1. Copyright © Allyn & Bacon 2007 Chapter 3 Biopsychology and the Foundations of Neuroscience This multimedia product and its contents are protected under copyright law. The following are prohibited by law: Any public performance or display, including transmission of any image over a network; Preparation of any derivative work, including the extraction, in whole or in part, of any images Any rental, lease or lending of the program. ISBN: 0-131-73180-7

2. Copyright © Allyn & Bacon 2007 Some Brain Facts… It is about the size of grapefruit 3 pounds, pinkish-gray, wrinkled surface 100 billion nerve cells, sometimes with up to 10,000 connections to other cells At birth the brain has extra nerve cells that die off; by adolescence that stabilizes and the total number is constant later on There is some loss and gain through adulthood, but by age 70 we end up with over 98%

3. Copyright © Allyn & Bacon 2007 What is Biopsychology? Biopsychology – The specialty in psychology that studies the interaction of biology, behavior, and the environment Neuroscience – Interdisciplinary field that focuses on the brain and its role in psychological processes

4. Copyright © Allyn & Bacon 2007 Evolution has fundamentally shaped psychological processes because it favors genetic variations that produce adaptive behavior How Are Genes and Behavior Linked?

5. Copyright © Allyn & Bacon 2007 How Are Genes and Behavior Linked? Innate – Inborn; present at birth; part of the organism’s biological heritage Evolution – The gradual process of biological change that occurs in a species as it adapts to its environment

6. Copyright © Allyn & Bacon 2007 Evolution and Natural Selection Natural selection – The driving force behind evolution, by which the environment “selects” the fittest organisms

7. Copyright © Allyn & Bacon 2007 How Natural Selection Works Environmental pressure (changes in the environment) Competition (for resources) Selection of fittest phenotype (from among a variety of phenotypes) Reproductive success (genotype corresponding to fittest phenotypes passed to next generation) Frequency of that genotype increases (in next generation)

8. Copyright © Allyn & Bacon 2007 Genes and Inheritance Genotype – An organism’s genetic makeup Phenotype – An organism’s observable physical characteristics

9. Copyright © Allyn & Bacon 2007 Genes and Inheritance Mutations – Genetic variations, which occur randomly, especially during the recombination of chromosomes in sexual reproduction

10. Copyright © Allyn & Bacon 2007 Chromosomes, Genes, and DNA DNA (deoxyribonucleic acid)– A long, complex molecule that encodes genetic characteristics Genes (they are like words in a sentence)– The functional units of a chromosome Composed of nucleotides—they are like the letters in words (A,G,T,C)

11. Copyright © Allyn & Bacon 2007 Sex chromosomes – The X and Y chromosomes that determine our physical sex characteristics Chromosomes, Genes, and DNA Chromosomes (like a string of words; they include punctuation and timing)– Tightly coiled threadlike structures along which the genes are organized

12. Copyright © Allyn & Bacon 2007 Genetic Explanations for Psychological Processes Genes influence our psychological characteristics as well as our physical traits—the complete package of human genes=30,000 There are 46 chromosomes; 23 pairs Multiple genes contribute to schizophrenia, Alzheimer’s disease; an extra chromosome 21 results in Down syndrome

13. Copyright © Allyn & Bacon 2007 The body’s two communication systems, the nervous system and the endocrine system, both use chemical messengers to communicate with targets throughout the body How Does the Body Communicate Internally?

14. Copyright © Allyn & Bacon 2007 The Neuron Types of Neurons Sensory neurons—afferent--(carry messages from sense receptors towards the CNS) Motor neurons—efferent--(carry messages from CNS toward muscles and glands) Interneurons (carry messages between nerve cells)

15. Copyright © Allyn & Bacon 2007 The Structure of a Neuron

16. Copyright © Allyn & Bacon 2007 The Neural Impulse Neural impulse – Brief electric surge that carries the neuron’s message Ions – Charged particles that are moved across the cell membrane

17. Copyright © Allyn & Bacon 2007 The Neural Impulse Resting potential—negative—when the cell is inactive and ready to fire Action potential—impulse caused in a fraction of second when the charge changes from negative to positive…this is done in an all or none manner Synapse—gap between neurons or neurons and muscles/glands Synaptic transmission—relaying information across the synapse by use of chemical neurotransmitters

18. Copyright © Allyn & Bacon 2007 Neurotransmitters Neurotransmitters – Chemical messengers that relay neural messages across the synapse

19. Copyright © Allyn & Bacon 2007 Seven Important Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins

20. Copyright © Allyn & Bacon 2007NeurotransmittersDopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Produces sensations of pleasure and reward; used by CNS neurons in voluntary movement Problems with Imbalance: Schizophrenia, Parkinson’s disease Substances that Affect: Cocaine, amphetamines, Ritalin, alcohol

21. Copyright © Allyn & Bacon 2007Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Regulates sleep and dreaming, mood, pain, aggression, appetite and sexual behavior Problems with Imbalance: Depression, certain anxiety disorders, obsessive- compulsive disorder Substances that Affect: Prozac, hallucinogenics (e.g. LSD)

22. Copyright © Allyn & Bacon 2007Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Controls heart rate, sleep, sexual responsiveness, stress, vigilance and appetite Problems with Imbalance: High blood pressure, depression Substances that Affect: Tricyclic antidepressants, beta blockers

23. Copyright © Allyn & Bacon 2007Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Primary transmitter used by neurons carrying messages from CNS; involved in some kinds of learning and memory Problems with Imbalance: Certain muscular disorders, Alzheimer’s disease Substances that Affect: Nicotine, botulism toxin, curare, atropine

24. Copyright © Allyn & Bacon 2007Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Most prevalent inhibitory neurotransmitter in neurons of CNS Problems with Imbalance: Anxiety, epilepsy Substances that Affect: Barbiturates, tranquilizers (e.g. Valium, Librium), alcohol

25. Copyright © Allyn & Bacon 2007Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Primary excitatory neurotransmitter in CNS; involved in learning and memory Problems with Imbalance: Brain damage after stroke Substances that Affect: PCP (“angel dust”)

26. Copyright © Allyn & Bacon 2007Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Pleasurable sensations and control of pain Problems with Imbalance: Lowered levels resulting from opiate addiction Substances that Affect: Opiates: opium, heroin, morphine, methadone

27. Copyright © Allyn & Bacon 2007 Plasticity Plasticity – Ability of the nervous system to adapt or change as the result of experience; sometimes helps the nervous system adapt to physical damage

28. Copyright © Allyn & Bacon 2007 Glial Cells Glial cells (from the Greek for “glue”) Provide structural support for neurons Help in forming new synapses Form myelin sheath MS (multiple sclerosis) attacks the myelin sheath resulting in poor conduction and loss of movement control

29. Copyright © Allyn & Bacon 2007 The Organization of the Nervous System Nervous system Peripheral nervous system Central nervous system (CNS) Autonomic nervous system Somatic nervous system— splits into sensory and motor NS Sympathetic nervous system Parasympathetic nervous system

30. Copyright © Allyn & Bacon 2007 The Endocrine System (the body’s chemical messenger system)

31. Copyright © Allyn & Bacon 2007 The Endocrine System Pituitary gland – Master gland that produces hormones influencing the secretions of all other endocrine glands; produces hormone that influences growth; attached to hypothalamus

32. Copyright © Allyn & Bacon 2007 How Does the Brain Produce Behavior and Mental Processes? The brain is composed of many specialized modules that work together to create mind and behavior

33. Copyright © Allyn & Bacon 2007 Windows on the Brain EEG (electroencephalograph) – Device for recording brain waves, typically by electrodes placed on the scalp Brain waves – Patterns of electrical activity generated by the brain

34. Copyright © Allyn & Bacon 2007 Windows on the Brain Epilepsy – Brain disorder that is often marked by seizures and loss of consciousness; caused by out-of-control electrical activity in the brain

35. Copyright © Allyn & Bacon 2007 Windows on the Brain Lesions – Tissue damage that results from disease or injury

36. Copyright © Allyn & Bacon 2007 Windows on the Brain Brain scans – Recordings of the brain’s electrical or biochemical activity at specific sites CT scanning (computerized tomography) X rays are passed through at various angles creating a static image of brain structure PET scanning (positron emission tomography) senses low-level radioactive glucose to create brightly colored areas of activity MRI (magnetic resonance imaging) also functional or fMRI creates highly detailed pictures from pulses of magnetic energy

37. Copyright © Allyn & Bacon 2007 Three Layers of the Brain Brain stem and cerebellum Drive vital functions, such as heart rate, breathing, digestion Limbic system Adds emotions, complex motives, increased memory abilities Cerebrum Enables reasoning, planning, creating, problem solving

38. Copyright © Allyn & Bacon 2007 The Brain Stem and Cerebellum Thalamus Pons Cerebellum Medulla Brain stem

39. Copyright © Allyn & Bacon 2007 The Limbic System Hypothalamus – Serves as the brain’s blood- testing laboratory, constantly monitors blood to determine the condition of the body

40. Copyright © Allyn & Bacon 2007 The Limbic System Amygdala – Involved in memory and emotion, particularly fear and aggression

41. Copyright © Allyn & Bacon 2007 The Limbic System Hippocampus – Involved in establishing long-term memories

42. Copyright © Allyn & Bacon 2007 The Cerebrum Cerebrum – Topmost layer of the brain; the bulbous cap over the limbic system Cerebral cortex – Thin gray-matter covering of the cerebrum; carries on thinking and perceiving=2/3 of brain’s total mass Cerebral hemispheres – The two walnut shaped halves of the cerebrum, connected by the corpus callosum

43. Copyright © Allyn & Bacon 2007 The Four Lobes of the Cerebral Cortex Frontal lobes (movement…motor cortex, planning, deciding, perceiving) Parietal lobes (touch sensation…somatosensory cortex and spatial relationships) Occipital lobes (contain visual cortex) Temporal lobes (process sounds/speech and has some ties to memory)

44. Copyright © Allyn & Bacon 2007 The Cooperative Brain Association cortex – Cortical regions that combine information from various other parts of the brain

45. Copyright © Allyn & Bacon 2007 Cerebral Dominance Cerebral dominance – Tendency of each brain hemisphere to exert control over different functions Aphasia – The loss of speech caused by brain damage Speech production lies in the frontal lobe, left hemisphere (Broca’s area. Understanding language lies in the left parietal and temporal lobes (Wernicke’s area). Spatial orientation – Process of locating one’s body or other objects in space

46. Copyright © Allyn & Bacon 2007 Specialization of the Cerebral Hemispheres Left Hemisphere Right Hemisphere Spontaneous speaking and writing Responses to complex commands Word recognition Memory for words and numbers Sequences of movements Positive emotion Repetitive but not spontaneous speaking Responses to simple commands Facial recognition Memory for shapes and music Spatial interpretation Emotional responsiveness Negative emotion

47. Copyright © Allyn & Bacon 2007 The Split Brain Split-brain patients – Individuals who have had the corpus callosum surgically severed Duality of consciousness – Condition in which a split-brain patient has a separate consciousness in each hemisphere

48. Copyright © Allyn & Bacon 2007 End of Chapter 3