Animal vs Human Brain - Zeynep Ölmez '24

There are many people who think that humans have evolved from animals such as chimpanzees. Their reasoning for this is actually comparing their abilities to humans which seem similar. In reality although there are major differences, the cognitive side of the brain is quite similar. It could be said that there is no fundamental distinction between the mental capacities of a man and those of some animals. Some observations have shown that animals have demonstrated human-like skills. Some examples of it are teaching, their short-term memory, and planning. It is detected that some animals can actually teach. Mostly, they are parents who try to make their children learn how to survive, like cats teaching their kittens how to kill and find food, by demonstrating it to them. And similarly, humans teach their kids everything about life, like how to walk and talk. It should be added that not all animals teach but even if some do it, it shows a similarity between the human and animal brain. The short-term memory of chimpanzees is just somewhat inferior than that of humans. Only five to seven things are retained in memory for both species. This doesn’t mean chimpanzees are as smart as humans because the ‘five things’ that we can remember differentiates between the two species. While humans can remember five full stories, the chimpanzees can only remember the name of the five stories. So human brain works more complex and it can achieve more in a sense. This means that based on the additional cognitive services of the species, same constraints in different species may have radically different effects. Lastly, planning was considered to be unique to humans till now, but recent experiments made us doubt this belief. This experiment was made with scrub jays, and people observes that these birds portioned their food for the whole day depending on how much they had. In comparison to humans this is basic planning, humans also think ahead, but there are more complicated actions involved in the planning process. So while animals might have easier and more straightforward plans, it is still a closer step to the way the human brain works. Besides the cognitive side of the brain, other similarities were found between human and animal brain’s as well. Peter Cook made a research based on 2 types of animals and their relation to humans. Cook's research centered on three areas: neurobehavioral evaluations of wild sea lions, opportunistic dead brain network imaging in dogs and other animals, and functional brain imaging in dogs. His study on sea lions provided information about the parallel between humans and sea lions in the hippocampus. A sophisticated brain structure, located deep within the temporal lobe is the hippocampus. It plays a significant part in memory and learning which creates the similarity between the sea lion and human. The research also showed that people and sea lions had similar reactions when affected by hippocampal epilepsy. Cook discovered that dogs have a significant level of neurological skill for social processing similar to humans, as a result of his studies on dogs. Most of the dogs interactions with humans seem to make them happy and it is also proven that the difference between different humans and different canine faces can be told apart by them. Also they are interested in how people and dogs interact. As a result, it is possible to use dogs as an animal model to study social neuroscience. In addition, Cook discovered that dead brains could be gathered and trained canines could be trained to store enough information for functional brain imaging, adding another way to compare how the brain has developed and evolved.

One of our bodies' most interesting parts, the brain is where all of our behaviors, feelings, and instincts originate. The brain serves as the coordination hub for sensation and action and aids in the seamless operation of all the body's systems and organs. It is made up of billions of neurons that collaborate to receive and transmit information. This body part is unique for all, including animals. Different species have different brain structures. For example, the brains of certain spiders make up a significant portion of their body, which is unusually enormous for their size. Spider brains may also take on some extremely intriguing forms, pouring out into the spider's body chambers and legs in addition to its head. For spiders to carry out tasks like web-building or hunting, their enormous brains are crucial. Another example is squids. The squid's brain is formed like an oval with a hole at the center of it, which makes it incredibly efficient at connecting information between its two huge eyes. From this comparison we can conclude that the purpose of the animal, defines its brain structure. Independently of the impacts of body weight and evolutionary history, species variations in lifestyle, particularly nutritional preferences and patterns of juvenile growth, are linked to diversity in brain weight. These findings start to hint at the evolutionary forces favoring various brain sizes and brain components when combined with behavioral and neuroanatomical assessments. The similarities between the brains of various mammals may easily be seen when they are put side by side. The same components are present in all brains, despite the fact that their sizes and fold patterns vary greatly. Even if the components are the same, this does not imply that the same number of each type of cell is used to construct brains of the same size. Furthermore, it is not necessarily true that a larger brain contains more cells than a smaller brain. Most scientists believed that brains of the same size would have the same amount of neurons, until around ten years ago. They believed that there was a single ‘way’ used by nature to create brains and that this was the same for all brains. Additionally, it implied that the brain would have more neurons the larger it was. However, these hypotheses were both wrong. In 2005, a study was conducted to find a way to count the neurons present in the brain. Turning a recently dead brain into liquid form, was founded to be the most effective way, because not every part of the brain has equal amount of neurons, so it is not possible to count the neurons in a section of the brain, and estimate a number according to that. This technique was used for rodents and primates. Although rodent had the bigger brain size between the two, primate had more neurons than the rodent. As a conclusion scientists found out that every brain has different building rules. These rules show the relation between the size and the neurons and their proportionality. So scientists have figured out a pattern between these characteristics of the brain and the structure of the brain, and although they don’t surely know the answer to why that is, they believe that the complexity of the brain affects the animals actions and emotions.

When the anatomy of a human brain is explained, there are many parts to it. First of all the brain is made of 3 necessary parts. The cerebrum taking up most of the space, consist of the left and the right hemispheres. It controls most of the human skills such as; understanding speech, thinking, emotions, learning, touch, vision, and hearing, as well as speaking, learning, and fine motor control. Then there is the cerebellum, right under the cerebrum, and it helps us synchronize your muscular movements, our posture, and balance. Lastly, the brainstem which connects the spinal cord to the cerebrum and cerebellum. Numerous automatic processes are carried out by it, including those related to breathing, heart rate, waking and sleep cycles, digestion, etc. and swallowing. When you get deeper into the brain, like it was said before, there is the left and the right side of the brain. A group of fibers known as the corpus callosum connects them and carries messages from one side to the other. The opposing side of the body is controlled by each hemisphere. The left hemisphere of the brain is generally in charge of speaking, understanding, mathematics, and writing. Creativity, spatial awareness, creative ability, and musical talent are all governed by the right hemisphere. The cerebrum also have lobes known as; frontal lobe, motor strip, broca’s area, sensory strip, parietal lobe, Wernicke’s area, temporal lobe and occipital lobe. The frontal lobe contorls the humans personality, which means their emotions and behavior. It also includes our problem solving skills and judgment as well. The Broca’s area is inside the frontal lobe and it affects our speech abilities. Similarly, the motor strip is responsible for our body movements and it is also included in the frontal lobe. The parietal lobe interprets language, signals from vision, hearing and our memory. Plus, it also consists the sensory strip which affects the way we feel pain and our sense of touch. The occipitial lobe contols our vision and its characteristics such as color, light and movement. The temporal lobe is responsible for hearing and memory, and the Wernicke’s area is a part of this lobe which understands language. This complex structure of the brain consists of everything that makes us a human and differentiates us from animals and their brains.

Animal brains occur in a wide range of sizes and forms, but intelligence is not strongly correlated with brain size. The number of neurons and their location appear to be more important than brain size. More than any other animal, humans have more neurons than any other species in their cerebral cortex, the part of the brain responsible for language, thinking, and information processing. This might explain why we have improved cognitive capacities. To find similar neuron-dense brain regions and their roles in brain function, scientists are examining different species. Numerous insects provide as examples of how highly varied motor repertoires, vast social systems, and cognition may exist with extremely little brains, highlighting the necessity to comprehend neural circuits. The numerosity, attentiveness, and categorization-like functions observed in insects may only need relatively few neurons, according to neural network analysis. Because of fundamental biophysical limitations, bigger neurons are required in large animals, which results in larger brains, at least in part. Additionally, they have more neural circuit replication, which improves the intricacy and precision of perception, allows for more parallel processing, and increases store capacity. In other animals such as bees, their learning abilities have developed very impressively. They must be adapted to a lifestyle where they need search really long distances to find a suitable feeder, and then memorize the place of the feeder, and how rewarding the feeder is depending of the time of the day. Their memorizing and learning abilities are really stong which means that their frontal and temporal lobe has more neurons present than the other parts of their brain. Another example of this is insects with big eyes such as bigger flies. Their eyes are bigger than humans meaning they have greater vision abilities. This shows us that their occipital lobe has more neurons than humans which gives them this specific ability. Therefore, while certain increases in brain volume will have an impact on cognitive ability, numerous increases in specific brain regions, particularly those related to sensory and motor processing, only result in quantitative gains: more accuracy, sensitivity, finer resolution, and more detail.

To give a specific example of differences between the human and animal brain, the sheep and human brain can be compared. As for the size of their brains, human brain is larger. The shape of the sheep brain is also different meaning that, the complex structure of the human brain isn’t present in sheeps and their brains do not have as many turns (the shape where the brain looks like it has turns all around it) and it is much simpler, with less turns and a smoother surface, which results in the smaller brain size. In contrast to the spherical form of the human brain, the brain of a sheep is elongated. Given that the backbone of a person is vertical, as opposed to a sheep's horizontal backbone and its brain's

outward orientation, the human brain stem is oriented downhill and towards the backbone. The size of the cerebellum is also different for the sheeps and human. Humans have more sophisticated tough behaviors, greater motor skills and learning capacities, which means their cerebellum is larger. The sheep is the quite opposite of humans but some of their their senses such as smell is more developed since they rely more on it. These characteristics shows that the olfactory bulb in the sheep's brain is noticeably larger. Also, the location of the human hind brain is likewise different from that of sheep due to the human's upright posture. The human brain enables invention, creativity, and imagination. This is a key distinction between the human and animal brains, as evidenced by the size of the prefrontal cortex (In humans it is larger).

In conclusion, although there are some similarities between the human and some of the animal brain, humans are more complex creatures and most of their abilities have developed better in time, which means that they have more neurons on most the the lobes of the brain compared to animals. The said to be lobes are also explained and it could be said that even the main parts of the brain have its own parts and those parts also get divided into other parts. Also depending on the animal, they have different characteristics due to the amount of neurons on a part of their brain. The brain size doesn’t show the intelligence of a creature. Intelligence cannot directly be measured, since different species have different areas that they are better at. As an example, bees and insects were given. Lastly a more concrete comparison was made between sheep and human brain regarding the size and the shapes of the brain. And it was found that both of them had different specialities and that the human brain was larger with more neurons due to the shape of the brain.

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