words and also in helping you put words together to form sentences. You won’t be able to understand this sentence without the help of the temporal lobe!

Level 2 (10-14 years old)- How do we know the function of each part of the cerebrum?

The brain has been a mystery to researchers for a very very long time and so, when researchers found ways to learn about what the different parts of the cerebrum (the frontal lobe, parietal lobe, occipital lobe and temporal lobe) does , it was seen as a major breakthrough. You may be wondering ‘how do we know the function of each part of the brain (specifically the cerebrum)?’

In the early years, researchers had used neurophysiology (patients who already had damage to a part of the brain were tested to see which part of the body was affected). We shall focus on two lobes in the cerebrum today: the frontal lobe and occipital lobe.

Frontal lobe: Some of the functions that the frontal lobe is involved in includes problem-solving and also in our personality (factors and aspects that make you unique and different from others). In a very famous case study (an experiment that only focuses on one person) of a man named Phineas Gage, the researcher was able to learn that the frontal lobe is very important in controlling how you behave.

Before the accident, Phineas Gage worked on the train tracks with friends that said that he was very good at his work and can become a very important person in the company. However, after an accident where a long metal rod went through his head (specifically a part of the frontal lobe), his behaviour had changed overnight. Following the accident, he became very rude and swore a lot (which was something he did not do before the accident), he was also unable to stop himself when he wanted something and no longer wanted to reach a goal that he had given himself before the accident. His friends, who used to be close to him, said that he was ‘no longer Gage’ and that he has changed a lot. Thus, people now understand that the frontal lobe is responsible for behaviour. Now how about the occipital lobe?

Occipital lobe: The occipital lobe is mostly involved in helping us see. This includes the colours, shapes and movements that we see. One of the first research projects to better understand this part of the brain happened when Japanese went to war with Russia. A physician, Tatsuji Inouye, was sent to look at Japanese soldiers, who were injured during the war. The helmets worn by the soldiers were known as the brodie helmet and was not very good at protecting the whole brain and actually made the occipital lobe vulnerable. Moreover, the guns that the Russians used had smaller and faster bullets that allowed soldiers to survive even after being shot through the brain. This gave Inouye the perfect chance to connect the damage in the occipital lobe to the part of the soldier’s vision that was affected and so he created a grid. Here is an example (the drawing may not be accurate!)

Thus, researchers now know that the occipital lobe is involved in processing visual information (what we see) and that different parts of the occipital lobe processes different spaces in our vision.

However, one of the problems with using this kind of method to understand what different parts of the brain does is that there is usually more than one part of the brain that is damaged and so it is hard to identify which parts are actually needed for the specific role.

This problem was soon solved with the emergence of technology. There are other methods that are used to look at brains in healthy individuals when they are performing a specific task. So hopefully, there would be a lot more research in the brain to come!

Level 3 (15 years old and above)- Should the different parts of the brain really be seen as separate?

With the advancement of technology and machines to measure brain activity when performing certain tasks, more researchers notice that these brain areas are connected to one another with an activation (increase in activity) or deactivation (decrease in activity) in multiple brain areas when performing a specific function.

For example, in a study, the researchers wanted to examine the brain areas involved in attention when the number of items to focus on increases. The results showed that as the number of items to focus on increases, many parts of the parietal and frontal lobes also increase in activity. There were also other areas in the frontal and parietal lobe that maintained its high activity even when the number of items to focus on was low. Thus, it was suggested that the latter areas of the brain (that maintained high activity regardless of the number of items) may be involved in roles that are related to the task but are not specific to focusing on the different items in task (i.e it may be for reducing eye movements to help to focus rather than on keeping track of multiple items in the task).

Furthermore, there is also a network of brain areas that are also activated when we are not focused on what is going on in the outside world known as the ‘Default Mode Network’. The set of brain areas are involved when we are daydreaming and when our mind is wandering (this is a super hot topic of interest to researchers and us too!). The parts that researchers currently believe are involved in the Default Mode Network are parts of the parietal lobe, frontal lobe and limbic lobe (this part of the brain is mostly involved in forming emotions and learning). Thus, the general term used to describe brain areas that increase or decrease in activity when engaged in a certain function is the functional network.

In this present day and age, researchers are taking it even a step further by trying to create models of the brain by comparing its functions to that of computers. Thus, a buzzing area in the neuroscience (scientific study of the structure of the brain and the nervous system) community is neural networks. A neural network contains many interconnected neurons (basic units in the brain that receives information and passes on information that you can see in the picture below) which learns to match incoming and outgoing signals with each other. Following the learning process, it will then receive the information and produce signals based on the ‘knowledge accumulated’ during learning. Such research has not only interested neuroscientists (people that study neuroscience) but also computer scientists (people who study computers and how computer systems work). Thus, such emergent trends have better facilitated our understanding of how the brain works and we still have a long long way to go!

Parents Corner (Level 1)

Here is a quick story that you and your child can read to talk about which brain area is involved!

Sara had decided to play with a set of wooden blocks that her mother had bought. She remembered that her mother had placed the blocks in her cupboard and walked over to get them.

Which part of the brain helps Sara to walk?

After putting the blocks on the floor, she thought very hard about how she can build the tallest tower with a few blocks.

Which part of the brain helps Sara to think about this problem

(how to create the tallest tower with only a few blocks)?

Sara’s mummy saw her thinking very hard and sat next to her but because Sara was so focused on the blocks, that she did not greet her mummy.

Which part of the brain helps Sara to focus?

After thinking for a few minutes, Sara looked up at her mummy and saw that she was wearing a bright blue dress!

Which part of the brain helps Sara to see the dress colour?

‘You look like you’re thinking very hard,’ Sara’s mummy said. Sara nodded her head in agreement.

Which part of the brain do you think helps Sara understand what her mummy said?

References:

Broyd, S. J., Demanuele, C., Debener, S., Helps, S. K., James, C. J., & Sonuga-Barke, E. J. (2009). Default-mode brain dysfunction in mental disorders: a systematic review. Neuroscience & biobehavioral reviews, 33(3), 279-296.

Culham, J. C., Cavanagh, P., & Kanwisher, N. G. (2001). Attention response functions: characterizing brain areas using fMRI activation during parametric variations of attentional load. Neuron, 32(4), 737-745.

Damasio, H., Grabowski, T., Frank, R., Galaburda, A. M., & Damasio, A. R. (1994). The return of Phineas Gage: clues about the brain from the skull of a famous patient. Science, 264(5162), 1102-1105.

Ekhtiari, H., Nasseri, P., Yavari, F., Mokri, A., & Monterosso, J. (2016). Neuroscience of drug craving for addiction medicine: From circuits to therapies. In Progress in brain research (Vol. 223, pp. 115-141). Elsevier.

Glickstein, M. (1988). The discovery of the visual cortex. Scientific American, 259(3), 118-127.

Harlow, J. M. (1848). Passage of an iron rod through the head. The Boston Medical and Surgical Journal (1828-1851), 39(20), 0_1.

Leff, A. P. (2015). Tatsuji Inouye (1881–1976). Journal of neurology, 262(10), 2399-2400.

Zelenska, M. (2019) Neural Networks-Relation to Human Brain and Cognition. Medium. Retrieved July 26, 2020, fromhttps://becominghuman.ai/neural-networks-relation-to-human-brain-and-cognition-b45575359f64