Structure and function of the brain part 1 — the five lobes of the brain

The quick brown fox jumped over the lazy dog.

Okay, you just read that sentence. Awesome — you can read!

Now, what would happen if you read it out loud?

Probably the same thing, you would just understand that the quick brown fox jumped over the lazy dog.

Now read it while standing on one foot.
Now read it in a freezing cold shower.
Now read it while watching the part in the titanic where rose leaves jack to die.
Probably at this point, you have read “the quick brown fox jumped over the lazy dog” more than five times, and kudos to you if you are still here.

And I get it. You are probably like so what. The fox can jump, the dog is lazy. I don’t care. I read it five times and nothing changed

But that’s where you are wrong.

See every time you read the sentence whether it be out loud, in your head, on a bike, in the shower, standing on one foot, etc. Different parts of your brain were activated.

There are seventeen main parts to the brain but before we go through all of them, we need to cover the five main lobes: frontal, parietal, temporal, occipital, and cerebellum (not really a lobe but equally as important). The other twelve are covered in another article.

FRONTAL LOBE:

The frontal lobe is located directly behind the forehead (hence the name frontal lobe). It is important for voluntary function, expressive function, and higher executive function. For example, speech and language procession is processed in Broca’s area (a region in the frontal lobe which will be covered in the next article). It houses the primary motor cortex which coordinates primary movements (ex. walking). It helps with empathy so understanding the feelings and sentiments of others.

PARIETAL LOBE:

When you think about the parietal lobe, I want you to think of sensory input. It is located in the upper back portion of the skull and can be divided into two sections: one that involves sensation and perception and the other that is concerned with the integration of sensory input. The first function, “integrates sensory information to form a single perception (cognition). The second function constructs a spatial coordinate system to represent the world around us” [neuroskills]. Sensations that the parietal lobe processes include: touch, heat, pain, pressure, cold, etc. So remember that cold shower you had while reading the quick brown fox jumped over the lazy dog. Yeah, you can thank your parietal lobe for the shivers you had after.

TEMPORAL LOBE:

The temporal lobe is located behind the ears and sits above the brainstem and cerebellum. Whenever you process and encode a memory or listen to information, that’s the temporal lobe. The temporal lobe also plays a very important role in “processing emotions, language, and certain aspects of visual perception” [Queensland health]. The temporal lobe receives different auditory frequencies and processes them into meaning (so basically language). A very important function involved with this is selective hearing. And no I don’t mean when you pretend not to hear your mom when she tells you to clean your room. The frontal lobe filters out unnecessary frequencies so you can focus on interpreting the important sounds emitting from your environment. Furthermore, another important function of the temporal lobe is face and emotion perception. Like when someone is crying and you think, I should probably see what’s wrong, they seem sad.

OCCIPITAL LOBE:

The occipital lobe is located at the back of the skull — behind the temporal and parietal lobes. It is typically associated with processing visual information. The occipital lobe contains 5 main sections but we aren’t going in-depth in them today. But here’s a list: the lingula (takes general information of the field of vision from the retina). The primary visual cortex (receives information from the retina and processes it). The secondary visual cortex (receives information from the primary visual cortex). The ventral stream (primary stream the visual cortex uses to send information to the temporal lobe which interprets it into meaning). Finally, the dorsal stream (the other stream the visual cortex uses). Long story short, they all aid in visual comprehension (i.e. distance, depth perception, colour, movement, facial recognition, etc.). Basically, thank your occipital lobe for your vision

CEREBELLUM

The cerebellum is located at the very back of the brain. Its function is to coordinate voluntary movement to maintain posture balance and equilibrium. The cerebellum isn’t technically a lobe or even part of the cerebrum, but it’s a major part of the brain so I decided to include it anyway. The cerebellum receives information from other parts of the brain such as the brainstem and spinal cord; this information is then used to control voluntary movements. Researchers believe that the cerebellum plays a role in thinking, but this is just a hypothesis at the moment. Finally, motor learning is a fundamental function of the cerebellum. Whenever you learn something new such as playing an instrument or playing a sport you often go through a trial and error process until you have found the proper way to do the action. The cerebellum plays a critical role in this process

CENTRAL SULCUS:

Okay okay, this isn’t a lobe. You caught me. But the central sulcus is very important for visualization of the different parts of the brain, so I’m including it anyway! The central sulcus (or central fissure) runs down the middle of the brain separating the parietal lobe from the frontal lobe.

Okay, let’s go back to the quick brown fox that jumped over the lazy dog. Remember all that crazy stuff I asked you to do while reading, let’s go through which lobes they activate.

1. Just reading: the temporal lobe and occipital lobe
2. Reading out loud: temporal lobe and occipital lobe too but this time processing visual and auditory information
3. Reading while standing on one foot: temporal lobe, occipital lobe, and cerebellum
4. Reading while standing in a cold shower: temporal lobe, occipital lobe, and parietal lobe
5. Reading while watching the sad part of the titanic: temporal lobe, occipital lobe, and frontal lobe

There you have it. The five main lobes of the brain (plus the central sulcus)

TL;DR

• Frontal lobe → movement
• Parietal lobe → sensory input
• Temporal lobe → hearing
• Occipital lobe → seeing
• Cerebellum → coordination
• Central sulcus → visual separation of the brain