1. Understanding the Impact of Stress
on Brain Development and Learning

2.  Merriam-Webster define stress as:
A physical, chemical or emotional factor that
causes bodily or mental tension

3.  Acute stress is general short-term with a
clearly defined beginning and end
 Chronic stress is long-term and prolonged
stress with no clear ending
 Both acute and chronic stress trigger the
physiological stress response

4.  Triggering of the sympathetic nervous system
which prepares the body to deal with
perceived threat by:
◦ Increase of heart rate and blood pressure
◦ Increase of cortisol – “stress” hormone which has
anti-inflammatory and immunosuppressive
properties
◦ Decline of parasympathetic activity which regulates
“automatic” bodily functions and maintains
homestasis

6. ◦ Shorter form of
the serotonin
transporter is
associated with
vulnerability to
increased
response to
stress by
developing
depressive
illness and
alcoholism

7. ◦ An allele of the monoamine oxidase A gene result
in more vulnerability to abuse in childhood,
increased risk of becoming an abuser & show
antisocial behaviors.

8.  Early abuse can result in life long emotional
reactivity and stress hormone reactivity –
both associated with cognitive decline and
shorter lifespan in animal studies

9.  Stress reduction in infants can be influenced
by maternal bonding through a variety of
factors
◦ Physical proximity
◦ Modeling
 Early patterns “hard-wire” the stress
response –critical period during 1st nine
months

10.  Males most typically mirror the fight or flight
response
 Females engage fight or flight AND befriend

11.  There is an inverted relationship between
learning and levels of cortisol
 During acute stress, higher levels of cortisol
result in:
◦ Enhanced immunity
◦ Enhanced memory
During chronic or prolonged stress,
the increased levels of cortisol result
in:
◦ lower immune response
◦ Impaired cognitive functioning

12.  The Hippocampus is
the brain structure
primarily responsible
for learning and
memory
 The Hippocampus is
highly sensitive and
malleable
 Cortisol decreases
and retracts the
dendritic growth in
the hippocampal area

13.  Within the Hippocampus, is the dentate gyrus,
a structure which seems to play a role in the
memory of sequences of events
 It has high plasticity and is constantly
producing new neurons, even throughout
adult life.
 Certain types of stress suppress neurogenesis
and cell survival in the dentate gyrus

14.  Cortisol inhibits long-
term potentiation – cell
sensitivity in
communication
 Adolescent brain is more
receptive to long-term
potentiation without
interference

15.  Repeated or chronic stress causes dendritic
shortening in the medial prefrontal cortex
 The results in impairment in attention set
shifting

16.  Both acute and chronic stress produce
dendritic growth in neurons in the amygdala.
 The results of include:
◦ Increases anxiety
◦ Increased aggression

17.  In animal research, chronic stress causes
atrophy of neurons in the hippocampus and
prefrontal cortex
 and
 Hypertrophy of neurons in the amygdala
 Results:
◦ Decreased learning and memory
◦ Increased anxiety and aggression

18.  The results from
animal studies are
mirrored in humans
through a loss of
hippocampal volume
and an increase in
amygdala volume in
MRI studies
 PET scans also
demonstrate altered
patterns of activity in
the related brain areas
during stress

19.  Learn stress
management – variety
of techniques
 Problem-focused –
changing the stressor
 Emotion focused –
changes our response
to the stressor

20.  Physical
 Cognitive
 Emotional
 Behavioral

21.  Physical Techniques:
Exercise Meditation
Relaxation

22.  Cognitive Techniques:
Social Comparisons Re-Evaluation
Distraction

23.  Emotional Techniques:
Social Support Release
Laughter

24.  Behavioral Techniques:
Helping Others

25.  Optimism is associated with lower cortisol
production and higher heart rate variability
(showing higher parasympathetic activity)
 Optimistic people are, on average, healthier
and live longer than pessimistic people
 Optimistic people have higher levels of life
satisfaction

26.  Poor self-esteem has
debilitating effects:
◦ Increased levels of cortisol
◦ Inability to regulate cortisol
levels under stress
◦ 12-13% loss of hippocampal
volume

27.  Improve sleep quality and quantity
 Have a good social support system
 Maintain a positive outlook on life
 Maintain a healthy diet
 Avoid smoking
 Regularly exercise – moderate activity
 Build positive self-esteem
 Learn successful stress management

28.  McEwen, B.S. Protective and damaging effects
of stress mediators: central role of the brain.
New England Journal of Medicine. 1998, 338:
171-179

29. Q&A
Robin Donaldson,
rdonaldson@nationalsafeplace.org