Neuroanatomy — Brain Lobes
It’s 5 in the morning, and you wake up, millions of neurons sending electrical signals to the different parts of your body, and each other, as you get out of bed.
As you move towards the sink, different parts of your brain light up, working relentlessly to make sure you can keep your balance, your limbs move in a certain way, and that you can reach your destination in a short amount of time avoiding possible obstacles in your path.
Every second of the day, our brain is constantly sending signals across networks of neurons to make sure we can function properly.
Across a whopping 7 million years, human brains have tripled in size, though most of the growth occurred in the last 2 million years.
During this time, starting from the brain stem and cerebellum, also known as the ‘old brain’, we have grown complex neural connections throughout our brains, creating networks of neurons capable of governing our emotions, movements, memories, and much, much more.
Starting with simple, involuntary actions such as heart palpitations, balance, and coordination, we have evolved to be able to feel and think of more things that any animal on Earth ever has, to our knowledge.
Over time, different parts of our brain, known as lobes, started to develop more, and as these parts grew, so did human intelligence. As our brains developed in the front, we were able to think, retain and make memories, and feel emotions, and as it developed on the sides, we were able to talk, and effectively communicate with one another.
Where do the neural networks controlling our variety of actions take place?
What are the Brain Lobes?
In our brains, we have 2 hemispheres, a right and left side of the brain. Each side contains 4 lobes, localized areas responsible for certain actions that we carry out every day.
The Frontal Lobe, Parietal Lobe, Temporal Lobe, and Occipital Lobe are all responsible for governing different parts of our actions, with varying levels of complexity. While each lobe may be a localized part of our brains, to carry out our daily activities, the different lobes constantly work with each other to do so.
Going back to the previous analogy, while walking towards the sink, your occipital lobe would process the visual information, while your frontal lobe would process the information on what steps you should take to reach the sink, as well as what you will do upon reaching.
The parietal lobe, responsible for spatial relationships would help you avoid any obstacles, avoiding that nasty bruise on your toe after bumping into the door frame.
Let’s take a closer look at each lobe!
1. The Occipital Lobe
The occipital lobe is the visual processing center of the brain. It receives information from the eyes, through optic nerves. The lobe is divided into different sections known as cortices, and the primary cortex in the Occipital lobe is known as Visual One(V1), or Brodmann Area 17. This part of the lobe is where basic info about colour and motion is processed and responds best to lines and edges in a particular orientation.
V2 and V4 are responsible for colour and orientation, while V5 is responsible for motion and primarily receives information from V1. In has the highest neuron density in the brain, just above the somatosensory cortex, located in the parietal lobe!
2. The Temporal Lobe
The temporal lobe, also known as the neocortex, is involved in auditory perception, such as hearing, and similar to the Occipital Lobe, it contains the primary auditory cortex. The primary auditory cortex receives sensory information from the ears and secondary areas, or cortices, process this information into meaningful parts such as speech and words which we use in everyday life.
It is the second-largest lobe in the brain, taking up 17% of the cerebral cortex in humans, and only primates have this segment of the brain!
3. The Parietal Lobe
It processes sensory information regarding the location of body parts as well as interpreting visual information, and processing language and mathematics.
The parietal lobe has 2 main functions. The first involves sensation and perception and the second integrates sensory input, working closely with the Occipital Lobe.
It first integrates sensory information to form a single perception, known as cognition. The parietal lobe then constructs an accurate spatial ‘coordinate’ system of our surroundings and environment.
This allows us to understand the depth of our surroundings. When you’re able to avoid bumping into someone, it is because you have an accurate perception of where they are concerning you.
This part of the brain also includes the somatosensory cortex, the primary center for sensory input to be processed, with the second-highest neuron density in the brain!
4. The Frontal Lobe
The frontal lobe is the most complex, as well as the largest part of the brain that controls important cognitive skills in humans, such as emotional expression, problem-solving, memory, language, judgment, etc.
These activities are known as ‘higher functions’ and are also a key reason as to why humans are so unique, and different from other organisms. The frontal lobe in human brains is extremely complex and developed, accounting for 2/3 of the entire brain!
The frontal lobe also contains the Primary Motor Cortex, essential to our refined and precise movements. The motor cortices in general, including the primary motor cortex, were found to have the least neuron density, due to the simplicity of their functions.
When we talk about Iq, we are often referring to the Frontal Lobe. With the highest number of cortical neurons, some of the most complex and efficient networks can be found there, which affect our intelligence. Iq tests aim to determine the complexity of our networks based on how we solve problems and give a score representing your intelligence based on this.
In essence, the frontal lobe is the “control panel” of our personality and our communication abilities. While the other lobes of the brain are there to help us survive and function properly, the frontal lobe is what makes each human so distinct from the others.
Key Takeaways
- The human brain can be divided up into 4 different parts, known as lobes: Frontal, Parietal, Temporal, and Occipital
- Each lobe is a localized area that performs, processes, and governs certain information and actions.
- The Occipital Lobe primarily deals with processing visual data, which is received from the eyes through optic nerves. It is composed of various visual cortices and each deals with a different part of our vision.
- V1, the primary visual cortex is where basic info about colour and motion is processed and responds best to lines and edges in a particular orientation. V2 and V4 are responsible for colour and orientation, while V5 is responsible for motion and primarily receives information from V1.
- The Temporal Lobe is involved in auditory perception. It contains the primary auditory cortex, responsible for receiving sensory information from the ears, while secondary areas, or cortices, process this information into meaningful parts such as speech and words.
- The Parietal Lobe processes sensory information regarding the location of body parts as well as interpreting visual information, and processing language and mathematics. It involves sensation and perception and integrates sensory input. The parietal lobe constructs an accurate spatial ‘coordinate’ system of our surroundings and environment, allowing us to perceive the depth of our surroundings. It is also home to the Somatosensory Corex.
- The Frontal Lobe deals with higher functions such as emotional expression, problem-solving, memory, language, judgment, etc. It also contains the Primary Motor Cortex, essential to our refined and precise movements. When we talk about Iq, we are often referring to the Frontal Lobe. With the highest number of cortical neurons, some of the most complex and efficient networks can be found there, which affect our intelligence, which is what Iq tests measure.
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