The brain is the command center of your body. Thousands of signals from the outside are reaching it every second, and based on these signals it determines a course of action and issues commands which are then carried out by other parts of the body.
Much of this happens on the subconscious level, but the brain also carries out activities of which you are conscious. This means that you have a choice and need to make a decision on what to do next.
What separates the mammals from other types of animals such as reptiles, amphabians or fish, is the fact that they have an enlarged part of the brain called the cerebrum.
Your Monkey Brain
One group of mammals has a cerebrum that is much larger than the other groups. These are the primates, a group that includes monkeys, apes such as our close cousins the chimpanzees, but also humans.
This allows them to do much more than just work based on instinct. If you have ever watched a documentary on wolves, then you have seen that they can make pack strategies, for example when hunting.
Monkeys are even more sophisticated than that. They have most of the basic wiring that humans have. Monkeys have shown the ability to come up with complex strategies and also to make rational choices.
Smart Chimp: “I am completely ignoring your BS!“
The cerebrum is located at the top of the head and is the biggest part of your (or a monkey’s) brain. It is separated into two hemispheres, a right and a left one.
The right hemisphere is said to be tied more to creativity, while the left hemisphere is more tied to logic. Also in an interesting twist, the right hemisphere controls the left side of your body and the left hemisphere the right side.
The two hemispheres are tied together by a bundle of neural fibers called the corpus callosum. It facilitates communication between the two sides of the brain.
The top of the cerebrum is covered by what is called the cerebral cortex. This is a thin layer of grey-matter, which is densely packed with neurons. Much of the thinking that your brain does happens here.
What helps the cortex to pack so much thinking power is the fact that it is made up of many ridges. These ridges divide up the cortex into many parts and each one is responsible for different functions within the brain.
The cerebrum itself is divided into four lobes: the frontal lobe, the parietal lobe, the occipital lobe, and the temporal lobe. This is where the action takes place.
If you see a bunch of lights flying fast at night, you might interpret them as being UFOs coming to Earth from another solar system. The activity you just performed is called reasoning.
You get some sort of an input from the outside and your brain tries to make sense of it based on some internal rules that it has.
Whether it is whack or logical, this type of action takes place in the frontal lobe. This part of the brain is the seat of weird conspiracy theories, but also of critical thinking.
Take the classical example of deductive reasoning:
“All men are mortal.”
“Socrates is a man.”
“Therefore Socrates is mortal.“
You arrived at a conclusion based on logic.
In the frontal lobe, you can come up with ground-breaking theories of quantum physics, but also theories of a Grey and Reptilian alien-conglomerate controlling all the politicians of this planet. The mental steps that take you from a basic assumption to a solution happen here.
At the moment what you are doing is reading. Your eyes are scanning the screen, looking at the letters, combining them into words and sentences and giving meaning to them. This ability is thanks to the processes happening in the parietal lobe.
This lobe processes visual information and the act of reading is basically looking at symbols in front of you, taking them in, creating patterns between them and based on these patterns interpreting what it sees in front of its eyes.
Basically, these patterns (words being strings of symbols called letters) create thoughts in your brain which then helps you process information.
It works in a similar way with interpreting mathematical symbols and helping you count. This lobe is also involved in basic arithmetic and calculations. On a more abstract level, drawing is also governed by the parietal lobe.
It also lets you perceive depth. What happens is that the lobe helps your brain build a 3-D plane of the outside world and so helps you understand all the spacing around you. This is very important if you want to orient yourself and also manipulate objects.
Processing visual signals and interpreting them as meaning is just one of the things the parietal lobe does. It also interprets other senses and lets you understand what is happening in the world around you.
For example, through your sense of touch, you can feel that it is cold outside. This type of knowledge about the outside world happens in the parietal lobe.
The parietal lobe is involved in the processing of different sensory information from the outside, things like touch and pain, temperature, as well the intensity of each.
Look around you. What do you see? You probably see different things and different colors. The fact that you can “see” and know what you see is due to actions performed in the occipital lobe.
What this lobe does is to take signals coming from the eyes in the form of visual images, and then connects them to things you have stored in your memory, thereby helping you interpret what is happening.
It also works together with all the other lobes and different parts of the brain in a number of things, for example with the parietal lobe, it helps you in reading comprehension (so the fact that you can understand what you are reading right now is due to the action of these two lobes).
Since it is located in the back of the brain, it is also connected to the cerebellum. Due to its importance, the entire back of the head area is well protected by the thick bones of the skull.
You are sitting in a chair in your room, when suddenly your dad yells for you to get him a beer. “Fuck off!” you think to yourself.
The fact that you are able to do that is thanks to the temporal lobe. It allows you to process auditory signals and interpret their meaning. So when someone is talking to you, your temporal lobe is hard at work.
Have you ever walked through a field and smelled shit? Well, you have this ability thanks to the temporal lobe. The temporal lobe takes in signals captured through your nose and the sense of smell, and then interprets them.
This lobe is also very important for your memory, although the lobes on each side of the brain store a bit different types of memory.
The left side stores the verbal memory, so things like individual words, the names of people and places, while the right side stores visual memory, things like pictures, faces, and other visual images.
Basically if you have a friend named John, the memory of his face is stored in your right parietal lobe, while the memory of his name is stored in the left parietal lobe.
Since now you know which side stores which type of memory, do you now understand why some the right-side (creative) vs. left-side (logical) of the brain stereotypes arose?
Your Human Brain
If monkeys have most of the basic wiring in the brain that humans have, what separates you from them? It’s a matter of size. Human brains are much larger than even the chimp brains.
A study notes that the human brain is three times bigger than the brain of a chimp:
“The human brain is about three times as big as the brain of our closest living relative, the chimpanzee. Moreover, a part of the brain called the cerebral cortex – which plays a key role in memory, attention, awareness and thought – contains twice as many cells in humans as the same region in chimpanzees. Networks of brain cells in the cerebral cortex also behave differently in the two species.“
But why did this difference in size arise?
Ferris Jabr in his article writes that there was a trade-off between energy being channelled to the brain and energy being channelled to the muscles. So chimps have relatively bigger muscles, while humans have relatively bigger brains.
At some point during the evolutionary process, humans started putting less of their nutrients towards their muscles and more into their brains:
“In other words, there was a strong evolutionary pressure to modify the human regulatory regions in a way that sapped energy from muscle and channeled it to the brain.“
A human brain uses 20% of the energy of the body at rest, while a chimp brain uses only 10%. This means that huge amounts of carbohydrates (as well as other nutrients) need to be channelled into the brain very often.
This could have arisen from a mutation in glucose-transporting genes:
“In humans, but not in chimps, the regulatory sequences for the muscle and brain-focused glucose-transporting genes had accumulated more mutations than would be expected by chance alone.“
These simple mutations that allowed more glucose to be transported to the brain could have allowed it to do more work and get bigger and bigger.
These type of changes could have in turn led to even more changes happening in human brains and allowed our distant ancestors to start doing things that their cousins the chimps couldn’t do, like talk.
Two of the most important parts of the brain when it comes to languages are Broca’s area and Wernicke’s area. Until recently, it was thought that chimps did not have these areas, but recent research has shown that they do in fact have them, but they are just wired a bit differently.
In fact, Broca’s area in the human brain has changed much more in comparison to the chimps than the rest of the brain:
“Broca’s area has also swelled disproportionately during our species’ evolution. Human brains are 3.6 times larger than those of chimpanzees, on average. Yet Broca’s area is more than 6 times larger in humans than chimpanzees, notes Natalie Schenker, a neuroscientist now at the University of California, San Diego, who led the study along with Sherwood.“
The biggest difference between human and chimp brains is in the frontal part of the brain. It is much bigger in humans:
“Where we depart from our animal brethren is in the great development of the front part of our cerebral cortex, the frontal lobes, and the greater proportion of cerebral tissue, called association areas, which integrate the information obtained from the regions that directly receive sensory information. These latter regions are called the primary sensory and motor areas because they receive simple, pure sensations and direct the movement of the body. It is within the frontal lobes that we humans mull over the past, prepare for the future, and reflect on its implications.“
The connections between the neurons there are much tighter. This is also the part of the brain that is involved in reasoning. Since the neuron connections are much tighter, higher thought could arise.
However there are some disadvantages as well. Chimps are probably much less likely to fall for things like the Einstellung effect and thereby it is much easier for them to be first principles thinkers and disregard the bad ways of coming up with solutions of others.
As Laurie Santos states in her interview:
“If you show chimpanzees a case where somebody is solving a puzzle box in a very inefficient way, they have some mechanism to completely ignore that and solve it on their own. If you show a four-year-old child a case where somebody is solving a puzzle box in an inefficient way, they cannot override the information that they got. The extent to which they use that automatically is so built-in that it’s going to not just make the child solve the problem the wrong way, it’s going to make them unable to reason about the causal structure of that task in future cases. This is remarkable.“
Tiny changes in gene mutations led to changes in how the brain functions in humans, which led to huge changes for human behavior.
Dr. Brainiac: “So you see Mr. Chimp, there are some things that make human brains special.“
Smart Chimp: “I have four words for you: Planet of the Apes – it’s a documentary.“
But as we all know from the historically accurate “Planet of the Apes” movies, apes are still going to rule us.
You can use mnemonics to remember the parts of the brain and its functions.
Remember this way of remembering things is effective due to the way that your limbic system works and stores memories.
Joshua Foer (author of “Moonwalking with Einsten” and a guy who taught himself ancient memory techniques in order to become an American memory champion) suggested to invent outrageous images to help you better remember what you are trying to remember. For example if you want to remember what the brain stem does:
Drunk Fonzie wobbling through a dark alleyway, stumbling down and vomiting, and then falling asleep on the corner. Bernie Maddoff being the middleman for a Ponzi Scheme.
What other things about the brain do you want to know?
If you haven’t already, go back to read Part 1 on the human brain.