This article will answer the question of how the brain controls human behaviour. It will discuss every part of the brain and its functions in the human body, along with some frequently asked questions about the same.
How Does the Brain Control Human Behaviour?
Our behaviours result from an interaction between our genetic factors, brain chemistry, brain functioning, and our economic, social, and psychological environments.
However, when speaking of how exactly the brain controls human behaviours, we need to understand that the brain is composed of complex brain parts, each of them assigned several functions to control the human body. We will consider each of the following below.
The Brain Stem
The innermost region of the brain is called the brain stem. This is also the oldest part of the brain. The medulla, the area of the brainstem that controls breathing and heart rate
The role of the brain stem is to control basic functions like motor response, breathing and basic attention. It begins where the spinal cord enters the skull and forms the medulla.
The medulla is the area of the brainstem that controls breathing and heart rate. Many times the medulla is enough to sustain life. In animals that have parts of the brain severed they are still able to move, eat and breathe.
The structure of the brainstem that helps control several movements such as balance and walking is a spherical shape right above the medulla and is called the pons.
Reticular Formation
A long narrow network of neurons known as reticular formation runs through the medulla and pons. This plays an important role in eating, walking, sleeping and sexual activity.
The primary role of reticular formation is to filter out stimuli that join the brain to the spinal cord and also relay the various remainder signals to different other parts of the brain.
If this is severed in animals from higher brain regions, the animals fall into a deep state of coma. Electrical stimulation applied to this area, causes animals to become instantly awake.
The Limbic System
The Limbic system is another part of the brain that helps in processing emotions and behaviour. The thalamus is an egg-shaped part above the brainstem and helps filter sensory information from the spinal cord and it passes through the reticular formation. They also help in relaying signals to higher regions of the brain (Sherman & Guillery, 2006).
The thalamus shuts off various incoming signals from the senses and allows us to rest. Hence, it plays a significant role in sleep. The thalamus receives important signals from several higher brain regions and forwards them to the cerebellum and medulla.
The cerebellum
The cerebellum is also known as the little brain and consists of two wrinkled ovals which are located behind the brain stem. The function of the cerebellum is to coordinate movement which is voluntary. Damage to this region leads to dis-regulation in walking, balance and holding hands steadily.
The cerebellum helps in distinguishing between various sounds, and helps in learning and regulating emotional responses. (Bower & Parsons, 2003). Alcohol consumption influences the cerebellum, hence it is difficult to coordinate movements, under the influence of alcohol.
The limbic system consists of the amygdala, the hypothalamus, and the hippocampus. It is largely responsible for memory and emotions. It is located between two cerebellar hemispheres and the brain stem.
The Amygdala
The amygdala is primarily responsible for the regulation of fear, aggression and perception. It consists of two almond-shaped clusters. It is connected to other bodily functions such as facial expression, and the sympathetic nervous system, which is important in regulating fear response.
It is also responsible for the release of neurotransmitters which is related to processing aggression and fear, as well as processing smell (Best, 2009).
Amygdala once electrically stimulated influences aggression. In an early study, Klüver and Bucy (1939), found that damage to the amygdala leads to an angry animal becoming passive and less responsive to aggressive behaviour and fearful situations.
Research shows that any experience from dangerous situations stimulates the amygdala which helps us learn from situations, remember the information, and avoid the situation in the future. (Sigurdsson, Doyère, Cain, & LeDoux, 2007).
The Hypothalamus
The hypothalamus is located right under the thalamus. This part of the brain helps perform a variety of functions such as regulation of the endocrine system through the pituitary gland.
This structure helps in performing a variety of functions such as regulation of sexual behaviour as well as hunger. It also helps in regulating body temperature, and thirst and is responsible for responding to the satisfaction of needs and creating feelings of pleasure.
The Hippocampus
The hippocampus plays a crucial role in storing information in the long- term memory. It has two “horns” and curves back from the amygdala. If the hippocampus is damaged a person cannot build new memories. The person might not be able to build new memories, however, the older memories before the damage might remain untouched.
The Cerebral Cortex
The cerebral cortex is responsible for thinking and consciousness. Humans have a larger cerebral cortex compared to others. The cerebral cortex is the outer brake-like layer of the brain and allows individuals to use complex skills, live in social settings, use language as well as create tools (Gibson, 2002).
Corticalization is known as the folding of the cerebral cortex. Compared to other animals, humans have a wrinkled and folded cerebral cortex, this creates a greater size and surface area, which allows for enhanced learning, thinking and remembering.
Each hemisphere of the cerebral cortex is divided into two hemispheres and subdivided into four lobes, each of them is separated by folds known as fissures.
The frontal lobe is responsible for memory, thinking, judgement, and planning, this starts from the front of the brain and moves over the top in the cortex.
The parietal lobe follows the frontal lobe, this part of the brain extends from the midsection of the skull. This is primarily responsible for processing information about sensations such as touch.
At the back of the skull comes the occipital lobe, which is responsible for processing visual information. The temporal lobe is located right in front of the occipital lobe, this section of the brain is responsible for language and hearing.
Understanding functions of the Cortex
In a study done by Gustav Fritsch and Eduard Hitzig, they found that by applying electric stimulation to several parts of a dog’s cortex, several parts of the dog’s body could be set into motion.
A significant discovery was made regarding the principle of the brain’s activity. In this study, it was discovered that stimulating the right side could produce movement in the other side, the left side of the brain, and the same could be seen by applying the principle on the other side, the right side of the brain.
This principle is called contralateral control, which tells us that the brain is wired in a way that the left hemisphere of the brain receives signals from the right side and controls the body. The same principle is applied to the other hemisphere of the brain.
The motor cortex was discovered by Gustav Fritsch and Eduard Hitzig (2009). This part of the brain controls and executes the movement of the body. This is possible by signalling the spinal cord to the cerebellum.
Providing mild electric stimulation to several areas of the motor cortex, researchers have been able to map several areas of the motor cortex, by observing the body movements of fully conscious patients. They have found these patients feel no pain as there are no sensory receptors in the brain.
The somatosensory cortex is the area that is located behind the motor cortex. Just like the motor cortex, the somatosensory cortex of the brain sends several signals to specific areas of the body. The motor cortex and the sensory cortex, relatively occupy a small area of the brain.
The somatosensory cortex is that area of the brain that receives information from different parts of the sensory receptors of the skin and controls movements of several parts of the body, this is located parallel to the motor cortex, behind the frontal lobe.
If the body region is more sensitive, the more space it occupies for its function in the sensory cortex. Areas such as our fingers, genitals and lips occupy a significant amount of area in the sensory cortex.
Several other areas of the cortex process different other types of sensory information. For example, the visual information is stored in the visual cortex, which is located in the occipital lobe. This area is located at the back of the brain. If this area of the brain is stimulated, one can see several colours as well as flashes of light.
The temporal lobe allows us to name several objects around us and also allows us to process some amount of visual information (Martin, 2007). This is located at the lower end of the hemisphere, this is responsible for processing language and hearing and contains the auditory cortex.
The other parts of the cortex form associations in other areas of the brain and are involved in several other complex functions of the brain that involve planning, learning, judging, thinking, figuring and spatial reasoning.
The rest of the cortex is responsible for forming associations in the brain that combine both motor and sensory information and are stored in the brain. These are associated information that is responsible for many of the things that distinguish us as humans.
Conclusion
This article answered the question of how the brain controls human behaviour. It discusses every part of the brain and its functions in the human body, along with some frequently asked questions about the same.
Frequently Asked Questions: How Does the Brain Control Human Behavior?
Are all human behaviours controlled by the brain?
It is most likely that our behaviours result from a complex interplay between each of our genetic make-up, brain chemistry and functioning and the economic, social and psychological environments in which we grew up and live.
What part of the brain controls behaviour and personality?
Prefrontal Cortex – The term prefrontal cortex refers to the very front part of the brain located behind the forehead and above the eyes. It appears to play a critical role in the regulation of emotion and behaviour by anticipating the consequences of our actions and inhibiting behaviours.
How does the brain make decisions?
It is well known that the decision-making process results from communication between the prefrontal cortex (working memory) and hippocampus (long-term memory). However, there are other regions of the brain that play essential roles in making decisions, but their exact mechanisms of action still are unknown.
References
Best, M. D. (2009). Click chemistry and bioorthogonal reactions: unprecedented selectivity in the labeling of biological molecules. Biochemistry, 48(28), 6571-6584.
Bower, J. M., & Parsons, L. M. (2003). Rethinking the “lesser brain”. Scientific American, 289(2), 50-57.
Fritsch, G., & Hitzig, E. (2009). Electric excitability of the cerebrum (Über die elektrische Erregbarkeit des Grosshirns). Epilepsy & Behavior, 15(2), 123-130.
Gibson, K. R. (2002). Evolution of human intelligence: The roles of brain size and mental construction. Brain, behavior and evolution, 59(1-2), 10-20.
Klüver, H., & Bucy, P. C. (1939). Preliminary analysis of functions of the temporal lobes in monkeys. Archives of Neurology & Psychiatry, 42(6), 979-1000.
Martin, A. (2007). The representation of object concepts in the brain. Annual review of psychology, 58, 25.
Sherman, S. M., & Guillery, R. W. (2006). Exploring the thalamus and its role in cortical function. MIT press.
Sigurdsson, T., Doyère, V., Cain, C. K., & LeDoux, J. E. (2007). Long-term potentiation in the amygdala: a cellular mechanism of fear learning and memory. Neuropharmacology, 52(1), 215-227.
