Limbic System

Chapter 2.2 Tools of discovery, older brain structures and the Limbic System? 1. What do neuroscientists say? a. The mind is what the brain does Chapter 2.8 1. How do neuroscientists study the brain’s connection to behavior and mind? 2. What is a lesion? a. Destroy tiny clusters of normal or defective brain cells, leaving the surrounding tissues unharmed. 3. In the laboratory, such studies have revealed, for example, that damage to one area of the hypothalamus in a rat’s brain reduces eating, to the point of starvation, whereas damage in another area produces overeating. 4. What can neuroscientists only do today? a. Today’s neuroscientists can also stimulate various brain parts—electrically, chemically, or magnetically—and note the effect. 5. Depending on the stimulated brain part, people may—to name a few examples—giggle, hear voices, turn their head, feel themselves falling, or have an out-of-body experience (Selimbeyoglu & Parvizi, 2010). 6. How can scientists snoop on messages of individual neurons? a. With tips small enough to detect the electrical pulse in a single neuron, modern microelectrodes can, for example, now detect exactly where the information goes in a cat’s brain when someone strokes its whisker. Researchers can also eavesdrop on the chatter of billions of neurons and can see color representations of the brain’s energy-consuming activity. 7. What is optogenetics? a. A technique that allows neuroscietists to control the activity of the individual neurons b. By programming neurons to become receptive to light, researchers can examine the biological basis of fear, smell, memory, and various diseases (Drew et al., 2016; Gradinaru et al., 2009; Liu et al., 2012; Shusterman et al., 2011). 8. What is an eeg? a. Electroencephalogram 9. What does an eeg do? a. Is an amplified readout of such waves b. Researchers record the brain waves through a shower-cap-like hat that is filled with electrodes covered with a conductive gel. Studying an EEG of the brain’s activity is like studying a car engine by listening to its hum. With no direct access to the brain, researchers present a stimulus repeatedly and have a computer filter out brain activity unrelated to the stimulus. What remains is the electrical wave evoked by the stimulus 10. What is an MEG? a. A related technique to an eeg 11. What does an MEG do? a. measures magnetic fields from the brain’s natural electrical activity. 12. How does an MEG work? a. To isolate the brain’s magnetic fields, researchers create special rooms that cancel out other magnetic signals, such as the Earth’s magnetic field. Participants sit underneath a head coil that resembles a hair salon hairdryer. While participants complete activities, tens of thousands of neurons create electrical pulses, which in turn create magnetic fields. The speed and strength of the magnetic fields enable researchers to understand how certain tasks influence brain activity. 13. What did lord chesterfield sat in a 1746 letter to his son? a. You must look into people, as well as at them,” 14. What is a newer neuroimaging technique that gives us the ability to see inside the living brain? a. PET 15. What is PET? a. Positron emission tomography scan b. depicts brain activity by showing each brain area’s consumption of its chemical fuel, the sugar glucose. Active neurons gobble glucose. 16. What percent does the brain consume calories? a. Our brain, though only about 2 percent of our body weight, consumes 20 percent of our calorie intake. After a person receives temporarily radioactive glucose, the PET scan can track the gamma rays released by this “food for thought” as a task is performed. Rather like weather radar showing rain activity, PET-scan “hot spots” show the most active brain areas as the person does mathematical calculations, looks at images of faces, or daydreams. b. To obtain a PET scan, researchers inject volunteers with a low and harmless dose of a short-lived radioactive sugar. Detectors around the person’s head pick up the release of gamma rays from the sugar, which has concentrated in active brain areas. A computer then processes and translates these signals into a map of the brain at work. 17. What is an MRI? a. Magnetic resonance imaging b. rain scans, the person’s head is put in a strong magnetic field, which aligns the spinning atoms of brain molecules. Then, a radio-wave pulse momentarily disorients the atoms. When the atoms return to their normal spin, they emit signals that provide a detailed picture of soft tissues, including the brain. 18. What have MRI’s? Revealed? a. MRI scans have revealed a larger-than-average neural area in the left hemisphere of musicians who display perfect pitch (Schlaug et al., 1995). They have also revealed enlarged ventricles—fluid-filled brain areas (marked by the red arrows in FIGURE 2.12)—in some patients who have schizophrenia, a disabling psychological disorder. 19. What is a special application of MRI? a. fMRI 20. What can an fMRI reveal? a. can reveal the brain’s functioning as well as its structure. Where the brain is especially active, blood goes. By comparing successive MRI scans, researchers can watch as specific brain areas activate, showing increased oxygen-laden bloodflow. 21. How is this done? a. As a person looks at a scene, for example, the fMRI machine detects blood rushing to the back of the brain, which processes visual information (see TABLE 2.2 for a comparison of these techniques). When the brain is unoccupied, blood continues to flow via a web of brain regions called the default network (Mason et al., 2007). Default network brain activity supports mind-wandering and daydreaming (Christoff et al., 2009; Smallwood & Schooler, 2015). b. Insert table 2.2 Types of Neural Measures 22. What does technology enable us to do? a. the technology enables a very crude sort of mind reading. One neuroscience team scanned 129 people’s brains as they did eight different mental tasks (such as reading, gambling, or rhyming). Later, they were able, with 80 percent accuracy, to identify which of these mental activities their participants had been doing (Poldrack et al., 2009). 23. What is functional connectivity a. Helps scientists understand how well differen brain regions work tiger and can offer clues regarding the underlying causes of psychological disorders b. or example, people with major depressive disorder tend to show low connectivity between brain regions involved in experiencing emotion and emotion regulation; these two types of brain regions don’t “talk” very well (Kaiser et al., 2015). This poor neural communication may help explain why people with depression often struggle to regulate their emotions 24. Neuroskeptics a. You’ve seen the pictures—of colorful brains with accompanying headlines, such as “your brain on music.” Hot brains make hot news (Bowers, 2016; Fine, 2010). In one study, students rated scientific explanations as more believable and interesting when they contained neuroscience (Fernandez-Duque et al., 2015). But “neuroskeptics” caution against overblown claims about any ability to predict customer preferences, detect lies, and foretell crime (Satel & Lilienfeld, 2013; Schwartz et al., 2016; Vul et al., 2009a, b). Neuromarketing, neurolaw, nw, neuropolitics, and neurotheology are often neurohype. b. Today’s techniques for peering into the thinking, feeling brain are doing for psychology what the microscope did for biology and the telescope did for astronomy. 25. What is diffusion spectrum imaging? a. A type of MRI tech that maps long distance brain fiber connections. Led to the creation of a new brain map with 100 neural centers not previously described. 26. Today’s techniques for peering into the thinking, feeling brain are doing for psychology what the microscope did for biology and the telescope did for astronomy. From them we have learned more about the brain in the last 30 years than in the previous 30,000. And the next decade will reveal much more, as each year massive funding goes into brain research. Europe’s Human Brain Project promises $1 billion for brain computer modeling. The PsychENCODE project enables researchers to examine differences between the brains of healthy people and those with various disorders, such as autism spectrum disorder, bipolar disorder, and schizophrenia (Akbarian et al., 2015). The $40 million Human Connectome Project seeks “neural pathways [that] will reveal much about what makes us uniquely human and what makes every person different from all others” (2013; Gorman, 2014; Smith et al., 2015). It harnesses the power of diffusion spectrum imaging, a type of MRI technology that maps long-distance brain fiber connections (Jarbo & Verstynen, 2015) (FIGURE 2.13). Such efforts have led to the creation of a new brain map with 100 neural centers not previously described (Glasser et al., 2016). 27. Chapter 2.9 Older Brain structures? 1. What structures make up the brainstem and what are the function of the brainstem, thalamus, reticular formation and cerebellum? 2. An animal’s capacities come from its brain structures. In primitive animals, such as sharks, a not-so-complex brain primarily regulates basic survival functions: breathing, resting, and feeding. In lower mammals, such as rodents, a more complex brain enables emotion and greater memory. In advanced mammals, such as humans, a brain that processes more information enables increased foresight as well. 3. The brain’s complexity arises from new systems built ontop of what? a. The brain’s increasing complexity arises from new systems built on top of the old, much as Earth’s landscape covers the old with the new. b. Digging down, one discovers the fossil remnants of the past—brainstem components performing for us much as they did for our distant ancestors. The Brainstem ---get pictures 1. What is the brainstem? a. The brains oldest and innermost region 2. What is the function of the brainstem? 3. What is the base of the brainstem? a. The medulla 4. What is the medulla? a. The slight swelling in the spinal cord just after it enters the skull. 5. What is the purpose of of the medulla? a. Controls the heartbeat and breathing b. Ex. As some brain-damaged patients in a vegetative state illustrate, we need no higher brain or conscious mind to orchestrate our heart’s pumping and lungs’ breathing. The brainstem handles those tasks 6. What sits above the medulla? a. The pons 7. What is the function of the pons? a. Helps coordinate movements and control sleep 8. What is the brainstem, pons and medulla an extension of? a. The brainstem 9. What is attached to the the top of the brainstem? a. Thalamus. 10. What formation passes through both structures? a. reticular formation 11. As some brain-damaged patients in a vegetative state illustrate, we need no higher brain or conscious mind to orchestrate our heart’s pumping and lungs’ breathing. The brainstem handles those tasks 12. What is the cross wiring of the brain? a. The brainstem is a crossover point, where most nerves to and from each side of the brain connect with the body’s opposite side (FIGURE 2.15). This peculiar cross-wiring is but one of the brain’s many surprises. b. The Thalamus 1. What is the thalamus? a. A pair of egg shaped structures that act a the brain's sensory control center 2. What does the thalamus do? a. The thalamus receives information from all the senses except smell, and routes that information to the higher brain regions that deal with seeing, hearing, tasting, and touching. The thalamus also receives some of the higher brain’s replies, which it then directs to the medulla and to the cerebellum (see below). b. For sensory information, your thalamus is something like London’s Heathrow Airport, a hub through which traffic flows in and out on its way to various locations. The Reticular Formation 1. Where does the reticular formation lie? a. Inside the brainstem between your ears 2. What is the reticular formation? a. It is a neuron network extending from the spinal cord right up through the thalamus. b. As the spinal cord’s sensory input flows up to the thalamus, some of it travels through the reticular formation, which filters incoming stimuli and relays important information to other brain areas. Have you multitasked today? You can thank your reticular formation c. As the spinal cord’s sensory input flows up to the thalamus, some of it travels through the reticular formation, which filters incoming stimuli and relays important information to other brain areas. Have you multitasked today? You can thank your reticular formation 3. Who discovered that the reticular formation also controls arousal? a. Giuseeppe Moruzzi and Horace Magoun 4. What year? a. 1949 5. What experiments did Magoun do? a. Electrically stimulating a sleeping cat’s reticular formation almost instantly produced an awake, alert animal. When Magoun severed a cat’s reticular formation without damaging nearby sensory pathways, the effect was equally dramatic: The cat lapsed into a coma from which it never awakened. 6. Why is it called reticular formation? 7. What is the crossover point where nerves from the left side of the brain are most linked to the right side of the body and vice versa? a. Brainstem The Cerebellum 1. Where is the cerebellum located? a. Extending from the rear of the brain stem 2. What is its size? a. Baseball 3. What does cerebellum mean? a. Little brain b. It is two halves 4. What does the cerebellum do? a. Involved in motor movement, enable nonverbal learning and skill memory,,, along with the help of the basal ganglia b. It helps us judge time, modulate our emotions and discriminate sounds and textures c. With the assistance of the PONS it coordinates voluntary movements 5. Example a. When a soccer player masterfully controls the ball, give the player’s cerebellum some credit. Under alcohol’s influence, coordination suffers. And if you injured your cerebellum, you would have difficulty walking, keeping your balance, or shaking hands. Your movements would be jerky and exaggerated. Gone would be any dreams of being a dancer or guitarist 6. What is the basal ganglia? 7. Where would the damage have to be for you to disrupt your ability to skip rope? a. Cerebellum b. Disrupt hearing? i. Thalamus c. Leave you in a coma? i. reticular formation d. Cut off the very breath and heartbeat of life? i. Medulla The Limbic system 1. What are the limbic system’s structures and functions? 2. What is the cerebral hemispheres? a. The newest and highest regions of the brain b. 2 halves 3. Where lies the limbic system? a. Between the oldest and newest brain areas 4. What does the limbic system mean? a. Limbus means border 5. What does the limbic system contain? a. The amygdala b. Hypothalamus c. Hippocampus 6. Figure 2.17 7. What does the limbic system’s hypothalamus control? a. The pituitary gland The Amygdala 1. What is the size of the amygdala? a. 2 lima bean sized neural cluster 2. What has the amygdala been linked to? a. Aggression and fear b. Is this present in anxiety and panic disorders? 3. Who are Heinrich Kluver and neurosurgeon Paul Bucy? a. psychologist Heinrich Klüver and neurosurgeon Paul Bucy surgically removed a rhesus monkey’s amygdala, turning the normally ill-tempered animal into the most mellow of creatures. In studies with other wild animals, including the lynx, wolverine, and wild rat, researchers noted the same effect. So, too, with human patients. Those with amygdala lesions often display reduced arousal to fear- and anger-arousing stimuli (Berntson et al., 2011). One such woman, patient S. M., has been called “the woman with no fear,” even if being threatened with a gun (Feinstein et al., 2013). 4. What year was this? a. 1939 5. What then might happen if we electrically stimulated the amygdala of a normally placid domestic animal, such as a cat? a. Do so in one spot and the cat prepares to attack, hissing with its back arched, its pupils dilated, its hair on end. Move the electrode only slightly within the amygdala, cage the cat with a small mouse, and now it cowers in terror. 6. One study found math anxiety associated with hyperactivity in the right amygdala 7. Monkeys and humans with amygdala damage become less fearful of strangers (Harrison et al., 2015). 8. Other studies link criminal behavior with amygdala dysfunction (Boccardi et al., 2011; Ermer et al., 2012). When people view angry and happy faces, only the angry ones increase activity in the amygdala 9. Why must we be careful about this? a. The brain is not neatly organized into structures that correspond to our behavior categories. When we feel afraid or act aggressively, there is neural activity in many areas of our brain—not just the amygdala. If you destroy a car’s battery, it’s true that you won’t be able to start the engine. But the battery is merely one link in an integrated system. 10. Electrical stimulation of a cat’s amygdala provokes angry reactions. Which autonomic nervous system division is activated by such stimulation? a. The sympathetic nervous system The Hypothalamus 1. Where is the hypothalamus located? a. Below the thalamus 2. What is the hypothalamus’s function? a. It is an important link in the common chain governing bodily maintenance. 3. What does the hypothalamus influence? a. Hunger, regulate thirst, body temperature, sexual behavior b. Maintain homeostasis 4. Where does the hypothalamus get its info? a. Tunes into blood chemistry and orders from the brain b. example: For example, picking up signals from your brain’s cerebral cortex that you are thinking about sex, your hypothalamus will secrete hormones. c. These hormones will in turn trigger the adjacent “master gland” of the endocrine system, your pituitary (see Figure 2.17), to influence your sex glands to release their hormones. These hormones will intensify the thoughts of sex in your cerebral cortex. (Note the interplay between the nervous and endocrine systems: The brain influences the endocrine system, which in turn influences the brain.) 5. What did James Olds and Peter Milner do? a. Two young McGill University neuropsychologists, James Olds and Peter Milner (1954), were trying to implant an electrode in a rat’s reticular formation when they made a magnificent mistake: They placed the electrode incorrectly (Olds, 1975). Curiously, as if seeking more stimulation, the rat kept returning to the location where it had been stimulated by this misplaced electrode. On discovering that they had actually placed the device in a region of the hypothalamus, Olds and Milner realized they had stumbled upon a brain center that provides pleasurable rewards (Olds, 1975). 6. What year did this happen? a. 1954 7. Why do scientists refer to REWARD CENTERS? a. Later experiments located other “pleasure centers” (Olds, 1958). (What the rats actually experience only they know, and they aren’t telling. Rather than attribute human feelings to rats, today’s scientists refer to reward centers, not “pleasure centers.”) Just how rewarding are these reward centers? Enough to cause rats to self-stimulate these brain regions more than 1000 times per hour. Moreover, they would even cross an electrified floor that a starving rat would not cross to reach food. 8. What was found in front of the rats?? 9. What was found in dolphins and monkeys? a. In other species, including dolphins and monkeys, researchers later discovered other limbic system reward centers, such as the nucleus accumbens in front of the hypothalamus (Hamid et al., 2016). A 10. What is the nucleus accumbens 11. Where tithe nucleus acumen? a. Infront of the hypothalamus 12. Animal research has also revealed both a general dopamine-related reward system and specific centers associated with the pleasures of eating, drinking, and sex. Animals, it seems, come equipped with built-in systems that reward activities essential to survival. 13. example:Researchers are experimenting with new ways of using brain stimulation to control nonhuman animals’ actions in search-and-rescue operations. By rewarding rats for turning left or right, one research team trained previously caged rats to navigate natural environments (Talwar et al., 2002). By pressing buttons on a laptop, the researchers were then able to direct the rat—which carried a receiver, power source, and video camera all in a tiny backpack—to turn on cue, climb trees, scurry along branches, and return 14. Do humans have limbic centers of pleasure? a. To calm violent patients, one neurosurgeon implanted electrodes in such areas. Stimulated patients reported mild pleasure; unlike Olds’ rats, however, they were not driven to a frenzy b. Moreover, newer research reveals that stimulating the brain’s “hedonic hotspots” (its reward circuits) produces more desire than pure enjoyment (Kringelbach & Berridge, 2012). Experiments have also revealed the effects of a dopamine-related reward system in people. For example, dopamine release produces our pleasurable “chills” response to a favorite piece of music 15. Where do researchers believe substance abuse issues stem from? a. Some researchers believe that substance use disorders may stem from malfunctions in natural brain systems for pleasure and well-being. 16. People genetically predisposed to this reward deficiency syndrome may crave whatever provides that missing pleasure or relieves negative feelings (Blum et al., 1996). 17. What is reward deficiency syndrome? a. Provides the missing pleasure or relieves negative feelings The Hippocampus 1. What is the shape of the hippocampus? a. Sea horse shaped brain structure 2. What is its function? a. Processes conscious, explicit memories and decrease in size and function as we grow older b. Humans who lose their hippocampus to surgery or injury also lose their ability to form new memories of facts and events (Clark & Maguire, 2016). Those who survive a hippocampal brain tumor in childhood struggle to remember new information in adulthood 3. What may happen to national football players? a. If they get a concussion they may have a reduced size of the hippocampus in the future b. And poor memory 4. What are the 3 key structures of the limbic system and their functions? a. Amygdala b. Hypothalamus c. Hippocampus i. Amygdala- involved in aggression and fear responses ii. Hypothalamus- bodily maintenance, pleasurable reward and control of hormonal systems iii. Hippocampus-processes memory of fact and event 5. How do neuroscientists study the brain’s connections to behavior and mind? a. Clinical observations and lesioning reveal effect of brain damage b. Electrical and chemical and magnetic stimulation gives information about processing in the brain c. EEG,MEG,PET, fMRI- reveals brain function 6. What structures make up the brainstem? a. Medullas b. Pons c. reticular formation d. thalamus 7. What are the functions of the brainstems, thalamus, reticular formation and cerebellum? a. Medulla-controls heartbeat and breathing b. Pons-coordinates movements and control sleep c. reticular formation-filters incoming stimuli, relays information to other brain areas and affects arousal d. Thalamus- sensory control center-top of brainstem e. Cerebellum- attached to the rear of the brainstem- coordinates muscles movement and balance and enable nonverbal learning and memory 8. What are the limbic system’s structures and functions? a. Linked to emotions, memory and drives b. Amygdala i. Involved in aggression and fear c. Hypothalamus-- THE MASTER GLAND i. Controls the pituitary gland by stimulating it to trigger release of hormones ii. Bodily maintenance functions iii. Governs the endocrine system iv. Linked to emotion and reward d. Hippocampus i. Processes explicit and conscious information and memories 9. The part of the brainstem that controls heartbeat and breathing is the a. Medulla 10. The thalamus functions as the? a. Sensory control center 11. The lower brain structure that govern arousal is the a. Reticular formation 12. The part of the brain that coordinates voluntary movement and enables nonverbal learning and memory is a. Cerebellum 13. 2 parts of the limbic system are the amygdala and the? a. Hippocampus 14. What controls eating, drinkin and body temp? a. Hypothalamus 15. The initial reward center discovered by olds and milner was located in the a. hypothalamus