Chapter 6


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The Brain

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Chapter 6

  1. 1. The Workings of the Mind and Body
  2. 2.  Nervous system controls your emotions, movement, thinking and behavior 2 parts:  central nervous system (CNS)- the brain and spinal cord  peripheral nervous system (PNS)-consists of smaller branches of nerves that reach other parts of the body
  4. 4.  Long, thin cells of nerve tissue that send messages to and from the brain; they fire on an “all-or-nothing” principle Parts of a neuron- cell body, dendrites, axon  Cell body-nucleus; produces energy to fuel activity  Dendrites-short, thin fibers that receive impulses  Axon- long fiber that carries impulses towards the dendrites of the next neuron
  5. 5. Will Explain Why We FEEL…… Strong NervousPain Sick
  6. 6. Neuron StructureNeurons do NOT touch each other- thespace in between is call the synapse.
  7. 7.  Neurons transmits impulses by releasing chemicals- neurotransmitters that excite or inhibit  Norepinephrin- involved with memory and learning (undersupply = depression)  Endorphin- inhibits pain  Ecetylcholine- movement and memory (paralysis and Alzheimer’s)  Dopamine- involved in learning, emotional arousal, and movement (oversupply = schizophrenia, undersupply = Parkinson’s)
  8. 8. Its function is motor movement and maybe memory. To much and you will…. Not enough and you will….Lack of ACH has been linked to Alzheimer’s disease.
  9. 9. Its function is motor movement and alertness.Lack of dopamine is associated withParkinson’s disease.Overabundance is associated withschizophrenia.
  10. 10. Function deals with pain control.We become addicted to endorphin causingfeelings.
  11. 11. Function deals with mood control.Lack of serotoninhas been linked todepression.
  12. 12. It is an electrochemical processElectrical inside the neuronChemical outside the neuron (in the synapse in the form of a neurotransmitter).The firing is call Action Potential.
  13. 13.  The idea that either the neuron fires or it does not- no part way firing. Like a gun
  14. 14. How Neurons Communicate
  15. 15. Sensory Neurons Motor Neurons Inter Neurons
  16. 16. Take information from the senses to the brain.
  17. 17. Take information from brain to the rest of the body.
  18. 18.  Takemessages from Sensory Neurons to other parts of the brain or to Motor Neurons.
  19. 19. Divisions of the Nervous System
  20. 20.  Somatic nervous system (SNS)- controls voluntary activities- movement of skeletal muscles
  21. 21.  Autonomic nervous system (ANS)- controls involuntary activities such as heartbeat and stomach activity  Sypathetic N.S.- “fight or flight”
  22. 22. Flight or Fight Response - prepares body for dealing with emergencies or strenuous activity
  23. 23.  works to conserve energy and enhance the body’s ability to recover from strenuous activity
  24. 24. A Simple Reflex
  25. 25. A Simplified Neural Network as a team.Neurons that learn to work together
  26. 26.  Accidents Lesions CAT Scan PET Scan MRI Functional MRI
  27. 27.  Hindbrain- rear base of skull; most basic processes of life  Cerebellum- helps control posture, balance and voluntary movements  Medulla- breathing, heart rate and reflexes  The pons- bridge between spinal cord and brain; produces chemicals for sleep Midbrain- small part above the pons; integrates sensory info and relays it upward  RAS- reticular activation system- alerts the rest of brain to incoming signals
  28. 28.  Cerebrum consists of 2 hemispheres connected by a band of fibers- corpus callosum Cerebral cortex is divided into 4 lobes  Occipital lobe- processes visual signals  Parietal lobe- processes info from senses from all over the body  Temporal lobe- hearing, memory, emotion and speaking  Frontal lobe- organization, planning and creative thinking Somatosensory cortex- receives info from touch sensors Motor cortex- controls fine movement
  29. 29. 1. Hindbrain2. Midbrain3. Forebrain -Cerebral Cortex (part or forebrain)
  30. 30. Structures on top of our spinal cord. Controls basic biological structures. The brain in purple makes up the hindbrain.
  31. 31.  Located just above the spinal cord.Involved in control of blood pressure heart rate Breathing Reflexes
  32. 32.  Located just above the medulla. Connects hindbrain with midbrain and forebrain. Involved in facial expressions, produces chemicals for sleep
  33. 33.  Bottom rear of the brain. “little brain” Coordinates fine muscle movements – posture, balance
  34. 34. If stimulated Coordinates simple movements with sensory information - RAS- reticular activation system- alerts the rest of brain to incoming signals controls arousal and ability to focus our attention (important!) If Destroyed
  35. 35.  What makes us human. Largest part of the brain – central core.
  36. 36.  Maybe most important structure in the brain. Controls and regulates  Body temperature  Sexual ArousalThe most powerful structure in the brain.  Hunger  Thirst  Endocrine System
  37. 37.  Switchboard of the brain. Receives sensory signals from the spinal cord and sends them to other parts of the forebrain. Every sense except smell.
  38. 38.  Made up of densely packed neurons we call “gray matter” Glial Cells: support brain cells. Wrinkles are called fissures. outer layer; ability to learn and store complex and abstract info and to project thinking into the future
  39. 39. The Cerebral Cortex is made up of four Lobes.
  40. 40.  Abstract thought and emotional control. Contains Motor Cortex: sends signals to our body controlling muscle movements. Contains Broca’s Area: responsible for controlling muscles that produce speech. Damage to Broca’s Area is called Broca’s Aphasia: unable to make movements to talk.
  41. 41. Motor and Sensory Cortexes
  42. 42.  Contain Sensory Cortex: receives incoming touch sensations from rest of the body.  Most of the ParietalWhere would this girl feel the mostpain from her sunburn? Lobes are made up of Association Areas.
  43. 43.  Any area not associated with receiving sensory information or coordinating muscle movements.
  44. 44. Motor and Sensory Cortexes
  45. 45.  Deals with vision. Contains Visual Cortex: interprets messages from our eyes into images we can understand.
  46. 46.  Process sound sensed by our ears. Interpreted in Auditory Cortex. NOT LATERALIZED. Contains Wernikes Area: interprets written and spoken speech. Wernikes Aphasia: unable to understand language: the syntax
  47. 47. Specialization and Integration in Language
  48. 48. Brain Activity when Hearing, Seeing, and Speaking Words
  49. 49. The Limbic System
  50. 50.  Involvedin the processing and storage of memories.
  51. 51.  Involved in how we process memory. More involved in volatile emotions like anger. The emotion of anger has not changed much throughout evolution.
  52. 52. Pituitary Gland •“master gland” •Key hormone is the growth hormone. •Overproduction may result in gigantism.•Major growth in hands, feet, and chin.
  53. 53. Divides the 2hemispheres.
  54. 54. Divided into to hemispheres. Contralateral control: right controls left and vice versa.In general,Left Hemisphere: logic and sequential tasks.Right Hemisphere: spatial and creative tasks.
  55. 55.  The idea that the brain, when damaged, will attempt to find news ways to reroute messages. Children’s brains are more plastic than adults.
  56. 56. Left hemisphere Right hemisphere Controls right side of  Controls left side of body body Verbal  Nonverbal Mathematical  Spatial/visual Analytical  Holistic logic  Perception, patterns  Creativity/intuition
  57. 57. •19 men and 19 women asked to determine if two nonsense words rhymed.•All 19 men had left frontal lobe light up•11 of 19 women had that plus lighting behind right eyebrow•Left brain (reason) Right brain (feelings)•Thus women draw on feelings as well as reason when they use words.
  58. 58. University of Pennsylvania•37 men and 24 women told to think of nothing while linked to a PETmachine•Men-reported being fixated on sex and football•Women-fixated on stringing words together, such as “How muchlonger?”, “Why are we doing this?”
  59. 59. Found that the women’s corpus callosum to be 23% larger thanmen’s. This may be the reason for more hemispheric chit chat. Alsomay help explain why women have better intuition.
  60. 60. Baby’s BrainGenetics make up basic wiring ofthe brain. Experience makes upthe majority. “Live” languageboostsvocabulary. The downside to a baby’s brain is that it is very vulnerable to trauma.Stress produces a hormone called cortisol, which acts like an acid on the brain.
  61. 61. Those who dues to epilepsy,have their corpus callosumremoved.
  62. 62.  The 2 hemispheres communicate through the corpus callosum Sometimes necessary to disconnect the 2 sides- severe seizures Split brain people have difficulty verbalizing objects in the left hand Injuries to the specific areas of the brain cause personality changes, emotional changes, speech and memory issues, etc.
  63. 63. Testing the Divided Brain
  64. 64. Decreasing Left-handers
  65. 65.  Phineas Gage- railroad foreman had temping iron puncture his skull; changed his personality- more aggressive Lesions- experiments with animals; destroying temporal lobe in rhesus monkeys gave them violent tendencies Broca’s area- left side of cortex was damaged in his patient- could not produce speech
  66. 66.  Electroencephalograph (EEG)- machine used to record electrical activity of the brain Computerized axial tomography (CAT)- uses x-ray beams (radiation) to study the brain to pinpoint injuries and brain deterioration Positron emission tomography (PET)- uses radioactive solution to see which brain areas are activated while performing tasks Magnetic resonance imaging (MRI)- passes non- harmful radio frequencies through the brain to study structure and activity FMRI- functional MRI uses blood oxygen level
  67. 67. A system of glands that secretehormones.Similar to nervous system, excepthormones work a lot slower thanneurotransmitters. Hormones Neurotransmitters
  68. 68. The Major Endocrine Glands
  69. 69.  Sends chemical messages (hormones) to and from the brain Hormones- chemical substances - carry messages through the body in blood; -growth of muscles and bones, metabolic processes, energy, moods, and drives
  70. 70. Neurotransmitters - Send rapid and specific messagesHormones - Send slow, widespread communication
  71. 71.  Nature v. nurture Flower analogy- genes establish what you could be and environment defines the final product Studies done on identical twins raised apart help to show how much of our personality is from genetics and from environment
  72. 72.  Consciousness- a state of awareness Sleep CyclesStage 1- pulse slows, irregular brain wave activity; drifting; approx. 10 minutesStage 2- high amplitude, low frequency wavesStage 3- after 30 minutes; large amplitude delta wavesStage 4- deepest sleep; large delta waves75% of sleep time is spent in stages 1-4REM sleep- rapid eye movement; high level of brain activity with deep relaxation of muscles and dreams; lasts 15-45 minutes; run through cycles every 90 minutes
  73. 73.  Circadian rhythm- biological clock genetically programmed to regulate physiological responses within 24 hours How much sleep do you need?  Newborns- 16 hrs  Teens- 10-11 hrs  College age- 8 hrs  70 year olds- 5 hours Lucid dreaming- you are aware that you are dreaming; day dreaming
  74. 74. Insomnia Sleep apnea Narcolepsy Nightmares Night terrors Sleep- walkingFailure to get Person has Sudden Unpleasant Sleep Walking orenough sleep trouble falling asleep dreams disruptions carrying out breathing or feeling during REM during stage 4 behaviors while asleep; sleepy during sleep; vivid involving while affects 1 in the day dreams screaming, sleeping; no 100 panic or memory of Americans confusion; no doing so memory of night terrorCauses- Causes- Causes-anxiety, enlarged stress,depression, tonsils, fatigue,alcohol or infections of sedativedrug abuse throat/middle medicines, ear, obesity genetics
  75. 75.  Hypnosis- altered consciousness due to narrowed focus; people are highly suggestible to changes in behavior and thought Franz Anton Mesmer- 1st hypnotist Neodissociation theory- “hidden observer” part of the personality watches and reports what happens to the hypnotized person
  76. 76.  Posthypnotic suggestion- a suggestion made during hypnosis that influences behavior afterward; helpful with unwanted behaviors such as smoking and over eating Hypnotic analgesia- hypnosis used to reduce pain Biofeedback- learning to control bodily states with the help of monitoring machines; control brainwaves, heart rate, blood pressure, skin temperature; feedback makes learning possible
  77. 77.  Meditation- focusing attention to clear one’s mind and produce relaxation Transcendental meditation- mental repetition of a mantra; eyes closed 15-20 minutes a day Mindful meditation- Buddhist tradition; focus on present movement Breath meditation- concentration on inhaling and exhaling Meditation has been found to help lower blood pressure, heart rate and respiration rate
  78. 78.  How drugs work-  Carried by the blood, work like neurotransmitters at the end of nerve cells to send their own messages Psychoactive drugs- interact with nervous system and alter consciousness, mood, perception & behavior (caffeine, alcohol, marijuana, LSD)
  79. 79.  Marijuana- most often used illegal drug  THC- active ingredient  Effects vary from person to person- intensifies sensory experiences, distorts perception of time, intensifies unpleasant feelings, impairs learning, disrupts memory formation  Psychologically addicting  Causes lung damage
  80. 80.  Hallucinations- perceptions that have no direct external cause Hallucinogens/psychedelics- drugs that often produce hallucinations; create a loss of contact with reality (LSD) Opiates/narcotics (opium, morphine, heroin); they produce analgesia- pain reduction, euphoria and constipation; leads to physical addiction; overdose results in loss of control of breathing Alcohol- most widely used/abused drug; depressant that inhibits brain’s normal functions
  81. 81. Drug category examples effects Negative effectsstimulants Nicotine, caffeine, Increases alertness Anxiety, restlessness, amphetamines, and energy, irritability, crystal meth excitation, euphoria, sleeplessness, confidence aggressiveness, feelings of panicdepressants alcohol Relaxation Relieves inhibitions; impairs memory and judgmenttranquilizers Valium, Xanax, Relieves anxiety, Impaired barbiturates relaxes muscles, coordination, induces sleep depression, lethargy, drowsinessopiates/narcotics Morphine, heroin, Euphoria, less Lethargy, nausea, opium, codeine, sensitivity to pain, impaired vicodin coordination, unpleasant withdrawal effectshallucinogens LSD, mescaline Euphoria, changed Nausea, paranoia, perception, insightful panic, jumbled moments thoughts
  82. 82.  Why do people abuse drugs? What are the dangers? How can we treat drug abuse? How can we prevent drug use?
  83. 83.  Stimulus- any aspect of or change in the environment to which an organism responds Sensation- what occurs when a stimulus activates a receptor Perception- the organization of sensory information into meaningful experiences Psychophysics- the study of the relationship between stimuli and sensory experiences
  84. 84.  Absolute threshold- the weakest amount of a stimulus required to produce a sensation Difference threshold- smallest change in a physical stimulus that can be detected between two stimuli Just Noticeable Difference (JND)- smallest increase or decrease in the intensity of a stimulus that a person is able to detect Weber’s Law- the larger or stronger a stimulus, the larger the change required for a person to notice
  85. 85.  Signal-detection theory- humans can choose what stimuli to attend to and block out surrounding stimuli Sensory adaptation- we respond to and adapt to changes in our environment The Stroop Effect-
  86. 86.  7 senses- vision, hearing, taste, smell, touch, vestibular (balance) & kinesthetic (movement & body position)
  87. 87.  Objects look the color of light they reflect; they absorb all other light colors Blind spot- where optic nerve exits the eye Color deficient- when cones don’t function properly Binocular vision- combining images from each eye into a single image Retinal disparity- the differences between the images which is essential to depth perception Near sightedness and far sightedness
  88. 88.  Loudness- determined by amplitude (height of wave) Decibel- measure of loudness (sound pressure energy) Pitch- depends on frequency Deafness- 2 types  Conduction-problems with outer or middle ear when physical motion is hindered; can be helped with hearing aids  Sensorineural- damage to cochlea, hair cells, or neurons
  89. 89.  Regulated by vestibular system in the inner ear (fluid) 3 semicircular canals Stimuli for responses- spinning, falling, tilting head
  90. 90.  Gaseous molecules must come into contact with smell receptors in nose Olfactory nerve carries impulses from nose to the brain
  91. 91.  Liquid chemicals stimulate taste bud receptors 4 senses  Sour  Salty  Bitter  Sweet Flavor is a combination of taste, smell and tactile sensations
  92. 92.  Receptors responsible for info about pressure, warmth, cold & pain 2 kinds of pain  Sharp and localized  Dull and generalized Gate control theory of pain- can lessen pain by shifting attention away from pain impulses or by sending competing signals
  93. 93.  Sense of movement and body position Receptors in muscles, tendons, and joints It coordinates movement
  94. 94.  Gestalt- organizing bits & pieces of information into meaningful wholes  Proximity Similarity  Closure Continuity  simplicity
  95. 95.  Figure-ground perception- ability to discriminate between a figure and its background Perceptual inference- filling in gaps in what our senses tell us Subliminal messages- brief auditory or visual messages presented below the absolute threshold
  96. 96.  Motion parallax- the apparent movement of stationary objects relative to one another that occurs when the observer changes position Constancy- tendency to perceive objects in the same way regardless of changing angle, distance, or lighting Illusions- perceptions that misrepresent physical stimuli Extra sensory perception (ESP)- ability to gain information by some means other than ordinary senses