Infant Brain Development Complex Dynamic

Infant Brain Development Complex dynamic processes underlie the development of various functionalities of the infant brain and its maturation into an adult brain. Today, neurologists have concurred that both nature and nurture play a significant role during the initial years of development of the brain. Advancements in neuroimaging techniques including the various refinements in MRI and optical tomography have made possible the focused study of the various developmental stages of the brain in an infant. Healthy interactions with the child by touching, talking, playing, smiling, etc.

help to develop the functionalities of the brain to the fullest potential. Early years of parenting are crucial for the healthy development of a child's Brain and the effects last a lifetime. Introduction Brain development is a protracted process that continues through adolescence. Understanding the complexities involved in the development of the human brain from the most primitive neural structure or the neural tube, which forms in the first weeks of pregnancy to the complete adult brain structure with all its various functional regions intrigues neuroscientists around the world.

Born with more than 100 billion brain cells, which far exceed the number of stars in the Milky Way galaxy, the infant brain is one of the marvels of creation. Even more intriguing is the fact that each one of these neuronal cells is capable of forming connections with 15,000 other neighboring cells, which shows the complexity of the working mechanism of the brain.

[Sean Brotherson] Brain imaging studies which are the main tools in the study and understanding of human brain have helped neuroscientists unearth some of these complexities over the last few decades. A brief overview of the infant brain growth and its developmental stages and a discussion of the important tools that are used in studying the brain would give some insight into the topic Infant Brain Development Infant brain refers to the developmental stage of the brain from the time of birth to the first year of the baby.

This period is a very important stage in brain development and represents a unique phase of growth. Rapid brain development in the form of a rapid multiplication of neurons and the supporting glial cells is witnessed at this stage. There is also a proliferation of synapses or connections between neurons that communicate information. The actual sequence of brain development is genetically programmed and the brain maturation occurs from the lower brain regions to the higher regions.

[Nelson & Bloom, 1997] Most of the neuronal growth occurs during the early postnatal period and it is also during this time that neuronal migration occurs within the brain. One of the first changes in brain architecture that is observed in the postnatal period, particularly in the first few weeks after birth, is the increased metabolic activity in the brain stem and the sensory motor cortex region.

Since the brain stem region controls the vital aspects such as heart rate, breathing function and other reflex actions of the body, this region of the brain assumes priority. Though the brain stem region is well formed at birth, it continues to grow during the first few weeks and this region is also responsible for the development of the emotional and social development.

[Sean Brotherson] Between 6 months and 1 year of an infant, the frontal cortex region shows significant metabolic activity indicating the development of higher cortical functions such as memory, concentration, language etc. A child's vision development continues into the first year of its life. During this period, the number of neurons as well as the number of connections in the primary visual cortex region of the Child's brain is observed to be literarily twice that observed in a completely mature adult human brain.

[Joan Styles] However, the important point to be noted is that external visual stimulus is very essential for the successful completion of the primary visual cortex circuitry. Animal studies have confirmed that the lack of visual stimulus could irreversibly alter the functional organization of the neuronal cells leading to specific functional deficits. For instance, one early animal study by Hubel and Wiesel (1979) showed that completely blocking one eye of a kitten lead to permanent vision deficit in that eye.

Thus the very first year is critical in the development of visual acuity in a child. A child should be exposed to various colors, shapes and objects at varying distances in order to establish the visual cortical circuitry. [Sean Brotherson] It is also noticed in studies on blind people that plasticity of the infant brain allows for reorganization of the cortical regions to perform different functions.

For instance, in blind children it was observed that the neurons in the primary visual cortex region that are not used for visual purposes, got recruited by the primary auditory cortex that serves the hearing function. Functional MRI studies have confirmed this reorganization of the cortex [Joan Styles] One recent study has confirmed the importance of proper parental care and interaction during the first year of the baby's life.

The study by Miguel et.al (2006) reported that depressed and withdrawn mothers negatively affect the emotional and behavioral development of the infant. The researchers of this study used EEG recordings to assess the brain activity pattern among infants with depressed and non-depressed mothers. There was a significant difference in the EEG recordings between the two groups in that infants with depressed mothers with 'withdrawn interaction style' exhibited greater right frontal EEG activation compared to infants with non-depressed mothers with active interaction style who exhibited greater left frontal EEG activation.

This asymmetry in EEG profile is attributed to the specific neural activity corresponding to 'behavioral approach' and 'behavioral withdrawal'. A greater right shift corresponded to inhibitor behavior, negative stimulus, poor emotional regulation, etc. Thus maternal depression negatively affects infant brain development and infant behavior. [Miguel et.al, 2006] Brain Study Tools Brain researchers rely on imaging tools to understand the structure and the functional aspects of the brain. Brain imaging has developed a long way since computerized axial tomography (CAT) was discovered in the early 1970's.

The 1980's saw the development of a new imaging tool, the Positron Emission Topography (PET). PET and SPECT involve ionizing radiation and hence they are not advisable for infants. Immediately after that came the Magnetic Resonance Imaging (MRI) developed by Peter Mansfield and Paul Lauterber, which revolutionized brain study. The MRI being non-invasive and with no radiation hazards immediately became the standard for neuroimaging.

Also in the years that followed, many refinements were done to MRI and it was soon possible to study brain hemodynamics and brain structure using the Functional Magnetic Resonance Imaging (fMRI) [Columbia University] Cranial Ultrasound' is a routinely used screening device for new born babies to identify any complications in the brain including brain fluid build up, hemorrhage or other infections in the brain. This ultrasound study can only be used in babies below 18 months of age, as the sound waves cannot penetrate once the cranial bones are completely closed.

[Alan Sprigg] Recently, a new, less invasive, non-ionizing, and easy to access imaging device for infants, known as the Optical tomography has been developed. This technology involves the use of near infrared light across the brain and measurement of the transmitted light. Apart from providing 3D images of blood volume and oxygen levels, the technology is also useful in the dynamic study of the brain in response to external sensory stimulus.

Studies using Optical tomography have shown region specific oxygen consumption during the first 12 months which agree with earlier test results using PET and SPECT. Optical tomography is particularly useful because of its ease of use in infants (can be used in an ICU setting) and its effectiveness in studying the neurophysiological processes of the infant brain. [Jeremy C. Hebden, 2007] Conclusion Infant brain development is an important area of study for neuroscientists.

The complex dynamic processes that underlie the development of the various functionalities of the infant brain and its maturation into an adult brain continue to be studied by researchers working to.