The Brain: Source of Thought and Knowledge Definition of Brain The brain is the organ in the head that controls all functions of the human body. The brain also allows humans to think and solve problems. Therefore, brain health is very important to maintain so that the body's functions can run properly. The brain is protected by a wrapping layer called the brain membrane (meninges) and skull bones, and is connected to the spinal cord. Together with the spinal cord, the brain acts as the body's control center and composes the central nervous system. This nervous system then works together with the peripheral nervous system to give humans the ability to perform various activities, such as walking, speaking, breathing, and eating and drinking. The brain regulates and coordinates most movements, behaviors and homeostatic body functions such as heart rate, body fluid balance and body temperature. The human brain is responsible for the regulation of the entire body and human thinking, therefore there is a close link between the brain and human thinking. Knowledge about the brain influenced the development of cognitive psychology. The brain is also responsible for functions such as recognition, emotions, memory, motor learning and all other forms of learning. The brain is a tool for processing data about the internal and external environment of the body received by receptors on the sensory organs (such as eyes, ears, skin and others). The data is transmitted by the nerve fibers known as the entire nervous system. Parts of the Brain 1. Cerebrum The cerebrum is the largest part of the human brain. The function of the cerebrum is to regulate movement and coordination of movement, touch, vision, hearing, judgment, reasoning, problem solving, emotions, and learning. The cerebrum consists of two hemispheres, namely the right brain and the left brain. The right hemisphere has the function to control movement on the left side of the body, while the left hemisphere regulates movement on the right side of the body. The right and left hemispheres are separated by a groove called the longitudinal fissure. The two sides of the brain are joined at the bottom by the corpus callosum, which functions to transmit messages from one part of the brain to the other. The surface of the cerebrum has a distinctive folded appearance called the cerebral cortex. The cerebral cortex is the thin outer layer of gray matter that encloses the brain, with a thickness of 2-3 millimeters. 2. Cerebellum The cerebellum is located below the cerebrum at the back of the brain, under the occipital lobe. Just like the cerebrum, the cerebellum also has 2 hemispheres. The cerebellum is responsible for controlling movement, maintaining balance, and regulating the position and coordination of body movements. This part of the brain also plays a role in controlling fine motor skills, such as writing and painting, hand and foot coordination. The cerebellum or the back of the brain functions in body balance, posture, and equalization of left and right brain functions (equilibrium). 3. Brain Stem The brain stem is a bundle of nerve tissue at the base of the brain, located in front of the cerebellum. It functions as a transmitting station that connects the cerebrum to the spinal cord, and sends and receives messages between different parts of the body and the brain. Human Brain Development With increasing age, the ability or function of the brain decreases, one example is dementia or senile dementia, which is a decline in intelligence, including memory, abstraction, language, perception, orientation, and emotions (Markam, 2009). Dementia is a cognitive decline that interferes with daily activities and social activities (Muhammad, 2010). Cognitive decline in the elderly usually begins with memory decline or forgetfulness (Nugroho, 2008). Dementia is common in the elderly. There are cognitive changes that occur in the elderly, including reduced ability to remember intellectual functions, reduced efficiency of nerve transmission in the brain (causing the information process to slow down and a lot of information is lost during transmission), as well as reduced ability to accumulate new information and retrieve information from memory, and the ability to remember events that have just occurred. One way to maintain cognitive function in the elderly is by stimulating and stimulating the brain and resting with sleep, activities such as reading, listening to news and stories through the media (Gunadi, 2010). One way to stimulate with Brain Gym. When a Baby is Born At birth, the human brain already has almost all the neurons it will have for the rest of its life. However, the connections between these cells are still developing. Myelin, a fatty substance that protects axons and helps impulses travel faster, is already produced by the brain near the spinal cord. In terms of size, the average newborn brain is about a quarter the size of the average adult brain. It then doubles in size in the first year of life. In terms of weight, the average newborn brain weighs about one pound or the equivalent of 500 grams and grows about two pounds or about 1 kg during childhood. Childhood Entering the age of three, the size of the human brain continues to grow to about 80 percent of adult size. At this age, the brain actually has more than 200 percent synapses. A synapse is the connection between an axon and a nerve cell that allows information to flow between them. By the age of five, a child's brain size has reached 90 percent of that of an adult. Brain development also becomes sharper at this age. Every experience a child has will form a synapse. Adolescent Age The size and weight of the adolescent brain is not much different from that of an adult. At this age, the myelin that was already formed when the baby was born has a more complex circuit. The final set of myelin is in the frontal lobe, behind the forehead, which functions for decisionmaking, impulse control and empathy. However, these functions are not as mature as those of adults. Therefore, many teenagers often experience anxiety or emotional instability. Adult Age When entering adulthood, the size and weight of the brain is much more developed than before. At this time, the average weight of a woman's brain is about 2.7 pounds or 1.2 kg, while a man's is about 3 pounds or 1.3 kg. By the age of 20, brain development in the frontal lobe is finally complete, especially in the ability of judgment. However, brain development will also begin to decline slowly in this age range. The body will naturally form and eliminate nerve cells and brain cells at the same time. Advanced Age By the age of 50, your memory starts to become shorter or you forget things more easily. This is because natural aging changes the size and function of the brain. The reduction in brain capabilities is entirely due to the death of brain cells and synapses. The brain shrinks and the risk of various brain-related diseases increases. Between Brain and Mind The human brain can be analogized to the hardware of a computer. While the mind, like the software. That said, the human brain actually has extraordinary abilities. The existing hardware capacity according to various opinions can produce creations and achievements many times what most humans achieve or produce. That if someone thinks they can achieve or realize something. Then it is true that finally something will be achieved or realized. Conversely, if you think you cannot, then it is true that you will not be able to. Unfortunately, most of our family and society environment scares more than encourages being brave, doubts more than fosters hope, is more pessimistic and skeptical than optimistic, would rather not fail, even though we have never had success, criticizes more than appreciates. This is the mistake in installing software. It is the dominant attitude of fear, lack of confidence, and also laziness.