SCIENTIFIC EVIDENCE FOR THE IMPORTANCE OF SUPPORTING DEVELOPMENT OF CHILDREN 0-3 YEARS Maureen Samms-Vaughan Regional Forum on Birth to Three St. Vincent
OUTLINE A Trajectory of Caribbean Childhood The Biology of Brain Development Practical Evidence for the Importance of 0-3 years (Regional and International) Intervention Evidence for ECD A Trajectory of Caribbean Childhood Conclusions : What does this mean for the Caribbean ?
A TRAJECTORY OF CARIBBEAN CHILDHOOD A group of children are born within months of each other in a Caribbean town At 3 years, they go to the same pre-school in their town The teacher finds the children diverse, but there are some striking differences.
WHY ARE THE CHILDREN DIFFERENT? Were some “born bad?” as we sometimes say in the Caribbean. NOT SO The Science of Early Childhood Development indicates that the first few years of life are critical to children’s health, development and behaviour and set the stage for adult health, education and behaviour All Children are born wired for feelings and ready to learn. It is the environment that we have created for them that determines who they become at 3 years AND for many years to come. What is the evidence for this?
THE BIOLOGY OF THE BRAIN
THE GROWTH OF THE HUMAN BRAIN The brain is the most rapidly growing of all organs during the first few years Average head size at birth (head circumference) is 35 cm. Two-thirds of brain size is achieved by 21/2 to 3 years Brain growth then occurs slowly but steadily until 18 years, when adult head size is achieved
BRAIN GROWTH THROUGH ADULT LIFE
04-039 Micro Structure of the Brain RECIPIENT Axon NEURON Synapse SIGNAL- Dendrite SENDING NEURON
DETAILS OF BRAIN GROWTH Neurons and connections that you are born with are responsible for basic functions of life, keeping the heart beating, breathing etc. Further increase in complexity of the brain is dependent on the young child’s experience . Two types of further brain growth: Differentiation into specialised brain cells. Increase in number of synapses
08-026 Importance of early experience I The stimuli that you encounter both pre- and post-natally as well as in adolescence and adulthood differentiate neuron function. Examples: sound, touch, vision, smell, thoughts and emotions Kolb, U Lethbridge
“THERE IS NO GOOD HEALTH DR. EARL WRIGHT WITHOUT GOOD MENTAL HEALTH” DIRECTOR MENTAL HEALTH
Importance of early experience II Average Number of Neurons in the Brain: 100 Billion . Number of Synaptic Connections at Birth: 50 Trillion Number of Synaptic Connections after a few months (20 times) : 1,000Trillion Kolb, U Lethbridge
You are the cells in your brain You are your brain. Your brain is not just produced by genes The cells in your brain are sculpted by a your experiences. The most important time for sculpting in brain development is in utero and the first few years of life. Kolb, U Lethbridge
Importance of Timing of Early Experience : Critical (Sensitive) Periods Research has also shown that the first 3-4 years are critical for the development of sensory pathways (hearing and vision), social and emotional development and the basic pathways for reading and mathematics. If these pathways are not adequately developed in the early years, tremendous human and financial resources must be expended to address deficiencies. Normal development is often not possible . Kolb, U Lethbridge
01-003 Human Brain Development – Language and Cognition Language Sensing Pathways Higher (vision, hearing) Cognitive Function -3 3 9 1 -6 0 6 4 8 12 16 Months Years AGE C. Nelson, in From Neurons to Neighborhoods, 2000.
`Sensitive periods ’ in early brain development “Pre - school” years School years High `Numbers’ Peer social skills Conceptualization Language Habitual ways of responding Emotional control Vision Hearing Low 1 2 3 4 5 6 7 0 Years Graph developed by Council for Early Child Development (ref: Nash, 1997; Early Years Study , 1999; Shonkoff, 2000.)
CONCLUSIONS FROM BIOLOGY The early years of life are important because the interactions that a young child has with his/her environment determines the structure of the brain Early experiences determine learning, behaviour and health Early experiences determine whether a child has a strong or fragile foundation to go into adulthood with
PRACTICAL EVIDENCE FOR IMPORTANCE OF BIRTH TO THREE
BIRTH TO THREE , LANGUAGE AND LEARNING
Early Child Development and Language Language development starts early: first 7 months Sets capability for mastering multiple languages Sets literacy and language trajectory
Vocabulary Growth – First 3 Years Word Exposure Vocabulary 1200 High Middle 600 Low 0 12 16 20 24 28 32 36 B. Hart & T. Risley, Meaningful Differences in Everyday Age - Months Experiences of Young American Children, 1995
04-146 Test of Language Development (TOLD) at Age 9 Can predict a child’s reading score at age 9 years from vocabulary at 3 years Correlation between vocabulary growth at Age 3 and TOLD at Age 9 : 0.74
READING SCORES BY NO. OF POSSESSIONS IN HOME: PRE-SCHOOL TO GRADE 3 (JAMAICA) 30 25 20 0 to 2 3 to 4 15 5 to 6 7 to 10 10 5 0 Pre-School Grade I Grade 3
09-033 BIRTHWEIGHT AND MATH 1958 Birth Cohort (UK) 0.2 0.1 Test Score 0 -0.1 -0.2 -0.3 -0.4 <2.5 2.5-3.0 3.01-3.5 3.51-4.0 >4.0 Birthweight (kg) Jefferis et al. 2002
LOW BIRTHWEIGHT AND READING (LA and Cuba) Birthweight Reading % Infants % Level 4 Low BW Grade 6 UNICEF 2008 UNESCO 2008 Cuba 5 51 Chile 6 29 Mexico 8 24 Brazil 8 22 Reading Levels: 1 (Low); 4 (High) UNESCO Adapted from UNICEF 2008 and UNESCO 2008
BIRTHWEIGHT AND SCHOOL SCORES 11-12 YRS (JAMAICA) *** LBW NBW *** 40 *** 30 20 10 0 Arithemtic Arithemtic Spelling Spelling Reading Reading Samms-Vaughan, 2002 *** p< 0.0001
BIRTHWEIGHT AND REASONING 11-12 YRS (JAMAICA) % LBW NBW 25 *** *** 20 15 10 5 0 Ravens Ravens PPVT PPVT Samms-Vaughan, 2002, *** p<0.0001
SUMMARY Children who get exposed to language in the first few years of life go on to have better reading ability in later childhood and adulthood Children of low birth weight, a birth vulnerability factor, have later learning and behaviour difficulties
BIRTH TO THREE AND PHYSICAL HEALTH
PHYSICAL HEALTH • Babies born small for age (not premature) have higher physical health risks as adults of: • Heart disease • High Blood Pressure • Type 2 Diabetes • Obesity • Vulnerability to Aging • Babies who are undernourished in the first few years of life have later learning difficulties
04-006 ECD Swedish Longitudinal Study and Adult Health Number of Adverse ECD Circumstances* 1 2 4 0 3 Adult Health Odds - Ratios General Physical 1 1.39 1.54 2.08 2.66 1 1.56 1.53 2.91 7.76 Circulatory Mental 1 1.78 2.05 3.76 10.27 * Economic, family size, broken family and family dissention Lundberg, Soc. Sci. Med, Vol. 36, No. 8, 1993
BIRTH TO THREE AND MENTAL HEALTH
STRESS AND THE DEVELOPING BRAIN (1) Stress systems are particularly malleable or “plastic” during the fetal and early childhood periods Early experiences shape how readily they are activated and how well the responses can be contained and turned off Stress responses that are activated too frequently or for prolonged periods in the absence of supportive systems (Toxic stress) are damaging to the brain.
STRESS AND THE DEVELOPING BRAIN (2) Toxic stress during this period affects the developing systems and result in systems that are hyper-reactive or slow to shut down when faced with threats This leads to increased risk of behavioural and physiological disorders: - Anxiety & Depression - Alcoholism & Drug Abuse - Cognitive & Memory Impairment - Cardiovascular Disease - Stroke - Diabetes - Infections
Sensory Experience in Early Life Promotes Positive Behaviours Rats, other animals lick pups Humans seek attachment In absence of attachment, infants self stimulate by rocking
A “Natural” Experiment: Romanian Orphan Adoption Children adopted into middle class homes after 8 months in the orphanages show at 11 years in contrast to children adopted early: 1. Abnormal brain development (small brain, low metabolic activity, abnormal EEG) 2. Social and cognitive problems (IQ loss) 3. High vulnerability to behavioural problems (ADHD, aggression, quasi-autism) Kolb, U Lethbridge
IMPACT OF CHILD ABUSE Physical damage to brain structure in areas responsible for thinking (cortex), processing memories and emotions (hippocampus), and responding to danger (amygdala). These regions are critical for learning. The hippocampus becomes smaller with chronic abuse. Changes in brain chemistry also occur. Increases the production of the stress hormone cortisol, and neurotransmitters such as epinephrine, dopamine and serotonin, the chemical messengers in the brain that affect mood and behavior, leading to depression and aggression. Abnormal EEG and seizures. Teicher, 1993, 1998
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