BRAIN: CONTROL CENTER

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1 BRAIN: CONTROL CENTER

2 ORCHESTRA Scientists now believe the brain functions much like an orchestra, where different instruments each play a different part. Scans show that the brain divides different aspects of a task according to constellations of different brain regions, but scans also show that there is no single brain area for each and every function. Consciousness is the ultimate blanket function of the brain. People s range of mental activities is related to the brain s structural variation.

3 AMAZING The human brain is composed of about 100 billion neurons. But even more awesome than that are the synaptic connections between brain cells. There are up to 100,000 connections onto any one brain cell. However, the most amazing thing about being born human is that as that as you grow your brain connections grow with you. So, although you are born with pretty much all the brain cells you will ever have, it is the growth of the connections after birth that accounts for the growth of your brain. Your brain will relate to whatever you do. The brain is sensitive to your experiences. It makes you the individual that you are.

4 The brain s ability to reorganize is called plasticity. Even into old age, one s brain remains continuously plastic constantly dynamic, constantly evolving and changing, mirroring whatever happens to you. Connections reflect one s experiences, and in turn influence one s perceptions of the world. PLASTICITY

5 What is the mind? Is it what one researcher claims, the personalization of the brain? Consciousness can be defined as awareness of oneself and one s environment. One can lose consciousness but not necessarily lose one s mind. MIND

6 CHEMICAL FOUNTAINS Chemical transmission is the The level of cornerstone of brain function. This consciousness may be is what really distinguishes our linked to the number of brains from computers. Computers are not conscious. Chemicals in our brain cells and brains influence our perceptions, connections between cells. bodily functions, feelings, and consciousness. Does consciousness grow and change as our brains grow and change? There is no one center for consciousness in the brain. Many brain regions contribute to it. We are always conscious of something. One has hardwired circuits but also chemical fountains in the brain.

7 INTERCONNECTIONS Some researchers suggest that childhood, dreaming, schizophrenia, fast-paced sports, and even raves are all examples of where the mind is not being accessed for different reasons: lack of connectivity (childhood), lack of strong sensory stimulation (dreams), an imbalance with those fountains of chemicals (schizophrenia), or a degree of competition from other stimulations (fast-paced sports and raves, where people are often using drugs that confuse those chemicals). The brain is an integral part of the body. Your central nervous system, hormones, and immune systems are all interlinked. Otherwise, biological anarchy would reign. The human brain s interconnections exceed the Internet s by an astronomical number.

8 BRAIN FACTS Weight: 3 pounds Shape: walnut Color: uncooked liver The brain is divided into two hemispheres called the cerebral cortex (commonly known as the conscious thinking center), covered in a thin skin of deeply wrinkled gray tissue, and separated by the corpus callosum. That curved band of white tissue acts as a bridge between the two halves, shuttling information at such a rate of speed that for all practical purposes the two hemispheres act as one. With the exception of the pineal gland, every brain module is duplicated in each hemisphere another of nature s creative duplicating systems.

9 CEREBRAL CORTEX The cerebral cortex is the outer surface of the brain surrounding the cerebral hemispheres. It contains small grooves called sulci and large grooves called fissures and bulges between adjacent sulci or fissures called gyri. The cerebral cortex processes all perceptions and complex thoughts. In evolutionary terms, it is the most recently developed brain structure.

10 THREE DIVISIONS The brain can be divided into the hindbrain, the midbrain, and the forebrain.

11 HINDBRAIN The hindbrain is located in the bottom portion of the brain and is an extension of the spinal cord. In evolutionary terms, it is the oldest portion of the brain. The major components of the hindbrain are: Medulla: the oblong structure at the top of the spinal cord that controls many life-support functions such as breathing, heart rate, and blood pressure. Pons: located above the medulla. Connects the lower brain regions with higher brain regions. The pons is important for sleep, dreaming, and arousal. Pons means bridge. Cerebellum: located at the rear of the brain and controls movement, coordination, balance, muscle tone, and learning motor skills. Resembles a miniature version of the cerebrum. Reticular Activating System: monitors the general level of activity in the hindbrain and maintains a state of arousal. Keeps the brain awake even during sleep. The RAS is part of the reticular formation, which extends to the upper portion of the midbrain.

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13 MIDBRAIN The midbrain continues upward from the pons portion of the hindbrain and lies between the hindbrain and the forebrain. It consists of an upper portion called the tectum, and a lower part, the tegmentum. The tectum functions in the visual and auditory systems. The tegmentum contains part of our sleep and arousal system and contains centers for eye movements. The midbrain relays sensory information from the spinal cord to the forebrain.

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15 FOREBRAIN The forebrain is the largest and most highly developed portion of the brain. The major components are: Cerebrum: The largest part of the forebrain and responsible for complex mental activities. Its outer surface is the cerebral cortex and is divided into two cerebral hemispheres. Contains four major lobes: the frontal lobe that controls voluntary movement and includes the motor cortex; the parietal lobe that contains the primary somatosensory area that manages skin senses; the occipital lobe is located at the back of the head and contains the visual cortex; and the temporal lobe contains the auditory cortex and is located on each side of the head above the temples. Corpus Callosum: Enormous communication network that connects the right and left hemispheres.

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17 The areas lying beneath the corpus callosum make up the limbic system, the area that relates to the unconscious and yet profoundly affects our experience. Its job is to feed information upward to the conscious cortex. Emotions are generated in the limbic system along with many urges that direct our behavior and usually help in survival. The related structures of the limbic system control emotion, motivation, and memory. LIMBIC SYSTEM

18 OTHER MAJOR PARTS OF FOREBRAIN Thalamus Relays and translates information from all of the senses, except smell, to higher levels of the brain. Directs incoming information to the appropriate part of the brain for further processing. Plays an especially important role in attention. Hypothalamus Plays a major role in the regulation of basic biological drives and controls autonomic functions such as hunger, thirst, and body temperature. Regulates the pituitary gland, which adapts the body to the environment by constantly adjusting hormones. It is heavily involved with motivation as well. Amygdala Registers and generates fear. Helps regulate emotion. Basil ganglia Plays a part in motor control, the extrapyramidal motor system, and emotion. The cerebral cortex is the center of most of our higher order cognitive processes.

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20 BRAIN-BASED LEARNING People process all incoming information through a vast number of interdependent networks, and any information already stored influences how and what they learn. Every time people speak, move, or think, electrical and chemical communications are taking place among tens of thousands of neurons.

21 NEUROSCIENCE Scientists use imaging technologies to understand memory, recall, and how the brain manages information. They also utilize imaging technology to learn how the brain develops and then functions to perceive, think, move, and remember. Among the methods used are: MRI, fmri, PET scan, and CAT scan.

22 PHINEAS GAGE What happened to Gage? The iron rod went in under Gage's cheekbone, and came out through the top of his head. It destroyed most of the front of the left part of his brain. Modern-day patients with the same area of brain damage are affected in the same way. They show no reaction to emotional events, and are unable to make personal or social decisions. They cannot plan, even a few hours ahead. These patients show how important emotions are to our powers of reasoning.

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