SLIDE 1 The I m pact of Early Experiences on Brain and Behavioral Developm ent
Nathan Fox, Ph.D.
Distinguished University Professor, University of Maryland Mem ber, National Scientific Council on the Developing Child
Wisconsin Family I mpact Seminar March 19, 2019
SLIDE 2
Three Core Concepts of Developm ent
1 2 3
Brain Architecture is Established Early in Life and Supports Lifelong Learning, Behavior, and Health Stable, Caring Relationships and “Serve and Return” Interaction Shape Brain Architecture Toxic Stress in the Early Years of Life Can Derail Healthy Development
SLIDE 3
Experiences Build Brain Architecture
SLIDE 4 Brains are built over time, starting in the earliest years
- f life. Simple skills come
first; more complex skills build on top of them.
Brain Architecture Supports Lifelong Learning, Behavior, and Health
Cognitive, emotional, and social capabilities are inextricably intertwined throughout the life course. A strong foundation in the early years improves the odds for positive outcomes, and a weak foundation increases the odds of later difficulties.
SLIDE 5 The Ability to Change Brains Decreases Over Tim e
Source: Levitt (2009)
Birth 1 0 2 0 3 0 Physiological “Effort” Required to Enhance Neural Connections Norm al Brain Plasticity I nfluenced by Experience
Age ( Years)
4 0 5 0 6 0 7 0
SLIDE 6 Neural Circuits are W ired in a Bottom -Up Sequence
FI RST YEAR
1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9
Birth ( Months) ( Years) Sensory Pathw ays ( Vision, Hearing) Language Higher Cognitive Function
Source: C.A. Nelson (2000)
SLIDE 7 birth 6 years 1 4 years
Experiences Shape Brain Architecture by Over-Production Follow ed by Pruning
7 0 0 synapses are form ed per second in the early years
SLIDE 8 Sensitive Periods
- Are limited time periods during which
the effect of experience on the brain is particularly strong
- Allow experience to instruct neural
circuits to process information in an adaptive way
- Provide information that is essential
for normal development and may permanently alter performance
SLIDE 9 Early W indow s of Experience Shape Brain Function
Motor / Language Higher Cognition Sensory Birth
environment critical period genes behavior
in utero adulthood
Figure courtesy of Takao Hensch
SLIDE 10
Lorenz and I m printed Ducklings W alking After Him
SLIDE 11 Hubel and W eisel: Classic Studies on Early Experience and Sensitive Periods
Monocular deprivation in early infancy led to deficits in brain organization in visual cortex
SLIDE 12 Source: Lewis & Maurer (2005)
Studies of I nfants Born w ith Bilateral Cataracts—Tim ing of Surgical Rem oval
SLIDE 13 Source: Werker & Tees (2005)
The Tim ing and Nature of Experience w ith Language Affects Perception of Different Languages
Before 9-10 months of age, infants can discriminate the sounds of all languages. By the end of the first year of life, they are able to discriminate only the language(s) they hear in their environment.
SLIDE 14
I nteraction Shapes Brain Circuitry
SLIDE 15 Young children naturally reach
- ut for interaction through
babbling, facial expressions, and gestures, and adults respond in kind.
Serve & Return Builds Brains and Skills
These “serve and return" interactions are essential for the development of healthy brain circuits. Therefore, systems that support the quality of relationships in early care settings, communities, and homes also support the development of sturdy brain architecture.
SLIDE 16 Barriers to Educational Achievem ent Em erge at a Very Young Age
1 6 m os. 2 4 m os. 3 6 m os.
Cum ulative Vocabulary ( W ords)
College Educated Parents W orking Class Parents Low SES Parents
Child’s Age ( Months)
2 0 0 6 0 0 1 2 0 0
Source: Hart & Risley (1995)
4 0 0 8 0 0 1 0 0 0
SLIDE 17 An “Air Traffic Control System ” in the Brain
Executive functioning is a group of skills that help us focus on multiple streams of information at the same time, set goals and make plans, make decisions in light
revise plans, and resist hasty actions.
- a key biological foundation of school readiness, as
well as outcomes in health and employability
SLIDE 18 W hat are Executive Function Skills?
I nhibitory Control — filter thoughts and impulses to resist temptations and distractions Cognitive Flexibility — adjust to changed demands, priorities,
W orking Mem ory — hold and manipulate information in our heads
- ver short periods of time
SLIDE 19 Higher Childhood Self-Control Predicts Better Adult Health
Adult Health Outcom es Childhood Self-Control 5 4 3 2 1 High Low
Poor Physical Health Index Substance Dependence Index Source: Moffitt, et al. (2011)
Good health Poor health More substance abuse Less substance abuse
SLIDE 20 50% 40% 30% 20% 10% High 5 4 3 2 1 Low
Adult Criminal Conviction
Childhood Self-Control
Source: Moffitt, et al. (2011)
Higher Childhood Self-Control Predicts Less Adult Crim e
Adult Crim inal Convictions
SLIDE 21
Toxic Stress Derails Healthy Developm ent
SLIDE 22
Toxic
Prolonged activation of stress response systems in the absence of protective relationships.
The Biology of Adversity: Three Levels of Stress
Tolerable
Serious, temporary stress responses, buffered by supportive relationships.
Positive
Brief increases in heart rate, mild elevations in stress hormone levels.
SLIDE 23 Learning how to cope with moderate, short-lived stress can build a healthy stress response system.
Relationships Buffer the Effects of Stress
Toxic stress—when the body’s stress response system is activated excessively—can weaken developing brain architecture. Without caring adults to buffer children, toxic stress associated with extreme poverty, neglect, abuse, or severe maternal depression can have long-term consequences for learning, behavior, and both physical and mental health.
SLIDE 24 Persistent Stress Changes Brain Architecture
Source: C. Nelson (2008)
Normal Chronic stress
Prefrontal Cortex and Hippocampus
Bock et al. (2005) Typical - neuron with many connections Neuron damaged by toxic stress – fewer connections
SLIDE 25 In 1995-1997, Kaiser Permanente in California conducted a survey of adult patients in which they were asked to identify a range of adverse childhood experiences (abuse, neglect, household challenges). Researchers later found that the cumulative number of these experiences in childhood was related to adult health and disease.
Adverse Childhood Experiences ( ACES) Study
Source: Felitti et al. (1998)
SLIDE 26 Adverse Childhood Experiences and Adult Cardiovascular Disease
0.5 1 1.5 2 2.5 3 3.5 1 2 3 4 5,6 7,8
Number of ACEs
Source: Dong et al. (2004)
Odds Ratio
SLIDE 27
Neglect is Com m on
SLIDE 28 Effects of Profound Neglect on Brain Developm ent
Why neglect is bad for the brain
- Brain expects input it doesn’t receive, so
its wiring is altered
- Particularly egregious if experiences
expected to occur during a sensitive period fail to occur (e.g., patterned light, sound, caregiving)
SLIDE 29 Source: Nelson (2008); Marshall, Fox & BEIP (2004)
Extreme Neglect Positive Relationships
Extrem e Neglect Reduces Brain Pow er
SLIDE 30
There Are No Magic Bullets
Positive relationships and quality learning experiences can be promoted both at home and through a range of evidence-based parent education, family support, early care and education, and intervention services. A balanced approach to emotional, social, cognitive, and language development will best prepare children for success in school and later in the workplace.
SLIDE 31 Effectiveness Factors for Early Care and Education Program s for Children From Birth to Age 5
- Qualified and well-compensated personnel
- Small group sizes and high adult-child ratios
- Language-rich environment
- Developmentally appropriate “curriculum”
- Safe physical setting
- Warm and responsive adult-child interactions
SLIDE 32 Science Points Tow ard a Tw o-Tiered Approach to Reducing Disparities
Basic health services and good quality early care and education can promote healthy development and early detection of problems in all children. Targeted services for children experiencing tolerable or toxic stress can reduce disruptions of the developing nervous and immune systems that lead to later problems in learning, behavior, and health.
TARGETED SERVI CES HEALTH SERVI CES & EARLY CARE AND EDUCATI ON
SLIDE 33
- Significant brain development occurs in the first
years of life
- Healthy brain and behavioral development
require positive, sensitive, and responsive caregiving
- Toxic stress can derail healthy brain and
behavioral development
- Providing support to families, good
compensation to early childhood teachers, and good quality and basic health care services can go a long way toward enhancing positive
Takeaw ays
SLIDE 34 www.developingchild.harvard.edu
Nathan Fox Distinguished University Professor University of Maryland
fox@um d.edu
YOUR INSTITUTION’S LOGO
