When you think of the human nature, you cannot disconnect it from the brain. Our main definition is how the human brain works and that is why it becomes essential for you to understand everything that pertains to it. The brain is a fascinating and complex organ. It is responsible for senses, movement and control, emotions and feelings, language and communication, thinking and memory. Increasing our own knowledge of the brain helps us understand our own bodies better (Hydrocephalus Association, 2011). This same view is maintained by Mayfield in its introduction to the overview of the brain that “The brain is an amazing three-pound organ that controls all functions of the body, interprets information from the outside world, and embodies the essence of the mind and soul. Intelligence, creativity, emotion, and memory are a few of the many things governed by the brain. Protected within the skull, the brain is composed of the cerebrum, cerebellum, and brainstem.” Having confirmed the uniqueness of the brain from different scholarly sources, it is good to proceed to understand the way it affects our daily living.
The brain receives information through our five senses: sight, smell, touch, taste, and hearing – often many at one time. It assembles the messages in a way that has meaning for us, and can store that information in our memory. The brain controls our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body. The central nervous system (CNS) is composed of the brain and spinal cord. The peripheral nervous system (PNS) is composed of spinal nerves that branch from the spinal cord and cranial nerves that branch from the brain (Mayfield, 2019).
Talking about the brain, it is composed of the cerebrum, cerebellum, and brainstem.
Cerebrum: is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement.
Cerebellum: is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance.
Brainstem: acts as a relay center connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing (Mayfield, 2019).
The Pons is in front of the cerebellum and coordinates the activities of the cerebrum and the cerebellum by receiving and sending impulses from them to the spinal cord. The Medulla is part of the brainstem situated between the pons and the spinal cord and it controls breathing, heartbeat, and vomiting. There are many other anatomical features of the brain which specialize in various activities. The Meninges consist of three membranes which cover the brain and spinal cord including the dura mater, the arachnoid membrane and the pia mater. They completely surround the brain and spinal cord (Hydrocephalus Association, 2011).
The brain can be further understood when the cerebrum is classified into two halves: the right and left hemispheres. They are joined by a bundle of fibers called the corpus callosum that transmits messages from one side to the other. Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed. Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The left hemisphere is dominant in hand use and language in about 92% of people (Mayfield, 2019). The right hemisphere, controlling the left half of the body, manages nonverbal processes, such as attention, pattern recognition, line orientation and the detection of complex auditory tones. Although the two hemispheres are in continual communication with each other, each acting as independent parallel processors with complementary functions, the dominant left-hemisphere appears most closely associated with a conscious self (Web-Us, 2019).
Now, let’s discuss the nexus between the brain and language. In general, the left hemisphere of the brain is responsible for language and speech and is called the “dominant” hemisphere. The right hemisphere plays a large part in interpreting visual information and spatial processing. In about one third of people who are left-handed, speech function may be located on the right side of the brain. Left-handed people may need special testing to determine if their speech center is on the left or right side prior to any surgery in that area. Aphasia is a disturbance of language affecting speech production, comprehension, reading or writing, due to brain injury – most commonly from stroke or trauma. The type of aphasia depends on the brain area damaged.
Broca’s area: lies in the left frontal lobe. If this area is damaged, one may have difficulty moving the tongue or facial muscles to produce the sounds of speech. The person can still read and understand spoken language but has difficulty in speaking and writing (i.e. forming letters and words, doesn’t write within lines) – called Broca’s aphasia.
Wernicke’s area: lies in the left temporal lobe. Damage to this area causes Wernicke’s aphasia. The individual may speak in long sentences that have no meaning, add unnecessary words, and even create new words. They can make speech sounds, however they have difficulty understanding speech and are therefore unaware of their mistakes (Mayfield, 2019).
Memory
Another essential element of the brain is the human memory. Memory is a complex process that includes three phases: encoding (deciding what information is important), storing, and recalling. Different areas of the brain are involved in different types of memory. Your brain has to pay attention and rehearse in order for an event to move from short-term to long-term memory – called encoding.
- Short-term memory, also called working memory, occurs in the prefrontal cortex. It stores information for about one minute and its capacity is limited to about 7 items. For example, it enables you to dial a phone number someone just told you. It also intervenes during reading, to memorize the sentence you have just read, so that the next one makes sense.
- Long-term memory is processed in the hippocampus of the temporal lobe and is activated when you want to memorize something for a longer time. This memory has unlimited content and duration capacity. It contains personal memories as well as facts and figures.
- Skill memory is processed in the cerebellum, which relays information to the basal ganglia. It stores automatic learned memories like tying a shoe, playing an instrument, or riding a bike (Mayfield, 2019).
References
Hydrocephalus Association (2011). Brain 101: An Overview of the Anatomy and Physiology of the Brain. Retrieved from https://www.hydroassoc.org/brain-101-an-overview-of-the-anatomy-and-physiology-of-the-brain/
Mayfield Clinic (2019). Anatomy of the Brain. Retrieved from https://mayfieldclinic.com/pe-anatbrain.htm
Web-Us (2019).Overview of the Brain. Retrieved from http://www.web-us.com/brain/aboutthebrain.htm