Psychology 12 What makes us into the people we are today? What separates us from animals? What is the “mind”? Is it simply the grey organ nestled inside every human head—or something more? Is it flesh or spirit? Does the mind control the body or vice versa? To understand the mind and thus people, first, we must look at our biological make-up to determine how we perceive the world and interact with it… It’s almost like running is this great friend we both share…Anyways, that’s what I’d like to talk to you about…running as a friend, a companion…in other words, the relationship of running. “WHAT!?” many of you will be saying, “I thought that I was going to learn about how to improve my 10k time.” Go read “Runner’s World” for that. You see, I don’t view running as what I DO or what I AM, but as this thing, this force, that changes me over time… ---from “Running and Me: A Love Story” by Joan Nesbit, 1999 Why One does the writer love running so much? of the reasons may be that people who do a lot of running—especially longdistance running, often talk of an effect called a “runner’s high.” The longer they run, the more tired they get, of course; but at some point, the runners will “push through the wall” and “get their second wind.” Why does this happen? Why does the writer love running so much? Why does this happen? Endorphins, which are neurotransmitters, produce the euphoria of a runner’s high. As the body deals with a very physically stressful situation—running---the runner’s body reacts to stress. What other types of physically stressful situations may the human body encounter? How do you think the nervous system will react? The nervous system controls your emotions, movements, thinking and behaviour. Structurally, it is divided into two parts—the central nervous system [CNS] ( the brain and the spinal cord) and the peripheral nervous system [PNS] (the smaller branches of nerves that reach the other parts of the body. All parts of the nervous system are protected: the brain by the skull and several layers of sheathing, the spinal cord by the vertebrae, and the peripheral nerves by layers of sheathing. The bony protection of the spinal cord is vital. An injury to the spinal cord could prevent the transmittal of messages between the brain and the muscles, and could result in paralysis. http://www.youtube.com/watch?v= NL1S0AhYyFw&feature=relmfu http://www.youtube.com/watch?v=s q9qfSusNmA&feature=related http://www.youtube.com/watch?v=s jyI4CmBOA0&feature=related The brain uses networks of these neurons, so small that 30,000 of them can fit on the head of a pin to process information Your brain has about 100 billion of them! They help you think, learn, move and experience your world. Neurons depend upon support cells called glia. Glia help to insulate, nourish and protect neurons. There are about 9 glia for every neuron. Messenger Molecules Neurons communicate with each other. Within the brain there is a constant “chatter” of cells as they communicate with each other using a language of electrical impulses and chemical signals. Messenger Molecules Information “travels” when electrical impulses within a neuron trigger the release of a burst of messenger molecules (called neurotransmitters or NTs) from the end of the neuron. The NTs then flow into a tiny space called a synapse. . Messenger Molecules The NTs within the synapse then contact the next neuron, triggering another electrical impulse and the continuation of communication along the next neuron. FYI [the synapse is less than one millionth of an inch wide and is filled with fluid that transmits the chemical from one neuron to another] Building Information Highways Neurons connect with each other to form neural networks that serve to carry information from one area of the brain to another. A typical neuron forms 1000 to 10,000 synapses with other neurons, thus forming a neural network. Electrical impulses travel across neurons at speeds up to 400 miles per hour. We can instantaneously tap into a memory, “get” a joke, feel inspired - all because of these neural networks. . Chemical-electrical signals travel down the neurons through the dendrites much as a flame travels along a firecracker fuse. The main difference is that the neuron can fire (burn) over and over again, hundreds of times a minute. Transmission between the neurons, or nerve cells, occur whenever the cells are stimulated—the neuron fires according to the allor-none principle (when it fires, it fires at full strength). REVIEW: The neuron receives messages from other neurons on its dendrites Messages are transmitted down the axon and sent out through axon terminals Neurotransmitters Chemicals released by neurons, which determine the rate at which other neurons fire Neurotransmitters bridge the gap (synapse) between one neuron and the next. There are many types of neurotransmitters Norepinephrine Endorphin Acetylcholine Dopamine Serotonin Neurotransmitters Norepinephrine: involved in learning and memory Endorphin: inhibits pain Acetylcholine: movement and memory. An undersupply is associated with paralysis and Alzheimer’s disease Neurotransmitters; Dopamine: Learning, emotional arousal and movement. An oversupply is linked to schizophrenia—an undersupply is linked to Parkinson’s disease Serotonin: cognitive functions—memory and learning. It also regulates intestinal movements and mood, appetite, sleep, as well as muscle contraction. An undersupply of serotonin and norepinephrine may result in depression Your fingers are dendrites Palm is a nerve cell Your arm is an axon Drugs interfere with neurotransmitters in the brain. 'mind-altering' drugs change our interpretation of the world, our behaviour, and our mood. For example, cannabis, affects neurons releasing acetylcholine, noradrenaline and dopamine LSD mimics serotonin action in the brain, which seems to explain its hallucinogenic effects. Every time someone gets drunk, they kill off nerve cells—similar to the picture below (look at the dendrites) A New Brain Every Day Your brain is “magni-ficient!” Magnificent, and at the same time, efficient, your brain changes and grows to help you function in your life. Your networks are the “behind the scenes” wiring that allow you to express your unique qualities. You might have passed by old railroad tracks with wildflowers growing nearby. In the past: believed that brain connections were like railroad tracks – basically permanent, with no significant growth and development during adulthood. In aging-- neurons and connections would fade away like old defunct railroad tracks. This view left little hope of reversing memory loss or building up cognitive reserves to promote brain health in aging. Learned that neurons are more like wildflowers rather than railroad tracks. Found that new neurons sprout throughout life. The brain naturally develops by balancing periods of exceptional growth - called “blooming” - with periods of trimming back or “pruning.” But things we do in everyday life – exercise, learning something new – also promote sprouting of new neurons. How nerve cells work: http://www.youtube.com/watch?v=c5cab4 hgmoE&feature=related http://www.youtube.com/watch?v=CMnDi epv5Os&feature=related http://www.youtube.com/watch?v=NL1S0A hYyFw&feature=relmfu Draw and label the parts of a neuron, and describe the parts Complete questions 2 & 5 on page 159. Remember early psych methods… Studying the bumps on a person’s skull to determine that person’s intellect and character traits… Luckily, we’ve come a long way from this theory… But—it did encourage scientists to examine the role of the brain in human and behaviour. Dr. Broca (resp. for Broca’s Area) A patient of Dr. Broca suddenly lost his ability to speak—but otherwise normal For 30 years, he could only utter one syllable “Tan”—became known as Mr. Tan. Dr. Broca performed an autopsy on his brain—what he found stunned scientists. An area of the brain, as large as an egg had completely deteriorated Since Tan’s behaviour was normal, this meant his speech was controlled specifically by the diseased area Broca had new scientific evidence that contradicted prior knowledge of the brain: every part of the brain controls every kind of behaviour (prev. understanding) In fact, Tan showed this idea to be wrong--the control of one specific behaviour, like speech was localized in one specific area/part of the brain. Mapping Behaviour in the Brain: 1870 France went to war with Germany…two German doctors roamed the battlefields for dying men…looking for soldiers who skulls were blown open from gunfire. They used an electrically charged mental probe which applied to the surface of exposed brain… Found: Stimulation to the same brain area always resulted in movement of the dying man’s arms and legs. This confirmed Broca’s findings & created a new research tool for understanding the brain Electrical probes to map the location of behaviour in the brain—discovered that our psychological experiences are controlled by nerve cells in 4 sections or lobes of the brain’s cerebral cortex… Each lobe exists on both sides of the brain—because the brain’s cerebrum is divided into two identical hemispheres. Dr. Penfield (1940s) He devoted much thinking to the functioning of the mind, and continued until his death to contemplate whether there was any scientific basis for the existence of the human soul Dr. Penfield (1940s) Electrical probes to damaged brains of patients Stimulated movement and the senses, but also memories and actual mental experiences Some saw themselves at concert halls, games, heard music, saw neighbours, and heard people calling them… Dr. Penfield (1940s) His patients weren’t physically perceiving real games or listening to music—but they had purely mental experiences His experiment stimulated mental behaviour... We’ve learned about the brain’s role in behaviour—but what does this experiment tell us of the mind? Will we ever understand the mind/body question…? Modern psychologists study the physical structure and our behaviours—perhaps this will lead us to understanding the “mind” Charles Whitman --Killed wife and mother & 47 people from top of tower --People thought he must be crazed, but those who knew him said he was normal… Charles Whitman --Wrote a letter 24 hours before killing spree. He complained of headaches and weird thoughts and wanted an autopsy done after his death. --Found he had a tumor the size of a walnut pressing down on an area in his brain that is responsible for aggression. Charles Whitman His mental illness could have been physical. His apparent healthy “mind” could only wander helplessly while his diseased body destroyed it. Lets look at the brain in our understanding of behaviour…not the “mind” We begin our exploration of the brain at the lower end, where the spinal cord joins the base of the brain, and then continue upward toward the skull. Note that as we move from bottom to top, “lower,” basic processes like breathing generally give way to “higher,” more complex mental processes. The brain is the control center of the body. Made up of dense "grey matter" consisting of complicated networks of interconnected neurons the brain can be superficially divided into three main parts: the hindbrain, the midbrain and the forebrain. Also, the large section labeled as the BRAINSTEM includes parts of all three of these3 sections and helps regulate reflex activities important to survival (ie, heartbeat and respiration) Throughout the tour, note that certain brain structures are specialized to perform certain tasks, a process known as localization of function, but also note that most parts of the brain are not so specialized—they perform overlapping functions. Have you ever wondered what allows you to automatically breathe and your heart to keep pumping—automatic behaviours and survival responses like these are either controlled by or influenced by parts of your hindbrain, which includes the medulla, pons and cerebellum. Medulla: Essentially is an extension of the spinal cord, with many nerve fibers passing through it carrying information to an from the brain. It also controls many essential automatic brain functions like respiration and heartbeat. Cerebellum: (“little brain”) is evolutionarily, a very old structure. It coordinates fine muscle movement and balance. The cerebellum coordinates the muscles so that movement is smooth and precise. It is also crucial for our sense of balance and equilibrium Pons: Located above the cerebellum and medulla, is involved in respiration, movement, sleeping, waking, and dreaming (among other things). It also contains many axons that cross from one side to the other (pons is Latin for “bridge”) The midbrain is the small part of the brain that helps orient our eye and body movements to visual and auditory stimuli, and works with the pons to help control sleep and level of arousal. It also contains a small structure involved with the neurotransmitter dopamine, while deteriorates in Parkinson’s disease. Running through the core of the hindbrain, midbrain, and brainstem is the reticular (netlike) formation (RF). This finger-shaped network of neurons filters incoming sensory information and alerts the higher brain centers to important events. Without your RF, you would not be alert or perhaps even conscious. In fact, some general anestheics target the RF so pain sensations never register in the brain. The Forebrain is the largest and most prominent part of the human brain. It includes the thalamus, hypothalamus, limbic system, and cerebral cortex. The first three structures are located near the top of the brainstem. Wrapped around them is the Cerebral cortex (cerebrum is Latin for “brain,” and cortex is Latin for “covering”) Thalamus: Resembling two little footballs jointed side by side, the thalamus serves the major sensory relay center for the brain. Thalamus: major sensory relay center for the brain. Like an air traffic control centre that receives information from all aircraft and then directs them to the appropriate landing or takeoff areas, the thalamus receives input from nearly all the sensory systems and then directs this information to the appropriate areas. Thalamus: major sensory relay center for the brain. For example, while you are reading this, your thalamus sends incoming visual signals to the visual area of your cortex. While listening to music, the information is transferred to the auditory area of the cortex. Thalamus: Integrates input from the senses Thalamus: In addition to relaying sensory information to the cortex it also integrates information from various senses and maybe involved in learning and memory. Thalamus: Integrates input from the senses Thalamus: integrates information Injury to the thalamus can cause deafness, blindness, or loss of any other sense (except smell). Thalamus: Integrates input from the senses Thalamus: integrates information Damage may cause the cortex to misinterpret or not receive vital sensory info. Interestingly, brain-imaging research links thalamus abnormalities to schizophrenia (a serious psychological disorder involving problems with sensory filtering and perception). Hypothalamus: Controls basic drives, such as hunger Hypothalamus: Beneath the thalamus lies the hypothalamus (“hypo” meaning “under”). Although no larger than a kidney bean, it has been called the master control centre” for basic drives such as hunger, thirst, sex, and aggression. Hypothalamus: Controls basic drives, such as hunger Hypothalamus: It also helps govern hormonal processes by regulating the endocrine system. Hanging down from the hypothalamus, the pituitary gland is considered the key endocrine gland because it releases hormones that activate the other endocrine glands. The endocrine system is a system of glands, each of which secretes a type of hormone into the bloodstream to regulate the body. Limbic System: Regulates fear and other emotions Limbic System: An interconnected group of forebrain structures, known as the limbic system, is located roughly along the border between the cerebral cortex and the lower-level brain structures (hence the term “limbic,” which means “edge” or “border”). Structures include the hippocampus, amygdala, thalamus, hypothalamus. Responsible for emotions, drives, and memory, and involved in forming and retrieving memories. Limbic System: Regulates fear and other emotions Limbic System: The major focus of interest in the limbic system, and particularly the amygdala, has been its production and regulation of emotions (e.g., aggression, pleasure, arousal and fear) Limbic System: Regulates fear and other emotions Limbic System: focus on the amygdala (fear, pleasure, arousal) Also known for its role in pleasure or reward. A study done with rats—stimulating certain areas of the limbic system—cause a ”pleasure” response. The feeling was so rewarding that he rats would cross electrified grids, swim through water (which they normally avoid), and press a lever thousands of times until they collapsed from exhaustion—just to have this area of their brains stimulated. Limbic System: Regulates fear and other emotions Limbic System: focus on the amygdala (fear, pleasure, arousal) Damage to the front part of the cortex which connects to the amygdala and other parts of the limbic system, can permanently impair social and emotional behaviour. This is yet another example of the inseparable interconnectivity of the brain. Cerebral Cortex: Governs higher mental processes, such as thinking Cerebral Cortex: The centre for “higher” processing. The gray, wrinkled cerebral cortex is responsible for most complex behaviours and higher mental processes. It plays such a vital role in human life that may consider it the essence of life. Without a functioning cortex, we would be almost completely unaware of ourselves and our surroundings. Cerebral Cortex: Convolutions Although it is only about ¼ inch thick, it is made up of approximately 30 billion neurons and nine times as many supporting cells. When spread out--cover an area the size of a standard newspaper page. How does your cortex, along with all your brain structures fit inside your skull? Imagine crumpling and rolling a newspaper sheet into a ball—you would retain the same surface area, but in a much smaller space. The cortex contains “wrinkles” called “convolutions” allowing it to hold billions of neurons in the restricted space of the skull. Cerebral Cortex: Hemispheres If you’ve ever watch brain surgery on TV—once the skull has been opened, you’ll first see a gray, wrinkled, cerebral cortex that closely resembles an oversized walnut. Like a walnut, the cortex has a similar division (fissure) down the centre, which marks the left and right hemispheres of the brain. They hemispheres are connected by a band of fibers called the corpus callosum. Cerebral Cortex: Hemispheres. The two hemispheres make up about 80% of the brain’s weight and they are mostly filled with axon connections between the cortex and other brain structures. Each hemisphere controls the opposite side of the body… Are you right brained or left brained? Cerebral Cortex: Hemispheres & Lobes of the Brain The two cerebral hemispheres are divided into eight distinct areas, or lobes—four in each hemisphere. Like the lowerlevel brain structures, each lobe specializes in somewhat different tasks—another example of localization of function. However, some functions overlap between lobes. 1. 2. 3. 4. Each lobe exists on both sides of the brain because the brain’s cerebrum is divided into two identical hemispheres (L&R) Cerebral Cortex: Lobes Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe 1. 2. 3. 4. Cerebral Cortex: Lobes Frontal Lobe: Receives and coordinates messages from other lobes; motor control, speech production, and higher functions. Includes the motor cortex which controls voluntary movements and Broca’s area which controls speech production Parietal Lobe: Receives information about pressure, pain, touch, and temperature. Includes the Somatosensory cortex which receives sensory messages. Occipital Lobe: visual perception and vision—includes the Visual cortex that receives and processes visual information Temporal Lobe: Hearing, language, comprehension, memory, and some emotional control—includes Wernicke’s area that controls language comprehension Cerebral Cortex: Frontal Lobes The largest of the lobes, the two frontal lobes are located at the top front portion of the brain hemispheres—right behind your forehead. They receive and coordinate messages from all other lobes, while also being responsible for at least 3 other functions: higher functions, speech production and motor control 1. Higher functions—functions that distinguish us from other animals, such as thinking, personality, emotion, and memory. Damage to the frontal lobes affect motivation, drives, creativity, self-awareness, initiative, reasoning, and emotional behaviour. Abnormalities in FL are often observed in patients with schizophrenia 1. Cerebral Cortex: Frontal Lobe Functions Higher functions—those that distinguish us from other animals, such as thinking, personality, emotion, and memory. Damage to the frontal lobes affect motivation, drives, creativity, self-awareness, initiative, reasoning, and emotional behaviour. Abnormalities in FL are often observed in patients with schizophrenia Cerebral Cortex: Frontal Lobe Functions 2. Speech Production: In the left frontal lobe, on the surface of the cortex near the bottom of the motor control area lies Broca’s area, which is known to play a crucial role in speech production. . Cerebral Cortex: Frontal Lobe Functions 3. Motor Control: At the very back of the frontal lobes lies the motor cortex, which sends messages to the various muscles that instigate voluntary movement. When you call a friend on a cell phone, the motor control area of your frontal lobes guides your fingers to press the desired sequence of numbers. Cerebral Cortex: Parietal Lobes At the top of the brain, just behind the frontal lobes, are the two parietal lobes. They contain the Somatosensory cortex, which interpret bodily sensations including pressure, pain, touch, temperature, and location of body parts. When you step on a sharp nail, you quickly (and reflexively) withdraw your foot because the messages travel directly to and from your spinal cord. However, you do not experience “pain” until the neural messages reach the parietal lobes of the brain. Cerebral Cortex: Temporal Lobes The two temporal lobes (Latin for “pertaining to the temples”)are responsible for auditory perception (hearing), language comprehension, memory, and some emotional control. The auditory cortex (which processes sound) is located at the top front of each temporal lobe. This area processes incoming sensory information from the ears and sends it to the parietal lobes, where it is combined with visual and other sensory info. In the LEFT temporal lobe, Wernicke’s area is involved in language comprehension. Cerebral Cortex: Temporal Lobes The auditory cortex (which processes sound) is located at the top front of each temporal lobe. This area processes incoming sensory information from the ears and sends it to the parietal lobes, where it is combined with visual and other sensory info. In the LEFT temporal lobe, Wernicke’s area is involved in language comprehension. Cerebral Cortex: Temporal Lobes In the LEFT temporal lobe, Wernicke’s area is involved in language comprehension. Wernicke’s Area: German neurologist Carl Wernicke noted patients with damage to this area could not understand what they read or heard, but they could speak quickly and easily. Unfortunately, their speech was often unintelligible. It contained made-up words, sound substitutions (girl became curl) and word substitutions (bread became cake). This syndrome is now referred to as Wernicke’s aphasia. Cerebral Cortex: Occipital Lobes (Latin “oh,” “in the back of,” and “caput,” “head”)—located at the lower back of the brain. Occipital lobes are responsible for vision and visual perception. Damage to this area can produce blindness, even though the eyes and their neural connection to the brain are perfectly healthy. The occipital lobes are involved in shape, colour, motion, and perception. Split-Brain Surgery: Cutting of the corpus callosum to separate the brain’s two hemispheres. When used medically to treat severe epilepsy, split-brain patients provide data on the functions of the two hemispheres. This information has profoundly improved our understanding of how the two halves of the brain function. Split-Brain Surgery: . One split-brain patient found that when he dressed himself, he sometimes pulled his pants down with his left hand and up with his right. However, generally most patients show very few outward changes in behaviour, other than fewer epileptic seizures. The subtle changes normally appear only with specialized testing. Hemispheric Specialization: although complex activities occur in both hemispheres, specialization of function occurs in some areas Left Hemisphere: 1. Language Functions: speaking, reading, writing, and understanding language 2. Emotions: Associated with positive emotions 3. Analytical: Figures things out step by step 4. Controls and senses the right side of the body Hemispheric Specialization: although complex activities occur in both hemispheres, specialization of function occurs in some areas Right Hemisphere 1. Nonverbal Abilities: Music, art, perceptual and spatial-manipulative skills, recognition of faces, patterns and melodies, some language comprehension 2. Emotions: Associated with negative emotions, emotion expression, and emotion perception 3. Synthetic: figures things out by combining to form wholes 4. Controls and senses the left side of the body. Imagine yourself as a high school football player (not too difficult for some!). If you suffered a concussion while playing a game, would you tell your coach? There is mounting evidence linking multiple concussions with permanent (and possibly fatal) brain damage… According to a report, “many of the 1.2 million teenagers who play high school football either don’t know what a concussion is or they simply don’t care. They continue to play on and get hurt much worse—sometimes fatally.” Millions of people suffer head injuries each year, and most of these injuries are minor—thanks to the bony skull’s protection for the brain. This is not the case for traumatic brain injuries (TBI). TBI is defined as an injury to the brain caused by significant trauma Symptoms: (range from mild to severe): headache, loss of consciousness, convulsions, coma and death. Two most common brain injuries are concussions (result from significant blow to the head) and contusions (bruises to the brain). Either TBI can result in prolonged or nonreversible brain damage and serious problems, such as extreme changes in personality, significant loss of motor skills, emotional control, and mental abilities A) Questions: Answer questions 3, 4 & 5 on page 168. B) Read the Case Study on page 169 Answer the following questions: How does split-brain surgery benefit both the patient and humans in general? Should splitbrain surgery ever be performed on a person with no brain disorders? Complete questions 1-3 from the case study. Let’s work with our right hemispheric spatiomanipulative skills—we are going to build a 3-D version of the brain. Objective: To gain a better understanding of the location and function of the parts of the brain Using your textbook, the slides and the chart you created yesterday as guides, create a 3-D cross section of the left side of the brain, making sure to include all the structures listed in your charts (obviously, none from the right hemisphere) Use a numbering system on the appropriate sections of the brain (attached with sticky notes & toothpicks) and write the corresponding names of the structures and their functions on card stock (recipe cards).. Read the Time article on page 180-1. Answer the Analyzing the Article Questions 1-2