1. Chapter 3
Brain and Behavior

2. Key Questions How do nerve cells operate and communicate?
What are the functions of major parts of the nervous systems?
How is the brain organized and what do its higher structure do?
Why are the brain’s association areas important? What happens when they are injured?
What kinds of behaviors are controlled by the subcortex?
Does the glandular system affect behavior?
In what ways do right-and left—handed individuals differ?
How do biopsychologists study the brain?

3. Neuron and Its Parts
Neuron: Individual nerve cell; 100 billion in brain
Dendrites: Receive messages from other neurons
Soma: Cell body; body of the neuron. Receives messages and sends messages down axon
Axon: Carries information away from the cell body
Axon Terminals: Branches that link the dendrites and somas of other neurons

4. Fig. 2.1 An example of a neuron, or nerve cell, showing several of its important features. The right foreground shows a nerve cell fiber in cross section, and the upper left inset gives a more realistic picture of the shape of neurons. The nerve impulse usually travels from the dendrites and soma to the branching ends of the axon. The neuron shown here is a motor neuron. Motor neurons originate in the brain or spinal cord and send their axons to the muscles or glands of the body.

5. Fig. 2.2 Activity in an axon can be measured by placing electrical probes inside and outside the axon. (The scale is exaggerated here. Such measurements require ultra-small electrodes, as described later in this chapter.) At rest, the inside of an axon is about –60 to –70 millivolts, compared with the outside. Electrochemical changes in a nerve cell generate an action potential. When positively charged sodium ions (Na+) rush into the cell, its interior briefly becomes positive. This is the action potential. After the action potential, an outward flow of positive potassium ions (K+) restores the negative charge inside the axon. (See Figure 2.3 for further explanation.)

6. Fig. 2. 5 A highly magnified view of the synapse shown in Fig. 2. 1
Fig. 2.5 A highly magnified view of the synapse shown in Fig Neurotransmitters are stored in tiny sacs called synaptic vesicles. When a nerve impulse arrives at an axon terminal, the vesicles move to the surface and release neurotransmitters. These transmitter molecules cross the synaptic gap to affect the next neuron. The size of the gap is exaggerated here; it is actually only about one millionth of an inch. Transmitter molecules vary in their effects: Some excite the next neuron and some inhibit its activity.

7. The Nerve Impulse
Resting Potential: Electrical charge of an inactive neuron
Threshold: Trigger point for a neuron’s firing
Action Potential: Nerve impulse
Ion Channels: Axon membrane has these tiny holes or tunnels
Negative After-Potential: When a neuron is less willing to fire

8. Fig. 2.3 The inside of an axon normally has a negative electrical charge. The fluid surrounding an axon is normally positive. As an action potential passes along the axon, these charges reverse, so that the interior of the axon briefly becomes positive.

9. Fig. 2. 4 Cross-sectional views of an axon
Fig. 2.4 Cross-sectional views of an axon. The right end of the top axon is at rest, with a negatively charged interior. An action potential begins when the ion channels open and sodium ions (Na+) enter the axon. In this drawing the action potential would travel rapidly along the axon, from left to right. In the lower axon the action potential has moved to the right. After it passes, potassium ions (K+) flow out of the axon. This quickly renews the negative charge inside the axon, so it can fire again. Sodium ions that enter the axon during an action potential are pumped back out more slowly. Their removal restores the original resting potential.

10. Animation: Neuron & Neural Impulse

11. Synapses and Neurotransmitters
Synapse: The microscopic space between two neurons, over with messages pass
Neurotransmitters: Chemicals that alter activity in neurons; brain chemicals
Acetylcholine: Activates muscles
Dopamine: Muscle control
Serotonin: Mood and appetite control
Messages from one neuron to another pass over a microscopic gap called a synapse
Receptor Site: Areas on the surface of neurons and other cells that are sensitive to neurotransmitters

12. Animation: Synaptic Transmission

13. Neural Regulators Neuropeptides: Regulate activity of other neurons
Enkephalins: Relieve pain and stress; similar to endorphins
Endorphins: Released by pituitary gland; also help to relieve pain
Placebos raise endorphin levels

14. The Nervous System- Wired for Action
Nerves and Neurons
Nerves: Large bundles of axons and dendrites
Myelin: Fatty layer that coats some axons
Multiple Sclerosis (MS) occurs when myelin layer is destroyed; numbness, weakness, and paralysis occur
Neurilemma: Thin layer of cells wrapped around axons outside brain and spinal cord; forms a tunnel that damaged fibers follow as they repair themselves

15. Brain Grafts and Nerve Regeneration
Transplanting brain tissue

16. The Nervous System Central Nervous System (CNS): Brain and spinal cord
Peripheral Nervous System: All parts of the nervous system outside of the brain and spinal cord
Somatic System: Carries messages to and from skeletal muscles and sense organs; controls voluntary behavior
Autonomic System: Serves internal organs and glands; controls automatic functions such as heart rate and blood pressure

17. Two Divisions of the Autonomic System
Sympathetic: Arouses body; emergency system
Parasympathetic: Quiets body; most active after an emotional event

18. Fig. 3-9 (a) Central and peripheral nervous systems
Fig. 3-9 (a) Central and peripheral nervous systems. (b) Spinal nerves, cranial nerves, and the autonomic nervous system.

19. Fig. 3-10 Subparts of the nervous system.

20. Fig. 3-11 Sympathetic and parasympathetic branches of the autonomic nervous system.

21. The Spinal Cord White matter: Areas where myelin is present
Spinal Nerves: 31 of them; carry sensory and motor messages to and from the spinal cord
Cranial Nerves: 12 pairs that leave the brain directly; also work to communicate messages

22. How is the Spinal Cord Related to Behavior?
Reflex Arc: Simplest behavioral pattern; occurs when a stimulus provokes an automatic response
Sensory Neuron: Nerve cell that carries messages from the senses toward the CNS
Connector Neuron: Nerve cell that links two others
Motor Neuron: Cell that carries commands from the CNS to muscles and glands
Effector Cells: Cells capable of producing a response

23. Fig. 3-12 A simple sensory-motor (reflex) arc
Fig A simple sensory-motor (reflex) arc. A simple reflex is set in motion by a stimulus to the skin (or other part of the body). The nerve impulse travels to the spinal cord and then back out to a muscle, which contracts. Reflexes provide an “automatic” protective device for the body.

24. Courtesy of Richard Haier, University of California, Irvine
3-14 In the images you see here, red, orange, and yellow indicate high consumption of glucose; green, blue, and pink show areas of low glucose use. The PET scan of the brain on the left shows that a man who solved 11 out of 36 reasoning problems burned more glucose than the man on the right, who solved 33.

25. Brain Mapping
Read article from CNN

26. Project

27. Cerebral Cortex
Cerebral Cortex: Outer layer of the cerebrum; contains 70% of neurons in CNS
Cerebrum: Two large hemispheres that cover upper part of the brain
Corticalization: Increase in size and wrinkling of the cortex

28. Split Brains
Cerebral Hemispheres: Right and left halves of the cerebrum
Corpus Callosum: Bundle of fibers connecting cerebral hemispheres
Corpus Callosum is cut; done to control severe epilepsy (seizure disorder)
Result: The person now has two brains in one body
This operation is rare and is often used as a last resort

29. Figure 3-15 Corpus Callosum

30. Fig. 3-16 Basic nerve pathways of vision
Fig Basic nerve pathways of vision. Notice that the left portion of each eye connects only to the left half of the brain; likewise, the right portion of each eye connects to the right brain. When the corpus callosum is cut, a “split brain” results. Then visual information can be directed to one hemisphere or the other by flashing it in the right or left visual field as the person stares straight ahead.

31. Right Brain/Left Brain
About 95 percent of our left brain is used for language
Left hemisphere better at math, judging time and rhythm, and coordinating order of complex movements
Processes information sequentially and is involved with analysis
Right hemisphere good at perceptual skills, and at expressing and detecting other’s emotions
Processes information simultaneously and holistically

32. Fig If a circle is flashed to the left brain and a split-brain patient is asked to say what she or he saw, the circle is easily named. The person can also pick out the circle by touching shapes with the right hand, out of sight under a tabletop (shown semi-transparent in the drawing). However, the left hand will be unable to identify the shape. If a triangle is flashed to the right brain, the person cannot say what was seen (speech is controlled by the left hemisphere). The person will also be unable to identify the correct shape by touch with the right hand. Now, however, the left hand will have no difficulty picking out the hidden triangle. Separate testing of each hemisphere reveals distinct specializations, as listed above.

33. Corpus Callosum Cut
Video

34. Central Cortex Lobes Occipital: Back of brain; vision center
Parietal: Just above occipital; bodily sensations such as touch, pain, and temperature (somatosensory area)
Temporal: Each side of the brain; auditory and language centers
Frontal: Movement, sense of smell, higher mental functions
Contains motor cortex; controls motor movement

35. The left and right brain have different information processing styles
The left and right brain have different information processing styles. The right brain gets the big pattern; the left focuses on small details.

36. Brain Parts
Worksheet

37. When the Brain Fails to Function Properly
Association Cortex: Combine and process information from the five senses
Aphasia: Language disturbance resulting from brain damage
Broca’s Area: Related to language and speech production
If damaged, person knows what s/he wants to say but can’t say the words
Wernicke’s Area: Related to language comprehension; in left temporal lobe
If damaged, person has problems with meanings of words, NOT pronunciation

38. When the Brain Fails to Function Properly (cont.)
Agnosia: Inability to identify seen objects
Facial Agnosia: Inability to perceive familiar faces

39. Brain Injury
Brain Injury Worksheet

40. His and Her Brains
Read page 66

41. Hindbrain (Subcortex)
Immediately below cerebral hemispheres
Brainstem : Consists mainly of medulla and cerebellum
Medulla: Controls vital life functions such as heart rate, swallowing, and breathing
Pons (Bridge): Acts as a bridge between medulla and other structures
Influences sleep and arousal
Cerebellum: Located at base of brain
Regulates posture, muscle tone, and muscular coordination

43. Fig.3-22 This simplified drawing shows the main structures of the human brain and describes some of their most important features. (You can use the color code in the foreground to identify which areas are part of the forebrain, midbrain, and hindbrain.)

44. Hindbrain (Subcortex): Reticular Formation (RF)
Reticular Formation (RF): Inside medulla and brainstem
Associated with alertness, attention, and some reflexes (breathing, coughing, sneezing, vomiting)
Reticular Activating System (RAS): Part of RF that keeps it active and alert
RAS acts like the brain’s alarm clock
Activates and arouses cerebral cortex

45. Forebrain
Structures are part of Limbic System: System within forebrain closely linked to emotional response and motivating behavior
Thalamus: Relays sensory information on the way to the cortex; switchboard
Hypothalamus: Regulates emotional behaviors and motives (e.g., sex, hunger, rage, hormone release)
Amygdala: Associated with fear responses
Hippocampus: Associated with storing permanent memories; helps us navigate through space
Electrical stimulation of the brain (ESB): Is the direct electrical stimulation and activation of the brain tissue

46. Fig Parts of the limbic system are shown in this highly simplified drawing. Although only one side is shown, the hippocampus and the amygdala extend out into the temporal lobes at each side of the brain. The limbic system is a sort of “primitive core” of the brain strongly associated with emotion.

47. The Brain in Perspective- Beyond the Biocomputer
Endocrine system: Made up of glands that pour chemicals directly into the bloodstream or lymph system
Hormones: Chemicals in blood that are carried throughout the body that affect internal activities and behavior.

48. Endocrine System
Glands that pour chemicals (hormones) directly into the bloodstream or lymph system
Pituitary Gland: Master gland that regulates growth via growth hormone
Too little means person will be smaller than average
Hypopituitary Dwarfs: As adults, perfectly proportioned but tiny
Treatable by using human or synthetic growth hormone; will add a few inches
Treatment is long and expensive

49. Endocrine System (cont.)
Too much growth hormone leads to giantism
Excessive body growth
Acromegaly: Enlargement of arms, hands, feet, and facial bones
Caused by too much growth hormone secreted late in growth period
Andre the Giant
Pituitary also governs functioning of other glands, especially thyroid, adrenals, and gonads

50. PRINCESS BRIDE

51. Endocrine System (cont.)
Pineal Gland: Regulates body rhythms and sleep cycles.
Releases hormone melatonin, which responds to daily variations in light
Thyroid: In neck; regulates metabolism
Hyperthyroidism: Overactive thyroid; person tends to be thin, tense, excitable, nervous
Hypothyroidism: Underactive thyroid; person tends to be inactive, sleepy, slow, obese

52. The Adrenal Glands
Adrenals: Arouse body, regulate salt balance, adjust body to stress, regulate sexual functioning; located on top of kidneys
Releases epinephrine and norepinephrine (also known as adrenaline and noradrenaline)
Epinephrine arouses body; is associated with fear
Norepinephrine arouses body; is linked with anger

53. The Adrenal Glands (cont.)
Adrenal Medulla: Inner core of adrenals; source of epinephrine and norepinephrine
Adrenal Cortex: Produces hormones known as corticoids
Regulate salt balance
Deficiency in some types will cause powerful salt cravings
Also help body to adjust to stress
Secondary source of sex hormones
Oversecretion of adrenal sex hormones can cause virilism: exaggerated male characteristics (Bearded woman)
May also cause premature puberty if oversecretion occurs early in life

54. Redundancy
Redundancy: duplication of the brains functions in multiple brain structures, increases complexity of the brain, how a child can overcome brain damage and function have “normal” functioning brain
Dozens of brain areas do what one could manage alone

55. Plasticity
Plasticity: Brain’s ability to change its structure and functions, flexibility of the brains organization
Based on increased branching of dendrites in young age if brain damage occurs (ages birth to 5 best)
chances decrease after age 10

56. Homework Quiz #5, take home Grade 41-70 Diagnostic AP test
Read page 66, write one paragraph summary
on “His & Her Brain”
Read pages 75-78, write 2 paragraph summary on
“Handedness”
Define Follwing terms
EBS, pg 70
use pgs for all below, or online power Chapter 3 point found on Bird website
CT Scan,
MRI
EEG
MANSCAN
PET Scan
MEG Scan

57. Fig Neuroscientists are searching for ways to repair damage caused by strokes and other brain injuries. One promising technique involves growing neurons in the laboratory and injecting them into the brain. These immature cells are placed near damaged areas, where they can link up with healthy neurons. The technique has proved successful in animals and is now under study in humans.

58. Fig A direct brain-computer link may provide a way of communicating for people who are paralyzed and unable to speak. Activity in the patient’s motor cortex is detected by an implanted electrode. The signal is then amplified and transmitted to a nearby computer. By thinking in certain ways, patients can move an on-screen cursor. This allows them to spell out words or select from a list of messages, such as “I am thirsty.”

59. Researching the Brain Ablation: Surgical removal of parts of the brain
Deep Lesioning: A thin wire electrode is lowered into a specific area inside the brain; Electrical current is then used to destroy a small amount of brain tissue
Electrical Stimulation of the Brain (ESB): When an electrode is used to activate target areas in the brain
Electroencephalograph (EEG): Detects, amplifies, and records electrical activity in the brain

60. Researching the Brain (cont.)
Computed Tomographic Scanning (CT): Computer-enhanced X-ray of the brain or body
Magnetic Resonance Imaging (MRI): Uses a strong magnetic field, not an X-ray, to produce an image of the body’s interior
Functional MRI: MRI that makes brain activity visible
Positron Emission Tomography (PET): Computer-generated color image of brain activity, based on glucose consumption in the brain

61. © Huntington Magnetic Resonance Center, Pasadena, California
An MRI scan of the brain.

62. Washington University School of Medicine, St. Louis
PET scans.

63. Washington University School of Medicine, St. Louis
The bright spots you see here were created by a PET scan. However, here they have been placed over an MRI scan so that the brain’s anatomy is visible. The three bright spots are areas in the left brain related to language. The spot on the right is active during reading. The top-middle area is connected with speech. The area to the left, in the frontal lobe is linked with thinking about a word’s meaning (Montgomery, 1989).

64. Fig The functions of brain structures are explored by selectively activating or removing them. Brain research is often based on electrical stimulation, but chemical stimulation is also used at times.

65. Fig An EEG recording.

66. Brain Drain
Great Brain Drain worksheet

67. Take Home Test!