Transcript Cerebri Anatome

Stress and Cognition
The Neuroscience
Behind Stress,
Memory & Thinking
Debra S. Austin, PhD, JD
Sixty minutes of thinking of any kind is bound to lead to confusion and unhappiness.
~ James Thurber ~
 Areas
of the brain involved in learning
 Neuroscience of memory formation
 Difference between emotions and feelings
 Impact of negative emotions on learning
 Suggestions to maximize cognitive function
Learning about the Brain
 First
Illustrated Brain Manual
 Cerebri
 Modern
 Animal
Anatome 1664
brain research
Studies
 Brain Scans
 Brain Structure Scanning: X-Ray, CT, MRI
 Brain Activity Scanning: EEG, fMRI, MEG, PET, DTI
Brain Facts
3
lbs
 Size of a coconut
 Walnut shaped
 Consistency of Jell-O or chilled butter
 Evolved from the top of the spine up
 Requires
 25% of calories consumed
 20% of oxygen breathed
 25% of body’s total blood flow
Primitive Brain
 Brain
Stem, Hindbrain, or Reptilian Brain
 Governs basic motor functions
 Breathing, digestion, heartbeat, sleeping,
balance
 Key Parts: brain stem, midbrain, cerebellum
 Engaged when struggling for survival
Emotional Brain
 Inner
Brain or Limbic System
 Manages circadian rhythm, hunger, sex
hormones, addiction, and emotions
 Key Parts (in pairs, one in each hemisphere):
amygdala, hippocampus, hypothalamus,
thalamus, nucleus accumbens, and ventral
tegmental
 Engaged when experiencing an emotional
response or creating new memories
Thinking Brain
 Cerebral
 Key


Cortex
Parts
Two hemispheres linked by the corpus callosum
Four major lobes
 Frontal
lobe (language, reasoning, movement)
 Occipital lobe (vision)
 Temporal lobe (hearing)
 Parietal Lobe(taste, temperature, touch)


Outer layer is grey matter - densely-packed neurons
Inner layer is white matter
 Engaged
when using reasoning and logic to
conduct higher-order thinking
Brain Cells
 Neurons
 Communication
nerve cells
 Shaped like trees
 Information travels from the
branches (dendrites) down
the trunk (axon) and across a
tiny gap (synapse)to the next
group of dendrites
 Chemicals (neurotransmitters)
carry the information over the
synaptic gap
 Electrical-Chemical-Electrical
Over 100 Neurotransmitters
 Serotonin
(mood, anxiety, sleep)
 Endorphins (reduce pain, increase pleasure)
 Oxytocin (bonding)
 Acetylcholine (attentiveness, memory)
 Glutamate (learning, memory)
 Dopamine (motivation, pleasure, meaning)
Brainy Vocabulary
 Triune
Brain Structure
 primitive,
emotional & thinking brains
 Neuron
 tree-shaped
brain cell & unit of communication
 Neurogenesis
 the
birth of new brain cells
 In the Hippocampus & Olefactory Bulbs
 Neuroplasticity
 changes
in your brain
 Connectome
 unique
system map of neuron data pathways
Your Connectome
You
are your synapses
Your brain is a work in progress
Neurons that fire together wire together
Nondeclarative Memories
 Cannot
be experienced in conscious awareness
 Procedural
Memories
 Stored in cerebellum (primitive brain)
 Skiing, dancing, driving
 Fear
Memories
 Stored in amygdala (emotional brain)
 Flashbacks and phobias
Declarative Memories
 Require
conscious thought to be
recalled
 Stored in both emotional and thinking
brain
 Episodic Memories - Autobiographical
personal experiences
 Semantic
Memories - Learned
Knowledge: facts, concepts & words
Parts of Brain Involved in Learning
 Thinking
 Frontal
Brain
Lobe
 language, reasoning, movement
 Occipital Lobe
 vision
 Temporal Lobe
 hearing
 Parietal Lobe
 taste, temperature, touch
 Emotional
 Thalamus
Brain
 Amygdala
 Hippocampus
Laying Down a Memory
 Consolidation:
a Memory Trace is converted
to Long-Term Memory and becomes stable
in the brain
 Encoding: processing sensory information
 Thinking Brain
 Information
 Emotional
 Thalamus
enters via the senses
Brain
focuses attention, screens
information, and sends it to the Hippocampus
 Amygdala checks information for emotional
content
Thinking & Emotional Brain
Consolidation Loop
 Consolidation
During Sleep
 Information travels a neural loop from
Thinking Brain (sensory lobe of origin) to
Emotional Brain (Hippocampus) & repeats
 Takes 2-10 years
 Once
memory is fully consolidated, the
Hippocampus lets go of its relationship with the
Cortex
 Consolidated
memories are distributed
throughout the Cortex
Emotion
 An
unconscious and automatic response to
an emotional stimulus that results in physical
changes
 increased
heart rate & blood pressure
 Sweaty palms
 Blushing
 Six
Fear
Primary Emotions
Anger
Sadness Disgust
Surprise Joy
Feelings
 Emotions
are experienced as feelings
 Feelings are the conscious perceptions of
emotional responses
Stress
 Engineering
 Amount
of resistance a material offers to being
reshaped
 In Humans
 Physiological response to stressor that is measurable
by another party
 Stressor must be perceived as negative
 Stressed person must feel she has no control over
the stressor
 Stress involves some combination of 4 of the 6 primary
emotions: fear, anger, sadness and/or disgust
Types of Stress
 Acute
Stress
 Short-lived
 Triggers fight or flight response
 Can be helpful by assisting focus on novel
intellectual challenge or marshaling resources for
a significant physical challenge
 Chronic Stress
 Long-lasting
 Occurs during situations like a troubled intimate
relationship, financial struggles after a job loss, or
treatment for a life-threatening illness
Emotional Stimulus
 Endocrine
System
 Secretion & regulation of hormones in
bloodstream
 Autonomic System
 Mediates physiological changes in body
 Skeletal Motor System
 Controls behaviors such as freeze, fight,
flight, and facial expressions
Endocrine System
 Main
Stress Hormones: Adrenalin &
Glucocorticoids
 Major Glucocorticoid is Cortisol
 Glucocorticoids tell the Autonomic
System to
 Elevate heart rate & blood
pressure
 Mobilize energy
 Slow digestion
 Suppress immune system
 Evolutionary Purpose – quick
response to ensure survival
Elevated Glucocorticoids
 Physical
 Impaired
Immune Response
 Increased Appetite & Food Cravings
 Increased Body Fat
 Increased PMS & Menopause Symptoms
 Decreased Muscle Mass, Bone Density &
Libido
 Emotional
 Increased Mood Swings, Irritability & Anger
 Increased Anxiety & Depression
Memory Consolidation
Your Brain on Glucocorticoids
 Suppression
of Neurogenesis (birth of new brain
cells) in Hippocampus
 Damage to Hippocampus can create cycle where
greater amounts of Glucocorticoids are released,
producing additional Hippocampal atrophy
 Hippocampal Neurodegeneration & Cell Death
Impact of Stress on Cognition
 Deterioration
in memory, concentration,
problem-solving, math performance,
language processing, curiosity, creativity,
and motivation
 Hippocampi
shrink in size
 Depression
 Post-Traumatic
Stress Disorder
 Repeated exposure to jet lag
Reverse Hippocampal Damage
Increase Neurogenesis
Exercise
Healthful
Sleep
Antidepressants
Exercise
 Enhances
blood and oxygen flow
 Stimulates production of Brain Derived
Neurotropic Factor (BDNF)
 30 minutes of aerobic exercise 2 to 3 times
per week + strength training for maximum
cognitive benefit
Increased Blood Flow
 Improves
blood flow deeper into body
tissues
 Enhances distribution of food and
elimination of waste
 Increases blood volume in Hippocampus
 Maintains health and functioning of
Hippocampus
BDNF
 Protein
that helps
 Create new neurons
 Protect existing neurons
 Encourage synapses formation

BDNF production enhanced by
 Exercise
 Calorie Reduction
 Intellectual Stimulation
 Curcumin (active ingredient in spice Turmeric)
 Omega-3 Fat DHA
Sleep




90 Minutes to 2 Hours to Stage 5 REM Sleep
Hippocampus & Amygdala very active during REM
Communication between neurons at rate equal to or
higher than when awake
Memory consolidation genes activated during REM,
which helps formation of new neural connections
Sleep Research
 Subjects
awakened during REM lost ability to learn
new information
 Loss of 1 night of sleep = 30% cognitive decline
 Loss of 2 nights of sleep = 60% cognitive decline
 Less than 6 hours of sleep for 5 nights in a row = 60%
cognitive decline
 Sleep Deprivation



Diminishes attention, working memory, executive
function, quantitative skills, logical reasoning ability,
mood, and fine & gross motor control
Accelerates Aging Process
Impairs ability to use fuel/food creating risk of
diabetes and obesity
Circadian Rhythm
 Arousal

Neurons, hormones & chemicals keep body awake
 Sleep



(Early Chronotypes)
10% of population
Productive early in day & want to sleep about 9pm
 Owls

Drive
Neurons, hormones & chemicals put body to sleep
 Larks

System
(Late Chronotypes)
20% of population
Productive late in day & may want to retire at 3am
 Hummingbirds

70% in middle of the spectrum
Siesta Time
 Arousal
System & Sleep Drive flat-line in the afternoon
 Causes a desire to nap
 Naps improve cognition


26-minute nap improved NASA pilot performance by
34%
45-minute nap improved cognition for at least 6 hours
Antidepressants
 Increase
the rate of neurogenesis
 Includes SSRIs (selective serotonin uptake inhibitors)
Maximize Cognitive Function
 Commit
to and perform regular exercise
 Make regular and adequate sleep a priority
 If treated with antidepressants, continue treatment
Article & More Brainy Vocabulary
 SSRN
 Debra
Austin
 Killing Them Softly: Neuroscience Reveals How
Brain Cells Die From Law School Stress
 Learn about the hidden law school curriculum
and what the Carnegie Report has to say about it