Early Brain and Child Development:
Effects of Early Childhood Adversity
and Toxic Stress, Resultant
Language and Reading Delays
Eileen C. Vautravers, M.D.
www.ne-da.org
402-434-6434
2
From Neurons to Neighborhoods: The
Science of Early Childhood Development,
2000 (Nat. Acad. Press)
Editors, Jack Shonkoff and Deborah
Phillips
The Center on the Developing Child,
Harvard University
(www.developingchild.harvard.edu)
National Scientific Council on the
Developing Child, Working Papers #1
through #12
Core Concepts in Early Brain
and Child Development
1. Child development is foundation for
2.
3.
4.
5.
community and economic development.
Brains are built over time.
Brains and developing abilities are built
“bottom-up”.
“Serve and return” interactions build
healthy brains.
Genes, environment and experiences
shape brain architecture.
Core Concepts in Early Brain
and Child Development (cont)
6. Cognitive, emotional and social
development rely on each other.
7. Early childhood adversity and toxic stress
can damage brain architecture.
8. Positive parenting buffers toxic stress.
9. Creating right conditions for early child
development is more effective and less
costly.
Eco-Bio-Developmental
Model of Human Health and Disease
Biology
Physiologic Adaptations
and Disruptions
The
Science of
Development
Life Course
Science
Ecology becomes biology, and together they
drive development across the lifespan (Ref 53)
Brains Are Built Over Time,
“Bottom-up”
A. Early experiences are foundation of
brain’s architecture.
1. Sturdy - sharp, stable, strong
2. Fragile - dull, disturbed, diseased
B. Proliferation
1. 700 new synapses per second
C. Pruning for efficiency
D. Sequential neural circuit development
E. Scaffolding
Serve and Return – Active
Ingredient of Experiences
A. Builds and strengthens brain architecture
B. Associated with stronger cognitive skills,
language development, fewer behavior
problems
1. Quality home environment related to early
cognitive & language development, IQ test
results and school achievement (Ref 1-10)
2. Positive childcare relationships associated
with better thinking and reasoning skills (Ref
1,6-7)
Serve and Return – Active
Ingredient of Experiences
C. Unreliable, inappropriate, or absent
interactions damage brain architecture.
1. Neglect causes more harm, such as
cognitive delays, executive function
impairments and disruption of body’s stress
response, than physical abuse. (Ref 11-13)
Genes, Environment and Experiences
Shape Brain Architecture
A. Genetics
1. Blueprint for brain development
2. Instructs properties of neurons and synapses
B. Environment
1. Influences quality of brain-building materials
2. Can alter brain’s genetic plan prenatally
3. Healthy – full genetic potential
4. Unhealthy – abnormal neuron properties and
aberrant synapses (Ref 14-16)
Genes, Environment and Experiences
Shape Brain Architecture
C. Experiences are child’s interactions with
environment.
1. Low-level, simpler circuits affected prenatally
(Ref 15)
2. Most potent effects postnatally when neural
circuits maturing (Ref 17-20)
3. Can alter genetic plan after neural circuit
maturation (Ref 18,21,22)
4. “Sensitive periods”, as in vision (Ref 23-24),
hearing (Ref 25), language (Ref 26)
Disparities in Early Vocabulary Growth
Professional
Families
1,116 words
1200
Vocabulary Size
1000
Working Class
Families
749 words
800
600
Welfare
Families
525 words
400
200
0
9
12
15
18
21
24
27
30
33
36
Age of child in months
Source: Hart, B. and Risley, T. R. (2003). “The Early Catastrophe: The 30 Million Word Gap by Age 3.”
Ref 52
Early Experiences Alter Gene
Expression, Shape Brain
A. Experience changes brain chemistry.
(Ref 33)
B. Genes altered in “sensitive periods” or
throughout life (Ref 34-39)
C. Epigenetic changes can be inherited.
(Ref 40-42)
D. Positive mastery experience causes
epigenetic changes essential for learning.
(Ref 43-45)
Early Experiences Alter Gene
Expression, Shape Brain
E. Emotional development biologically wired
into brain (Ref 46-50)
1. Adverse Childhood Experiences (ACE) prime
stress system to make hyper-responsive to
adversity. (Ref 51)
2. ACE acts as “signature” releasing genetic
predisposition for fear.
Adverse Childhood Experiences
1. Emotional, physical, sexual abuse
2. Emotional, physical neglect
3. Mother treated violently
4. Household substance abuse
5. Household mental illness
6. Parental separation or divorce
7. Incarcerated household member
Types of Stress Responses
A. Positive – brief increase in heart rate,
mild elevation in stress hormones (shots)
B. Tolerable – serious, temporary stress
response buffered by supportive
relationships (death and divorce)
C. Toxic – prolonged activation of stress
response in absence of protective
relationships (abuse, chronic neglect,
poverty, exposure to violence, parental
substance abuse or mental illness)
ACE and Toxic Stress
A. Brain vulnerability in early “sensitive
periods” (Ref 54-55)
1. Very young can develop debilitating anxiety.
(Ref 56)
B. Mechanisms for ACE changes in brain
1. Epigenetic “adaptations”
2. “Wear and tear” releases adrenaline and
cortisol
C. Amygdala detects whether stimulus,
person, event is threatening. (Ref 69-70)
ACE and Toxic Stress
D. Hippocampus links fear response to context of
event. (Ref 71)
E. Pre-Frontal Cortex (PFC) development with
Executive Function Skills
1. Impaired by high stress in animals (Ref 72)
2. Smaller volume in severe neglect in humans (Ref
73-74)
F. Neuroplasticity to stress
1. Early toxic stress results in overly reactive and slow
to shut down stress response. (Ref 57-58)
Cortisol Effects
A. Chronic elevation regulates gene
expression in neural circuits for stress
response, emotion and memory. (Ref 59)
B. Chronic elevation alters neural function
and brain structure in areas of learning
and memory. (Ref 60-61)
C. Elevated cortisol in economically
deprived children & exacerbated when
mother depressed (Ref 62-64)
Cortisol Effects
D. Abnormal cortisol production persists in
neglected children after moved to safe,
loving home. (Ref 65-66)
E. In animals, chronic elevation damages
hippocampus, affecting learning, memory
and stress response regulation. (Ref 67)
F. Chronic elevation also affects the
amygdala.
Ref 68
Effects of Toxic Stress on
Learning
A. Positive stress response strengthens
memory formation of emotional events
and contexts, blocks unlearning of fear
memory. (Ref 81-84)
B. Toxic stress can impair memory and
learning in non-threatening contexts. (Ref
85)
C. Toxic stress can form emotional
memories easily relived and more difficult
to forget. (Ref 86-87)
Effects of Toxic Stress on
Learning
D. Toxic stress causes generalization of
threat to safe contexts. (Ref 88-89)
E. Toxic stress builds brain architecture that
responds to lower levels of stress with
excessive anxiety & fear, causing lifelong
effects on mental health. (Ref 90). These
mental health effects can impair learning
and relating. (Ref 91)
Effects of Toxic Stress on
Learning
F. Toxic stress causes elevated brain
noradrenaline which alters activity of neurons in
PFC, causing cognitive control and learning
problems. (Ref 92-93)
G. Toxic stress affects Executive Function Skill
(EFS) system, the foundation for school
readiness and academic success. (Ref 94-95)
1. Preschoolers with stronger EFS perform better on
early math, language and literacy development
tests. (Ref 96-103)
Effects of Toxic Stress on
Learning
G. Toxic stress affects EFS (cont)
2. EFS in economically-deprived preschoolers
predicts kindergarten math and reading
achievement better than their earlier scores.
(Ref 104) – Same for behavior (Ref 105)
3. EFS connected with deep brain areas that
control stress response (Ref 106-108)
4. EFS system influences and is affected by
experiences & management of stress. (Ref
109-110)
Effects of Toxic Stress on
Learning
G. Toxic stress affects EFS (cont)
5. Toxic stress affects chemistry of brain
circuits and alters neurons in EFS system.
(Ref 111-114)
6. Toxic stress causes poor performance on
tasks involving working memory and shifting
attention. (Ref 115)
7. Early exposure to stressful environment
associated with deficits in working memory,
attention and inhibitory control (Ref 116-118)
Effects of Toxic Stress on
Learning
G. Toxic stress affects EFS (cont)
8. Toxic stress causes difficulty engaging EFS
even in safe environs. (Ref 119-120)
9. Lower socio-economic children have poorer
performance on working memory, cognitive
flexibility and inhibition, and altered prefrontal function between ages 7-12 years.
(Ref 121-125)
Ref 126
Types and Causes of Dyslexia
A. Primary dyslexia – absence of brain
wiring to left hemisphere posterior
reading systems
1. Genetically programmed error in
wiring
2. 40% chance a sibling, parent, child of
affected person will have dyslexia
3. 5%-6% chance child will have dyslexia if
parent/siblings don’t
Types and Causes (Cont)
A. Secondary dyslexia – lack of activation of
normal brain wiring for reading
1. Environmental deprivation
a) Economically disadvantaged
b) ESL students
c) Struggling readers
2. Poor school reading instruction
System for Reading
in Young Dyslexic
Brain Rewired by Evidence-Based
Phonologic Instruction
1. Functional MRI’s on young struggling
readers – left Broca’s area
2. One year of sequential, explicit,
multisensory reading instruction (OrtonGillingham based)
3. Repeat fMRI’s - emergence of left
posterior, right frontal and right posterior
reading systems
Brain Rewired by Evidence-Based
Phonologic Instruction (Cont)
4. Repeat fMRI’s one year after instruction
ceased – right frontal and right posterior
systems much less prominent, increased
left posterior systems; fMRI’s essentially
same as a non-impaired reader
5. Children had improved reading accuracy
and speed
Source: Sally Shaywitz, Overcoming Dyslexia, Alfred A. Knopf, New York, 2003
6. Multiple studies have confirmed results
Brain Repair after Intervention
Brain Rewired by Evidence-Based
Phonologic Instruction (Cont)
7. Both primary and secondary dyslexics
improve with accuracy and speed of
reading with appropriate instruction
8. Without appropriate instruction, primary
dyslexics can improve accuracy, but
remain slow. Secondary dyslexics
remain slow and inaccurate
Window of Opportunity
1. When evidence-based phonologic
remedial intervention begun in first grade,
expected reading disability of 12% to
18% is reduced to 1.6% to 6%
Source: Torgesen, J.K., “Avoiding the Devastating Downward Spiral. The Evidence that Early
Intervention Prevents Reading Failure”, 2004
2. When this intervention is delayed until
third grade, 74% of students continue
with reading difficulties through high
school
Source: American Academy of Pediatrics Technical Report, “Learning Disabilities, Dyslexia and Vision”,
March, 2011