Neuroscience

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Neuroscience Behavior

• Chapter 3
• Psyc103019
• Jen Wright
• T/R 1215-130

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• If we want to begin to understand the complexity
  of human behavior, we need to first look to the
  brain

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true/false?

• The human brain is gray in color and firm to the
  touch.
• False the (living) human brain is deep red in
  color and squishy to the touch.
• Most people only use about 10 of their brains.
• False all people use 100 of their brains
  (though not 100 of the time).
• Alcohol kills brain cells.
• False alcohol, in small quantities, can
  actually improve brain function.
• Alcohol abuse can lead to brain dysfunction, such
  as Wernicke-Korsakoff syndrome (which kills off
  dendrites).
• So, alcohol can impair brain functioning, but it
  does not kill cells.

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true/false?

• Your are born with 100 billion neurons and that
  is all you get no new neurons are created after
  youre born.
• False we now know that neurogenesis occurs even
  in mature adult brains.
• Neurogenesis occurs in response to exposure to
  novel environmental stimuli.
• Two periods of rapid neurogenesis are infancy and
  adolescence.

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neuron
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major types
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electrical signals
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myelin sheath
greater speed distance
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chemical signals
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neurotransmitters

• Chemical forms of communication
• Dopamine
• regulates movement, motivation, emotional
  pleasure, arousal
• Serotonin
• regulates hunger, sleep, arousal, moods,
  aggressive behavior
• Endorphins
• Act within pain pathways and emotional centers of
  brain
• Norepinephrine
• Controls mood and arousal.

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• Quiz Q 1 T/F Electrical signals are all or
  nothing (the neuron either fires or it doesnt).
• A) T
• B) F
• Quiz Q 2 T/F Chemical signals are variable
  and subject to lots of environmental influences.
• A) T
• B) F

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• Quiz Q 3 Agonists _____ the chemical signal and
  antagonists ____ the chemical signal.
• A) enhance/increase block/decrease
• B) block/decrease enhance/increase
• C) neither A nor B

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how drugs effect neurotransmitters
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drugs and neurotransmitters

• What do drugs that we ingest every day do to
  neural functioning?
• Caffiene adenosine antagonist
• Nicotine dopamine agonist
• Alcohol GABA-receptor agonist
• How about harder drugs?
• Marijuana anandamide antagonist, dopamine
  agonist
• Cocaine dopamine, serotonin, norepinephrine
  agonist
• Ecstasy serotonin agonist
• Heroine GABA-receptor antagonist, dopamine
  agonist

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• McGill

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?
?
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• Quiz Q4 The two parts of the autonomic nervous
  system are
• A) the frontal parietal systems
• B) the peripheral central systems
• C) the sympathetic parasympathetic systems
• D) none of the above

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Autonomic nervous system

• Sympathetic nervous system
• Prepares the body for action in threatening
  situations
• triggered in the presence of novel stimuli
• known stimuli that has an emotional marker
• Parasympathetic nervous system
• Helps the body return to a normal resting state.
• What sorts of environments/activities stimulate
  this?
• Problem of modern life
• What implications do our modern life-style have
  for the healthy functioning of these two systems?

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The three brain regions

• Evolutionary history of the brain
• Quiz Q 5 What is the oldest part?
• A) Midbrain
• B) Hindbrain
• C) Forebrain

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The three brain regions

• Evolutionary history of the brain
• Quiz Q 6 What is the youngest part?
• A) Hindbrain
• B) Forebrain
• C) Midbrain
• What part is the human part?
• Why?

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• What does the limbic system do?
• Quiz 7 The limbic system includes both the
  hippocampus and amygdala.
• A) True
• B) False
• Why is this important?
• What function do they serve?

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basal ganglia

• Helps to direct intentional behavior
• Punishment-Reward system
• Dopaminergic system pleasure/pain
• Relevance for addictive behaviors?
• Altruism vs. self-interest
• Swedish incident

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Four lobes

• Frontal lobe voluntary movement, thinking,
  personality, executive function, and
  intentionality
• Occipital lobe vision functions
• Temporal lobe hearing, language processing, and
  memory
• Parietal lobe spatial location, attention, and
  motor control

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Motor somatosensory cortices
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• Quiz 8 The motor cortex represents the number of
  sensory neurons in the different parts of the
  body.
• A) True
• B) False
• Quiz 9 A pianists hands will have greater
  representation in the motor/somatosensory
  cortices than the rest of us.
• A) True
• B) False

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Two hemispheres

• Quiz 10 What connects the two hemispheres?
• A) Callus Corposum
• B) Corpus Callosum
• C) Medial Fibers
• Left hemisphere
• serial processor
• linear thinking
• planning past future
• language
• Right hemisphere
• parallel processor
• associative thinking
• present moment
• images

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split brain

• When the corpus callosum is severed, the two
  hemispheres function as separate brains
• Left language brain
• Right images brain

left
right
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Gene/Environment Interaction

• Two levels of environmental influence
• Environment
• Genes Genotype
• Genes Phenotype

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• Most development happens outside (instead of
  inside) the womb
• Quiz 11 The human brain is 75 of its adult
  size at birth.
• A) True
• B) False
• False. The human newborns brain is 25 its adult
  size.
• Monkey newborn 70 adult size.
• Most growth occurs in first 3 yrs
• 3 yr old 80 adult size
• What is the significance of this?

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brain development

• Neurogenesis proliferation of neurons through
  cell division
• At peak, 250,000 cells born every minute
• Synaptognesis formation of connections
• Synaptic connections double in first 6 months
• Synaptic pruning elimination of excess synapses
• Streamlines neural processing
• Myelination insulating sheath
• Happens into adolescence

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importance of experience

• Plasticity brains ability to change w/
  experience
• Experience-expectant plasticity (experiences
  present throughout evolution)
• Economizes on material encoded in genes
• Development will occur within a normal range of
  environments
• Level of vulnerability in timing
• Sensitive periods

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comprehension
production
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both languages
2nd language
native language
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mirror neurons

• Found in the frontal and parietal lobes
• Fire when you engage in an activity (reaching out
  ones hand) and when you observe someone else
  engaging in the same activity.
• Fire more strongly when action has some purpose
  or content (reaching out ones hand for a cup).
• MNs play a clear role in learning/imitation.
• May also play a role in mind-reading (grasping
  intentions, goals, desires).

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importance of experience

• Experience-dependent plasticity (experiences of
  individual)
• Brain sculpted by idiosyncratic experiences
• Brain responsive to richness of stimuli
• Important in development of expertise
• More brain resources dedicated to processing
• E.g. musicians cortical representation of hands

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difference between species

• We share 98 of our genetic material with other
  primates.
• So, what is the difference between us and
  chimpanzees?
• Brain size? The human brain is about 2/3rds
  larger than the brain of a chimpanzee.
• Adult human brain 1300-1400 grams
• Newborn human brain 350-400 grams
• Chimpanzee 420 grams

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• But brain size cant be the whole story.
• Why?
• Many mammals have larger brains that we do.
• Bottle-nosed dolphin 1500-1600 grams
• Humpback whale 4600-4700 grams
• Elephant 4700-4800 grams
• Killer whale 5600-5700 grams
• Sperm whale 7800 grams

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• Encephalization Quotient (EQ)
• Average brain mass/body weights for a species.
• Average for species/average mammalian value.
• EQ??IQ

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• Brain complexity matters for intelligent
  behavior
• Higher EQ
• Greater social complexity
• Better problem-solving abilities
• Abstract concepts
• Creative behavior
• Self-recognition
• Playful behavior

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• Alex the grey parrot check out on YouTube.

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Techniques for studying the brain

• Brain damage

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Machines to study the brain

• EEG
• Measures brain electrical activity
• CT scan
• X-ray scan
• PET scan
• Positron emission tomography (blood flow)
• fMRI
• Magnetic tracking of hemoglobin (blood flow)

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EEG
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PET scan
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fMRI