1. Copyright McGraw-Hill, Inc. 2010 1 Chapter 2 The Brain and Behavior

2. Copyright McGraw-Hill, Inc. 2010 2 Chapter Preview The Nervous System Neurons Structures of the Brain and Their Functions The Endocrine System Brain Damage, Plasticity, and Repair Genetics and Behavior

3. Copyright McGraw-Hill, Inc. 2010 3 Nervous System Electrochemical communication circuitry Billions of interconnected cells Neuroscience Neuroscientists

4. Copyright McGraw-Hill, Inc. 2010 4 Nervous System: Characteristics Complexity Integration Adaptability Plasticity Electrochemical Transmission

5. Copyright McGraw-Hill, Inc. 2010 5 Nervous System: Pathways Afferent Nerves Sensory nerves Information to brain and spinal cord Efferent Nerves Motor nerves Information out of brain and spinal cord Neural Networks Integration of sensory input and motor output

6. Copyright McGraw-Hill, Inc. 2010 6 Nervous System: Divisions

7. Copyright McGraw-Hill, Inc. 2010 7 Nervous System: Primary Divisions Central Nervous System (CNS) Brain and Spinal Cord Peripheral Nervous System (PNS) Network of nerves connecting CNS to body Two subdivisions: Somatic Nervous System Autonomic Nervous System

8. Copyright McGraw-Hill, Inc. 2010 8 Nervous System: PNS Divisions Somatic Nervous System Sensory information from skin and muscles to CNS Autonomic Nervous System Messages to and from internal organs Two subdivisions: Sympathetic Nervous System  arousing Parasympathetic Nervous System  calming

9. Copyright McGraw-Hill, Inc. 2010 9 Nervous System: Stress “Fight or Flight” Reaction Function of sympathetic nervous system Corticosteroids Stress hormones Acute stress is momentary. Chronic stress is continuous.

10. Copyright McGraw-Hill, Inc. 2010 10 Nervous System: Cells Neurons Nerve cells Information processing Glial cells Support Nutritional benefits

11. Copyright McGraw-Hill, Inc. 2010 11 Neurons: Structure Cell Body Contains nucleus Dendrites Fibers projecting from neuron Axon Carries information from cell body toward other cells Myelin Sheath Layer of fat cells, encasing and insulating most axons

12. Copyright McGraw-Hill, Inc. 2010 12 Neurons: Structure

13. Copyright McGraw-Hill, Inc. 2010 13 Neural Impulse Resting potential Stable, negative charge of inactive neuron

14. Copyright McGraw-Hill, Inc. 2010 14 Neural Impulse Action Potential Brief, positive electrical charge, or firing Abides by the all-or-nothing principle

15. Copyright McGraw-Hill, Inc. 2010 15 Synapses & Neurotransmitters Synapses Space between neurons (synaptic gap) Neurotransmitters Stored in synaptic vesicles (sacs) within terminal buttons Chemical signals which allow electrical impulses to cross synaptic gaps

16. Copyright McGraw-Hill, Inc. 2010 16 Synapses & Neurotransmitters

17. Copyright McGraw-Hill, Inc. 2010 17 Neurochemical Messengers Neurotransmitters are excitatory, inhibitory, or both. Acetylcholine (ACh) Stimulates firing of neurons Involved in action of muscles, learning, memory Alzheimer disease: ACh deficiency Gamma aminobutyric acid (GABA) Keeps many neurons from firing Anxiety: Low levels of GABA

18. Copyright McGraw-Hill, Inc. 2010 18 Neurochemical Messengers Norepinephrine Inhibits firing of neurons in CNS Excites heart muscle, intestines, urogenital tract Depression: Too little norepinephrine Agitated, manic states: Too much norepinephrine Dopamine Helps to control voluntary movement Affects sleep, mood, attention, learning, rewards Parkinson disease: Low levels of dopamine Schizophrenia: High levels of dopamine

19. Copyright McGraw-Hill, Inc. 2010 19 Neurochemical Messengers Serotonin Involved in regulation of sleep, mood, attention, learning Depression: Lowered levels of serotonin Endorphins Natural opiates that mainly stimulate firing of neurons Shield body from pain Elevate feelings of pleasure Oxytocin Hormone and neurotransmitter Important role in experience of love and social bonding

20. Copyright McGraw-Hill, Inc. 2010 20 Drugs & Neurotransmitters Drugs influence behavior mainly by interfering with neurotransmitters. Agonist Drug that mimics or increases effects of neurotransmitter Antagonist Drug that blocks effects of neurotransmitter

21. Copyright McGraw-Hill, Inc. 2010 21 Neural Networks

22. Copyright McGraw-Hill, Inc. 2010 22 Studying the Brain Brain Lesioning Determines effects of brain tissue disruption on behaviors Staining Dyes neurons for tracking neural impulses Electrical Recording Detects brain wave activity

23. Copyright McGraw-Hill, Inc. 2010 23 Brain Imaging X-ray  two-dimensional images CT (or CAT) scan  three-dimensional images PET scan  metabolic changes MRI  brain structure f MRI  brain function

24. Copyright McGraw-Hill, Inc. 2010 24 Organization of the Brain Hindbrain Adjacent to top part of spinal cord Midbrain Rises above hindbrain Forebrain Uppermost region of brain

25. Copyright McGraw-Hill, Inc. 2010 25 Organization of the Brain

26. Copyright McGraw-Hill, Inc. 2010 26 Hindbrain Medulla Controls vital functions, such as breathing and heart rate Regulates reflexes Cerebellum Plays important role in motor coordination Pons Involved in sleep and arousal

27. Copyright McGraw-Hill, Inc. 2010 27 Midbrain Brain stem Includes much of hindbrain (but not cerebellum) and midbrain Determines alertness Regulates basic survival functions Reticular Formation Involved in stereotyped patterns of behavior, such as walking and sleeping

28. Copyright McGraw-Hill, Inc. 2010 28 Forebrain Limbic System Thalamus Basal Ganglia Hypothalamus Cerebral Cortex

29. Copyright McGraw-Hill, Inc. 2010 29 Forebrain: Limbic System Important in both memory and emotion Two principal structures Amygdala Involved in discrimination of objects necessary for survival Hippocampus Has special role in storage of memories

30. Copyright McGraw-Hill, Inc. 2010 30 Forebrain: Thalamus & Basal Ganglia Thalamus Serves as relay station for information Basal Ganglia Works with cerebellum and cerebral cortex to control and coordinate voluntary movements

31. Copyright McGraw-Hill, Inc. 2010 31 Forebrain: Hypothalamus Monitors... eating, drinking, sex emotion, stress, reward Helps direct endocrine system Regulator of body’s internal state Involved in pleasurable feelings

32. Copyright McGraw-Hill, Inc. 2010 32 Forebrain: Cerebral Cortex Occipital lobes Responding to visual stimuli Temporal lobes Hearing, language processing, memory Frontal lobes Personality, intelligence, control of voluntary muscles Parietal lobes Registering spatial location, attention, motor control

33. Copyright McGraw-Hill, Inc. 2010 33 Forebrain: Cerebral Cortex Somatosensory Cortex Located at front of parietal lobes Processes information about body sensations Motor Cortex Located just behind frontal lobes Processes information about voluntary movement Association Cortex Makes up 75% of cerebral cortex Integrates information

34. Copyright McGraw-Hill, Inc. 2010 34 Forebrain: Cerebral Cortex

35. Copyright McGraw-Hill, Inc. 2010 35 Cerebral Hemispheres Corpus Callosum Large bundle of axons connecting brain’s two hemispheres Relays information between two sides Left Hemisphere Receives information from right side of body Language processing, such as speech and grammar Right Hemisphere Receives information from left side of body Processing non-verbal information, such as spatial perception, visual recognition, and emotion

36. Copyright McGraw-Hill, Inc. 2010 36 Cerebral Hemispheres

37. Copyright McGraw-Hill, Inc. 2010 37 Endocrine System Set of glands that regulate activities of certain organs Glands Organs or tissues that create chemicals that control bodily functions Hormones Chemical messengers produced by endocrine glands

38. Copyright McGraw-Hill, Inc. 2010 38 Endocrine System Pituitary Gland Controls growth and regulates other glands Thyroid & Parathyroid Glands Adrenal Glands Regulate mood, energy level, and ability to cope with stress Pancreas Performs both digestive and endocrine functions Ovaries (in women) & Testes (in men) Produce hormones related to sexual development and reproduction

39. Copyright McGraw-Hill, Inc. 2010 39 Brain Damage, Plasticity, and Repair Collateral Sprouting Axons of healthy neurons adjacent to damaged cells grow new branches. Substitution of Function Damaged region’s function is taken over by another brain area. Neurogenesis New neurons are generated.

40. Copyright McGraw-Hill, Inc. 2010 40 Brain Tissue Implants Brain grafts Implants of healthy tissue into damaged brains Stem cells Primitive cells with capacity to develop into most types of human cells

41. Copyright McGraw-Hill, Inc. 2010 41 Genetics and Behavior Chromosomes Threadlike structures containing DNA DNA (deoxyribonucleic acid) Complex molecule that carries genetic information Genes Units of hereditary information

42. Copyright McGraw-Hill, Inc. 2010 42 Genetics and Behavior

43. Copyright McGraw-Hill, Inc. 2010 43 The Study of Genetics Dominant-Recessive Genes Principle If one gene in pair is dominant and one is recessive, dominant gene overrides recessive gene. Polygenic Inheritance Influence of multiple genes on behavior

44. Copyright McGraw-Hill, Inc. 2010 44 The Study of Genetics Molecular Genetics Manipulation of genes using technology to determine their effect on behavior Genome Complete set of genetic instructions for making an organism Human Genome Project International research program mapping human genome

45. Copyright McGraw-Hill, Inc. 2010 45 The Study of Genetics Selective Breeding Genetic method use to demonstrate importance of genetic influence on behavior Behavior Genetics Study of degree and nature of heredity’s influence on behavior Twin Studies Identical vs. Fraternal Twins Minnesota Study of Twins Reared Apart (1996)

46. Copyright McGraw-Hill, Inc. 2010 46 Genes and the Environment Genotype Genetic heritage Phenotype Observable characteristics Influenced by genotype and environmental factors Genetic Expression Activity of genes is affected by their environment.