Slide 1 The Role of Experience on the Developing Brain Barb Jackson, Ph.D. Director, Education & Child Development Munroe-Meyer Institute University of Nebraska Medical Center Omaha, NE USA The purpose of this presentation is to provide parents an understanding of the structure of the brain and how their experiences with their young infant/child can affect the development of the brain. Slide 2 Slide 3 The brain is a work in progress, designed to be adjusted and fine tuned throughout life. Recent research has shown us that the brain truly is a work in progress and the interactions of young children in their environment adjust and fine tune the intricacies of the brain. Shore, 1997
Slide 4 Show a video excerpt that illustrates a baby and adult interaction. Talk about how they will begin to discover how interactions influence the developing brain (optional). Slide 5 Brain Development. What is the structure? How does it work? Why are we interested in the brain? Let s learn a little bit about brain development. The brain is part of the central nervous system that is contained within the cranium. Here are a few facts about the brain.it weighs 3 pounds. At birth it is about 1/3 size and by 3 it is 90% the size of the adult brain. The next section of this presentation will describe: (a) technologies that have unveiled new discoveries about the brain and (b) brain structures and function, and why we should be interested in studying this aspect of the brain.
Slide 6 Advances in Technology MRIs fmris PET Scans Advances in technology have really allowed us to understand the relationship between experience and brain development. Two primary medical advances have supported this discovery, they include Magnetic Resonance Imaging (MRI) and PET scans. MRIs has been available since the 1980's and are a valuable tool in obtaining two and three dimensional images of the brain. This information is converted into computerized images representative of the brain structure. Slide 7 Hearing Speaking Seeing Generating Words Rethinking the Brain: Early Childhood Brain Development-Presentation Kit, 1998. For Full presentation, or research book, Rethinking the Brain, please contact the Families and Work Institute at www.familiesandwork.org Positron emission tomography (PET) was developed in the 1980's. It is one of the first tools to depict brain function or metabolism. The images produced provide information related to blood flow and energy use in the brain reflecting neural activity. This PET shows the brain s response to a person reading. Slide 8 fmri TOMOGRAPHIC TRACER IMAGE KINETI RECONSTRUCTION C MODEL Rethinking the Brain: Early Childhood Brain Development- Presentation Kit, 1998. For Full presentation, or research book, Rethinking the Brain, please contact the Families and Work Institute at www.familiesandwork.org Functional magnetic resonance imaging (fmri) is a relatively new diagnostic tool that allows scientists to image actual brain activity rather than the structure alone. These images are of superior quality than the PET. Both the fmri and MRI are relatively expensive tools.
Slide 9 Neurons: The Building Blocks of the Brain Receive, analyze and transmit information Neurons are highly specialized cells and are the building blocks of the brain. Their primary function is to receive, analyze, and transmit information through the formation of connections. While there are different kinds of neurons with specialized functions, they all have similar features. The neuron has an elongated shape with four basic parts: the soma, an axon, dendrites, and synapses. In addition, there is a protective covering on some neuronal axons called myelin. The soma (or cell body) contains the nucleus of the cell. It is responsible for the regulation of basic cell properties essential for the health and survival of the neuron. The axon is the part of the neuron that is sometimes called the nerve fiber. The axon is where information travels in the form of a nerve impulse to reach other neurons. Dendrites are fibrous branch-like protrusions that extend from the soma and carry information (in the form of electrical impulses) toward the cell body. Whereas a neuron typically has only one cell body and axon, it may have up to 600 dendrites. Myelin is a whitish, fatty material which insulates and protects the axons from each other and significantly increases the transmission rate of impulses. A synapse is the space where communication occurs between the axon of one neuron and, most commonly, the dendrite of another neuron. One neuron can actually have thousands of these synapses, or connection sites, with other neurons.
Slide 10 The Child s Brain Is Unique Neurons are not yet fully insulated. Neurons are still moving into positions. Synapse development is exploding. The child s brain looks much different then the adult brain. The neurons are not fully insulated and there is rapid increase of synaptic development. In a newborn the brain is not fully grown and as a result there is space in the cranium. Shaking an infant with their large head and weak neck muscles results in broken vessels, swelling, and tears in the brain tissue due to little to no myelin. Slide 11 Pattern of Synaptic Development in the Child s Developing Brain Birth 6 years 12 years Synapse Development Look at the pattern of the synapse development that occurs across time. Although the actual number of neurons remain stable.. The synapses grow rapidly. By the end of first three years.. The brain develps twice as many synapses as it will need, approximately 1,000 trillion. Notice the decline in synapses by the time the child is 14 years old. Scientist call this Pruning. They suggest that what synapses are pruned is dependent on the experiences of the child. This explains why we have seen a sudden interest on the emphasis of the early years. Basically, research such as Chugani (1987) suggests that the brain has capacity to change in the first decade and both positive and negative experiences can influence that.
Slide 12 CAUTION! There is controversy about Critical Periods! REMEMBER, the brain continues to grow throughout adolescence and adulthood! Although there are significant changes that occur during the early childhood years there is controversy about the idea of critical periods and that all is lost by the time a child is six. The information that we have now suggests that the brain continues to grow and change throughout adolescence and adulthood. Slide 13 Structure of the Brain Now let s take a look at the structure of the brain and the general function of each part. Slide 14 Many people think that the toddlers brain looks like this.
Slide 15 Or that the parent brain looks like this. Slide 16 Major Structures of the Brain Cerebral Cortex Diencephalon Cerebellum Brain Stem Limbic System Now let s begin to explore what the brain actually looks like and how it functions. The human brain has many parts, which function together as an integrated whole. When learning about brain structure, it is often helpful to learn about four major areas including the cerebral cortex, diencephalon, cerebellum, and brainstem. An additional collection of structures that will be explored is the limbic system.
Slide 17 Cerebral Cortex: Frontal Lobe Higher intellectual reasoning Emotional expression and regulation, and Motor movements The cerebral cortex is what many individuals popularly think of when picturing the human brain and it is responsible for the higher level cognitive processes associated with memory, thinking, sensations, vision, hearing, speech, and personality. The primary functions related to the frontal lobe are:.higher intellectual reasoning.emotional expression and regulation, and.motor movements. Located in the frontal lobe is the primary motor cortex, which as the name implies, is highly involved in voluntary motor movement. The Broca s motor speech area, which is also in the frontal lobe, is responsible for mouth movements during speech production. Slide 18 Cerebral Cortex: Parietal Lobe Sensory Information To introduce this section have a quarter and have someone close their eyes and see if they can guess what they have. You are now using the Parietal lobe..one important parietal lobe function is the analysis of body sensory data. Sensory receptors (e.g., for pain, pressure, and temperature) send impulses to this area of the brain. Posterior to this is an area is called the somatosensory association area. This area is highly specialized for skin sensations and makes interpretations of the sensations such as reaching into your pocket and being able to discern by touch.
Slide 19 Cerebral Cortex: Occipital Lobe The occipital lobe processes vision and matures very early. Visual images are processed Slide 20 Cerebral Cortex: Temporal Lobe Specializes in auditory perception and language Analyzes auditory information that enable recognition of whole words The temporal lobe is an area of the brain that is responsible for the detection and analysis of auditory stimuli. In most persons, the superior segment of the left hemisphere is specialized for the comprehension of language and verbal memory. If damaged, the ability to understand spoken or written language may be impaired, so that one might no longer be able to glean the conventional linguistic meaning from stimuli taken in from the sensory apparatus. If the right superior portion of the temporal lobe is damaged, comprehension of affective language components may be impaired, so that the emotional tone in a message will be missed. In summary: areas of the cortex allow the brain to: *receive, categorize, and interpret sensory information, *make rational decisions *activate behavioral responses
Slide 21 Diencephalon Hypothalamus Thalamus The diencephalon consists of two parts, the thalamus and hypothalamus. The thalamus is concerned with functions associated with sensation, movement, and relaying information from one part of the CNS to another. It receives sensory information from all senses except smell (olfactory information travels directly to the cortex), then organizes and routes the information to the cerebrum (where sensation are felt ). It also helps to associate sensations with emotions. The hypothalamus is located inferior to the thalamus and includes the pituitary gland. Despite its small size, it is responsible for a variety of diverse functions. These include: *regulation of body rhythms (such as mental alertness, mood change, sleep cycles, and hormone secretion); and *stimulation of several internal organs in response to emotional experiences.
Slide 22 Links to Neurological Problems Phantom pain Ringing in the ear Parkinson s Disease Lauerman (2000) suggest that there are many disorders that are associated with the thalamus. These disorders include phantom limb pain, ringing in the ears, depression, as well as Parkinson s disease. Rezai (2000) has been implanting brain pacemakers into the thalamus of patients with disorders such as Parkinson s disease. The purpose of the pacemaker is to help reestablish the rhythms that were disrupted due to the imbalance of neurotransmitters. In the case of Parkinson s disease, the patients showed a decrease in hand tremors when the pacemaker was on. Slide 23 Example Links affective experience with physical reactions. Anger Insomnia Loss of appetite The hypothalamus helps to translate affective experiences due to its links with the higher neocortical structures. These may include translating experiences involving anger, apprehension, and disappointment into physical reactions like insomnia, loss of appetite or deviant hormone patterns (Pathology, 1990). Many view the hypothalamus as the bridge between the body and the mind: the physical influences on the mind as well as the mental effects on physical symptoms.
Slide 24 Cerebellum The cerebellum contains more than half of the brain s neurons, suggesting its importance for the brain s overall functioning. Slide 25 Cerebellum Involuntary movement Balance Posture and eye movements Long term memory It is responsible for the coordination of involuntary (i.e., unconscious) movement and conditioned reflexes, which includes muscle tone regulation, coordination, maintenance of equilibrium (balance) and posture, and eye movements. Overall, it helps to produce smooth coordinated movements, maintain balance, and sustain normal postures. The cerebellum plays an important role in body movement, and its functioning is significantly affected by alcohol (which explains why persons who are intoxicated often display impaired coordination and slurred speech).
Slide 26 Brain Stem The brainstem consists of 3 primary parts, the midbrain, pons and medulla oblongata. Pons Mid-Brain Medulla Oblongata The midbrain is largely made up of axons, which enable the cerebrum to communicate with the lower brain structures. It contains important motor and sensory nuclei. Pons is composed primarily of sensory and motor fiber tracts and serves to connect the upper and lower CNS centers. Medulla Oblongata has the reflex centers for coughing, vomiting, swallowing, and sneezing. Slide 27 Limbic System In general the limbic system serves three primary functions including: Hypothalamus Olfactory Bulb Amygdaloid Nucleus of Basal Ganglia Fornix Thalamus Cingulate Gyrus of Cerebrum Key to emotional development Links conscious, intellectual functions: with the cerebral cortex autonomic functions of brain stem *Establishing emotion states and related behavioral drives, *Linking conscious, intellectual functions of the cerebral cortex and autonomic functions of the brain stem, *Facilitating memory storage and retrieval.
Slide 28 Emotional Development Emotions are set by the limbic system and prefrontal lobes Limbic system forms an emotional blueprint for later use Prefrontal lobes regulate emotional responses Both lobes are developed and connected early in life (8-18 months) Florida Starting Points Initiative, 1998 Both the limbic system and prefrontal lobes are related to emotions. There is a strong connection between the two areas of the brain, beginning early in the infant s development. Slide 29 Emphasis on the Early Years Brain has capacity to change in the first decade Enriched environment can increase the number of synapses Negative experiences can be more detrimental Review that the brain is plastic, especially in the first years of life. Both positive and negative experience can affect the number of synaptic connections that are either strengthened or pruned. Slide 30 Relationships Strong secure attachments to nurturing caregiver provides a protective biological function and helps to buffer later stress! Research has found that secure attachment provides a protective biological function and helps to buffer later stress. Neuroscience has provided us with more specific information on this.
Slide 31 Enriched or Deprived: Environment s Influence on Brain Development Use it or Lose it! What influences whether synapses are pruned or not? EXPERIENCE! Experience plays a role in what connections are kept and those that are discarded. Many refer to this as the use it or lose it process. Signals are strengthened with experience. As these connections become established through experience, they eventually become exempt from elimination. Slide 32 Positive Impact of High Quality Child Care Increased IQ scores Improved rate of brain processing information Ramey & Ramey, 1996 Ramey and Ramey (1996) also found that providing an enriched learning environment through an intensive, high quality program for young children who were at risk for developmental delay resulted in significant increases in IQ scores. PET scans (which measure brain activity) of these children at 12 years of age, demonstrated that their brains processed information at a more efficient rate than those of the control children. This suggested that positive behavioral changes (i.e., increased IQ scores) were underscored by an increase in synaptic connections between brain cells.
Slide 33 Deprived Environments Negatively Influence Development Decreased IQ Slower EEG maturation rate Otero, 1996 Poverty and cultural disadvantage were found to be factors in preschool children s brain activity in Mexico. Children who were at high environmental risk demonstrated a slower EEG maturation rate (Otero, 1996). Slide 34 What happens to a baby who is stressed?? Cortisol and adrenaline are released in response to stress Cortisol reduces # of synapses Adrenaline increases blood pressure and heartbeat and tightens muscles Gunnar, 1996 There is growing concern about what happens to babies that are stressed. Neuroscience research has found that cortisol and adrenaline are released in response to stress. If you think about it these important chemicals are helpful to someone who is in a stressful situation as they increase the blood pressure and heart beat, and tighten your muscles so that you are more prepared to act. However, there are negative responses to chronic stress in which cortisol is continually released. Research shows that cortisol reduces the number of synapses in the brain.
Slide 35 What does research tell us? Children exposed to constant stress, adrenaline does not subside = hyperaroused state. Perry, 1993 Baboons exposed to constant stress had major shrinkage in their hippocampusrelated to learning and memory. Sapolshky, 1996 Perry (1993) identified that when children are exposed to constant stress, the adrenaline does not subside. As a result they continue to be in a hyperaroused state and are more reactivate to situations. In addition, animal research showed that baboons that are exposed to constant stress had a major shrinkage in their hypocampus which is related to learning and memory (Sapolshky, 1996). Slide 36 What helps buffer stress? Babies who receive nurturing care in first year, are less likely to respond to minor stress and produce less cortisol Suggests that social emotional environment may help to shape the regulatory capacities of brain Dawson, et al., 1992 Research is showing us however that nurturing environments can help buffer stress. Promising news suggests that babies who received nurturing care can buffer the affects of stress. They are less likely to respond to minor stress and produce less cortisol. This has implications to parent educators as they are working with families. It is important to stress strategies that will help nurture their child. These will be discussed later in today s talk. Slide 37 What are the effects of depression on a developing brain? How do you think a mother s depression affects her interaction? Have the audience generate how they think that the mother s depression may affect her interaction with the child.
Slide 38 Depression s Impact on Young Infants Babies were more withdrawn and less active Babies had shorter attention spans and less motivation to master new tasks Reduced brain activity (40%) in left frontal region of the cortex - which is related to outwardly directed emotions Greatest period of risk - 6-18 months Dawson, et al., 1992 A study of 27 infants (11-17 months) found that infants who had mothers that were depressed showed reduced left frontal brain activity during playful interactions with their mother when compared to infants with nonsymptomatic mothers. These findings suggest that infant s experience, related to their emotional environment, influences brain development and subsequent behavior (less distress during separation) (Dawson, Kinger, Panagitides, Hill, & Spieker, 1992). Slide 39 Can the impacts of depression be changed? For many babies, once their mothers were treated for depression, the babies brain activity returned to normal. The exciting news based on this research is that for mothers who can be treated the babies brain activity returned to normal. Dawson, 1992
Slide 40 What are the implications for practice? Do the following exercise: Have everyone write down 4-5 ideas for infants and preschoolers- one idea per sticky. Then have them group the ideas into themes for each age group. Have a leader from each group review the theme with the whole group. Some ideas are: Maintain small child/caregiver ratios Improve our knowledge of children Respond to children's cues Slide 41 Growth of the Mind Consistent, nurturing relationships with the same caregivers, early in life, are the cornerstones of emotional and intellectual competence. Greenspan (1992) Engage in language activities Discuss the importance of consistency of caregivers and the implications for child care. For example, should there be primary caregivers for each child? Should child care minimize transition between age groups? Slide 42 Primary Care During infancy the most important relationships are with the primary caregivers. Through primary care, the caregivers and children begin to develop bonds of comfort, familiarity, trust, and love. The relationships between children and caregivers are deepened through the sharing of daily routines. It is very important that infants have a consistent adult figure in child care settings. This allows for the development of trust. Consistent daily routines are also important in order to provide consistent expectations for the infant.
Slide 43 Caregiver s Contribution to the Relationship Positive emotional climate Sensitivity and responsivity to the child s cues Enriched environmental experiences Appropriate developmental activities As caregivers, it is important to provide a positive, nurturing climate for the children in your care. It is necessary to be sensitive to the unique cues of each of the children and be responsive to those cues, provide appropriate developmental activities and enriched environments. Slide 44 The Responsive Process Watch Act Adapt Simply, this is how you can incorporate a responsive process. Be an active observer of the child, act based on the cues of the child, and adapt your play to meet his emotional needs and developmental level. Slide 45 You can make a difference in a child s life! Hopefully today s presentation has helped you to understand the importance of your role in each child s development, as well as their developing brain.
Slide 46 References Chugani, H. T. (1987). Positron emission tomography study of human brain functional development. Annals of Neurology, 22 (4): 487-497. Dawson, G., Kinger, L. G., Panagitides, H., Hill, D. & Spieker, S. (1992). Frontal lobe activity and affective behavior of infants of mothers with depressive symptoms. Child Development, 63, 725-737. Florida Starting Points Initiative (1998). Maximizing Nebraska s Brain Power: We need to use it or lose it. Greenspan, S. (1992). Infancy and Early Childhood: The practice of clinical assessment and intervention with emotional and developmental challenges. International Universities Press, Inc., Madison, CT. Gunnar, M.R. (1996). Quality of care and the buffering of stress physiology: Its potential in protecting the developing human brain. University of Minnesota Institute of Child Development. Slide 47 References, cont. Otero, G. (1996). Poverty, cultural disadvantage and brain development: A study of pre-school children in Mexico. Electroencephalography and clinical neurophysiology, 102, 512-516. Perry, B.D. (1996). Incubated in terror: Neurodevelopmental factors in the cycle of violence. In J. D. Osofsky (Ed.) Children, youth, and violence: Searching for solutions. NY: Guildford Press. Ramey, C. T., and Ramey, S. L. (1996). Prevention of intellectual disabilities: Early interventions to improve cognitive development. Birmingham: University of Alabama Civilian International Research Center. Shore, R. (1997). Rethinking the brain: New insights into early development. Families and Work Institute. New York, NY.