1. Neuroscience, Genetics and Behavior

2. True or False?
“Basic biological processes underlie all human behavior.”
Various branches of psychology rest on this foundation.

3. Biological Psychology (or Psychobiology)
The most significant transformation in modern psychology
AKA Biopsychologists, behavioral neuroscientists, behavior geneticists, physiological psychologists, neuropsychologists…

4. An intro to neuroscience… Explain the following…
“Modern psychology views each individual as a biopsychosocial system.”
“Everything psychological is simultaneously biological.”
“The mind is what the brain does..”
“A brain simple enough to be understood is too simple to produce a mind able to understand it.”

5. Introducing the neuron…
Simple definition:
a nerve cell
The incredible neuron….
basic unit of information processing or,… building block of the brain. (and nervous system)
Affects everything we do…

6. A vastly complex system…
Facts about neurons:
100 billion neurons in the human brain and CNS! (and 400 trillion synapses!)
A grain of sand-size part of the human brain holds 100,000 neurons!

7. Neural Structure Dendrite (receives impulse) Axon (transmits impulse)
Branching extensions of a neuron / receive messages / conduct impulses toward the cell body
Axon (transmits impulse)
extension of a neuron, ending in branching terminal fibers, through which messages are sent to other neurons or to muscles or glands
Remember: “Axons speak, dendrites listen…”
Myelin Sheath (speeds impulse)
a layer of fatty cells segmentally encasing the fibers of many neurons
Speeds transmission of neural impulses

8. Neural Structure
So what happens when the myelin sheath begins to wear out?
Alzheimer's (impedes transmissions affecting thought process)
Multiple sclerosis: interferes with muscle control (as message to muscles is impeded..)

9. Neural Structure

10. Neural Communication “an electrochemical process…”
“Neural communication is a conversation between cells that generates our thoughts, actions, moods and memory.”

11. Neural Communication Action Potential
a brief electrical charge that travels down an axon
Stimulated when neuron receives signals from sense receptors stimulated by heat, pressure or light

12. Neural Communication “What one neuron tells another neuron is simply how much it is excited.”
Each neuron has a threshold…
the level of stimulation required to
trigger an action potential (or neural impulse)
Determined by excitatory and inhibitory triggers that determine the action potential (neural impulse)

13. Neural Communication…
Neurotransmission = electro-chemical process
The chemistry to electricity process involves the exchange of ions
Ions: electrically charged atoms

14. Ions… Resting Potential
Fluid inside a resting axon has negatively charged atoms
Fluid outside the axon membrane has positively charge atoms
Natural state of inside / outside ions = resting potential
Axon’s surface is selectively permeable (it decides what it allows in..)

15. Reaching a Neuron’s Threshold…
When the neuron fires…
Axon opens gates (selectively permeable) and +charged sodium ions flood the membrane
+sodium ions cause depolarization
Depolarization causes reaction as axons pass the impulse down the chain (like dominoes)
Opens and closes times /second!

16. Reaching a Neuron’s Threshold…
Refractory Period
Once impulse has been passed, the axon pumps +ions back out of membrane, and thus recharges
All or none response
Increased stimulus does not increase the action potential’s intensity (a gun either fires or doesn’t)

17. Neural Communication Cell body end of axon
Direction of neural impulse: toward axon terminals

18. Neural Communication Synapse (Where the action is…) Neurotransmitters
junction between the axon of the sending neuron and the dendrite of the receiving neuron
synaptic gap or cleft (less than a millionth of an inch!)
Neurotransmitters
chemical messengers that carry the impulse (“message”) from one neuron to the next
neurotransmitters bind to receptor sites (“lock and key”
Thus ions passed on to new neuron: exciting or inhibiting its readiness to fire..

19. Neural Communication Reuptake
Excess neurotransmitters are reabsorbed by the sending neuron

20. Neural Communication

21. Neurotransmitters
About 75 have been discovered
We will study 7-8

22. Neurotransmitters (Take notes on last 2 listed)

23. Neurotransmitters GABA Glutamate Inhibitory neurotransmitter
Undersupply = seizures, tremors, insomnia
Glutamate
Excitatory neurotrasmitter
Involved in memory
Too much = migraines, seizures
Excitotoxicity: “excite a neuron to death” (glial cells help prevent…)
Chinese food- MSG (glutamate) = headaches

24. Neurotransmitters Acetylcholine [ah-seat-el-KO-leen] ACh
triggers muscle contraction (movement, learning, memory)
Undersupply = Alzheirmer’s

25. Neurotransmitters Endorphins [en-DOR-fins] “morphine within”
natural, opiate-like neurotransmitters
linked to pain control and to pleasure
“Runners high”
Opium, heroine addicts: brain stops producing natural opiates, thus “withdraws”

26. Neurotransmitters… Norepinephrine Mood
Too much = mania / too little = depression
Imbalance = bipolar disorder

27. Neurotransmitters Serotonin Sleep, eating, mood Related to depression
Prozac (anti-depressant drug) raises serotonin levels

28. Neurotransmitters Dopamine Perceptual awareness, muscle control
Too much = Schizophrania (up to 6x more dopemine)
A Beautiful Mind / The Soloist
Too little = Parkinson’s Disease (tremors: Muhammad Ali)

29. Drugs Affect Neurotransmission
Drugs can be used to affect communication at the synapse
Agonists excite, or mimic the neurotransmittors / or block reuptake (drug addicts and withdraw)
Antagonists block, or inhibit neurotransmitters signal (examples=Botox/ botulism blocks Ach)
A complicated process: Brain has blood-brain barrier that blocks out unwanted chemicals

30. Neural Communication Neurotransmitter molecule Receiving cell membrane
Agonist mimics
neurotransmitter
Antagonist
blocks
neurotransmitter
Receptor site on
receiving neuron

31. Neural Communication
Dopamine Pathways
Serotonin Pathways

32. Remember… Communication within the neuron is…….
Electrical
Communication between neurons is….
chemical

33. Glial cells (Glia) Make up 90% of brain’s cells
Protect, nourish neurons
Current research suggests possible action potentials, debate as to role…
See p. 45: Alchemy of Mind

34. An Alchemy of Mind
Explain fully each of the following quotes from your reading.
“Neurons speak an elite pidgin neither chemical nor electrical but a lively buzz that joins the two, an electrochemical lingo all their own.”
“It is important to realize that what one neuron tells another neuron is simply how much it is excited.”
It is a small liquid space, as is the air between two whispering lovers, yet so much life happens there. Each junction is a bazaar full of commerce, intrigue and possibility. In the brain, everything depends on almost nothing, a lively space….”
“Coexisting as they must, both neurons and glia are dependable, dependent… central to the brain’s social fabric and perpetual hum.”

35. The Nervous System Nervous System Central Nervous System (CNS)
the body’s speedy, electrochemical communication system
consists of all the nerve cells of the PNS and CNS
Central Nervous System (CNS)
the brain and spinal cord (encased in bone)
Peripheral Nervous System (PNS)
connect the central CNS to the rest of the body’s sense receptors

36. The Nervous System Central (brain and spinal cord) Nervous system
Autonomic (controls
automatic action of
internal organs and glands)
Somatic (Skeletal) (controls
voluntary movements of
skeletal muscles)
Sympathetic
(arousing: flight or fight)
Parasympathetic
(calming)
Peripheral

37. The Autonomic Nervous System
part of the PNS: controls the glands and the muscles of the internal organs (involuntary)
A Dual System
Sympathetic Nervous System
arouses the body, mobilizing its energy in stressful situations (“Fight or flight”, or “sympathy in crisis”)
Parasympathetic Nervous System
calms the body, conserving its energy
“paramedics to calm down”- lowers heartbeat etc.

38. The Nervous System

39. The Nervous System

40. The Peripheral Nervous System
Links CNS to body’s sense receptors
For each of the following, identify it as a function of the Somatic or Autonomic Nervous System.
Sneezing
Turning the page
Scratching your head
Breathing
Kissing your date
Digesting your food

41. Communication in the Nervous System
Nerves
neural “cables” containing millions of axons
part of the PNS (carry PNS info)
connect the CNS with muscles, glands, and sense organs
Extend through the body

42. Communication in the Nervous System
3 neurons that carry info in the nervous system
Sensory Neurons (afferent: millions!)
neurons that carry incoming information from the sense receptors to the central nervous system
Motor Neurons (efferent: millions)
carry outgoing information from the CNS to muscles and glands
Interneurons (billions!)
CNS neurons that internally communicate / process sensory and motor neurons (most complex)

43. The Central Nervous System
“The motherboard of our humanity…”
10’s of billions of neurons
Brain and spinal cord
Spinal cord: Information highway connecting PNS to the brain

44. Reflexes
Spinal Reflex: Autonomic response to stimuli (Single sensory neuron, single motor neuron, interneuron:…..Brain’s not involved!)

45. Pain Reflex Sensory neuron, interneuron, motor neuron
a simple, automatic, inborn response to a sensory stimulus

46. The Brain
Center for all sensory information and voluntary movement (receives, interprets, decides…)
Without the brain…no pain or pleasure, no voluntary movement

47. Neural Networks A Complex Mystery…
interconnected neural cells
with experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results
computer simulations of neural networks show analogous learning
Inputs
Outputs
Neurons in the brain
connect with one
another to form networks
The brain learns by modifying
certain connections in
response to feedback

48. In other words…
“Neurons that fire together... wire together.”

49. The Endocrine System The body’s 2nd communication system
Interconnected with nervous system

50. Endocrine System ES glands produce hormones
Hormones travel through bloodstream to affect body
Influences growth, mood, metabolism, reproduction etc.
Thus ES works to keep body in balance in response to stress, exertion, thoughts etc.
“Snail mail”- Much slower to process, several seconds, but lasts longer…

51. Important Glands… Pituitary Gland (the master gland..)
Pea sized, in middle of brain
Influences growth
Influences other Endocrine glands’ release of hormones
Controlled by hypothalamus (brain)
Brain – pituitary – other glands – hormones – brain (complex system: blend of Endocrine system and nervous systems)

52. Pituitary Gland

53. Adrenal Glands Located on top of kidneys
Release epinephrine and norepinephrine (adrenaline and noradrenaline)
Heart rate, blood sugar, blood pressure etc.

54. Adrenal Glands

55. What do you know about the human brain?
Answer the following as true or false.
The larger the brain, the smarter the animal.
The brain’s structure is a better indicator of intelligence than it’s size.
The right side of the brain controls the right side of the body, and so on with the left.
You fall in love with your heart, not your brain.
Your brain uses 20% of your body’s energy, but makes up only 2% of your body’s weight.

56. What do you know about the human brain?
True-False continued…
Your brain is about the size of a cantaloupe and is wrinkled like a walnut.
Your brain feels like a ripe avocado and looks pink because of the blood running through it.
The baby’s brain grows 3x in size during its first year.
At birth, the human brain weighs 4/5 of a pound, while an adult’s weighs about 3 pounds.
Your brain generates about 25 watts of power while awake- or enough to illuminate a light bulb.

57. The typical human brain…
contains about 100 billion neurons
consumes about ¼ of the body’s oxygen
spends most of the bodies calories
Is 70% water!!!
weighs about 3 pounds

58. The Brain Lesion tissue destruction
a naturally or experimentally caused destruction of brain tissue

59. Neuroimaging Techniques
“Mapping the brain”

60. Electroencephalogram (EEG) Detects Brain Waves
Scans / measures electrical activity across brain
can specify waves to specific stimulus
Sleep research

61. CAT (computed tomography) Scan
Multiple x-ray pictures = 3D image of brain structure
Structure only- not function
Tumors, physical abnormalities

62. PET (positron emission tomography) Scan
Can measure amount and movement of chemicals in the brain (glucose)
Check brain’s activity to specific tasks (the more used, the more activity…)
Neurotransmitters and drugs

63. MRI (magnetic resonance imaging)
Like CAT, but used magnetic fields to measure density and location of brain material
soft tissue; allows us to see structures within the brain

64. MRI Scan

65. FMRI (Functional MRI) Reveals brains’ functioning as well as its structure (IOW: MRI + PET)
Watches brain “light up” by concentrations of blood flow to specific areas

66. The Old Brain (hind brain) “Parts shared with Distant Ancestors”
“Life Support System”

67. Brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull
responsible for automatic survival functions

68. Medulla [muh-DUL-uh] base of the brainstem
controls heartbeat, blood pressure and breathing

69. Pons: Help coordinate movement, facial expressions
Connects hindbrain with mid & forebrain

70. Cerebellum Cerebellum [sehr-uh-BELL-um]
the “little brain” attached to the rear of the brainstem
coordinate voluntary movement and balance (fine muscle movements)

71. Cerebellum

72. Reticular Formation (Midbrain)
a nerve network in the brainstem that plays an important role in controlling arousal and sleep!

73. Explain the significance of the next slide…

75. The Brain

76. The Forebrain (Thought and Reason)
Thalamus [THAL-uh-muss]
the brain’s sensory switchboard, located on top of the brainstem (all but smell)
it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

77. The Limbic System Limbic System
a doughnut-shaped system of neural structures
at border of the brainstem and cerebral hemispheres
associated with emotions, drives and memory
includes the hippocampus, amygdala, and hypothalamus.

78. The Limbic System

79. The Limbic System

80. Amygdala [ah-MIG-dah-la]
components of the limbic system and are linked to emotion (fear and aggression)

81. Hippocampus
Memory (processes new memories and stores in cerebral cortex)

82. Hypothalamus
neural structure / below (hypo) the thalamus; Basic Drives:
hunger
thirst
body temperature
Sex drive (libido)
helps govern the endocrine system via the pituitary gland
is linked to emotion

83. The Limbic System
Electrode implanted in reward center

84. Hemispheres of the Brain
Left:
Language and logic
Right:
Spatial, creative

85. Why do most strokes affect the right side of the body?
Most strokes occur in the left hemisphere

86. The Cerebral Cortex (Thin layer of densely packed neurons: .0039-inch)
intricate fabric of interconnected neural cells that covers the cerebral hemispheres (20 billion nerve cells!)
body’s ultimate control and information processing center
The larger the cortex, more adaptability, capacity for learning
Wrinkles = fissures (3 sq ft w/o them!)
*Perceiving, thinking, speaking*
Glial Cells
cells in the nervous system that support, nourish, and protect neurons
Aka neuron nannies or glue cells

87. The Cerebral Cortex (Each hemisphere has 4 lobes)
Frontal Lobes
involved in speaking and muscle movements: judgement, logic (abstract thought, emotional control)
Parietal Lobes
include the sensory cortex (sensory center/ senses)
Occipital Lobes
Vision: receive visual information from the opposite visual field
Temporal Lobes
Hearing, or auditory areas

88. The Cerebral Cortex

89. The Cerebral Cortex Motor Cortex Sensory Cortex
at the rear of the frontal lobes / controls voluntary movements
What parts of body occupy most cortical space?
Fingers and mouth (require most precise control)
Sensory Cortex
at the front of the parietal lobes / registers and processes body sensations
The more sensitive the body region, the more area occupied in the sensory cortex

90. The Cerebral Cortex

91. The Cerebral Cortex
Functional MRI scan shows the visual cortex activated as the subject looks at faces

92. Visual and Auditory Cortex

93. Association Areas
More intelligent animals have increased “uncommitted” or association areas of the cortex
Association areas = 75% of cortex
Interprets, integrates and acts on info processed by sensory areas
Associates sensory input with stored memories (complex mystery)

94. Language and the Brain Broca’s Area Wernicke’s Area
Location: lower left frontal lobe / Role: directs muscle movements of making speech
Wernicke’s Area
Location: left temporal lobe / Role: language comprehension and expression
Aphasia (language impairment)
usually caused by left hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding)

95. Specialization and Integration

96. Specialization and Integration
Brain activity when hearing, seeing, and speaking words

97. Brain Reorganization Plasticity brain’s capacity to modify itself
brain reorganizes / compensates after damage, injury
children have the most plasticity
Example: blind and braille- one finger used: sense of touch invades visual cortex

98. Review Question
When stroking the face of someone who’s hand has been amputated, why did the subject feel the sensation not only on his face, but also on his amputated (“phantom”) fingers?
Answer: Hand area of the sensory cortex is no longer used, thus fibers from the facial sensory areas invade the space. (Note that the hand area is between the face and arm regions of the sensory cortex.)
In other words…. Plasticity!

99. Plasticity

100. Our Divided Brain True or False:
1. Each hemisphere shares equally in performing all functions of the body.
2. The two hemispheres can be isolated by severing the corpus callosum.
3. Each hemisphere of the brain has a “mind of its own.”

101. Our Divided Brain Corpus Callosum
large band of neural fibers: 200,000,000!
connects the two brain hemispheres
carries messages between the hemispheres (billion pieces of info / second!)

102. Our Divided Brain
The information highway from the eye to the brain

103. Split Brain
Isolate the 2 hemispheres by cutting the connecting fibers between them (corpus callosum)
To remedy uncontrollable epileptic seizures
Testing the “split brain” proves specific functions of each hemisphere

104. The Split Brain Experiment Dr. Gazzaniga- 1967 Stare at the Dot…..
he.art
Which word would the split-brain patient verbalize seeing? Why?
Which word, when asked to point with his left hand, would he report seeing? Why?

105. Split Brain Explain the following…

106. The Split brain
1. If this visual was shown to the right hemisphere of a split brain patient, how might the patient identify the object?

107. The Split Brain Interesting facts about the split brain:
Subjects can simultaneously draw different figures with the left and right hand.
When the 2 hemispheres are at odds, the left will rationalize reactions it doesn’t understand.
The hemispheres are an “odd couple”, each with “a mind of its own.”

108. The Split Brain Which hemisphere is more active with…
Right brain
Left brain
Simple requests
Perceiving objects
Decision making (deliberative)
Quick intuitive responses
Recognizing faces
Perceiving , expressing emotion

109. Hemispheric Differences in the Intact Brain
Hemispheric specialization = lateralization
Blood flow, glucose, brain waves detected between hemispheres for perceptual tasks and speaking, calculating tasks (EEG, PET, FMRI)
Sedative to artery to specific hemisphere: alters specific functions of the body
If left hemisphere is sedated, what functions would be lost?
Language, right side of body limp
If sedative to right hemisphere?
Difficulty identifying themselves in altered photo, left side limp

110. Questions to consider….
1. If a word is flashed to your right hemisphere (through your left visual field), why does it take you slightly longer to state what you see than it would if flashed to your left hemisphere?
Process time through the corpus callosum
Which hemisphere would a deaf person use for sign language?
right (visual / spatial) or left (language)?
Left: to the brain, language is language

111. Handedness What percentage of humans are right handed?
90%
What ultimately makes you right or left handed?
Genetics? Pre-natal? Social-Cultural?
What expressions can you think of that discriminate against “lefties?”
Right on / right hand man / righteous / right mind -- out in left field / left-handed compliment

112. Lefties tend to be….. Musicians Mathematicians
Professional baseball / cricket players
Architects
artists

113. Disappearing Southpaws
The percentage of left-handers decreases sharply in samples of older people (adapted from Coren, 1993).
The percentage of
lefties sharply
declines with age
Age in years
14% 12 10 8 6 4 2
Percentage of
left-handedness

114. Brain Structures and their Functions