One-month-old Connor only dimly perceives the world around him. Just two months later, when he sees his mother’s beaming face or hears his father’s hearty laugh, he smiles with recognition. And by the time Connor reaches his first birthday, he’s starting to put one foot in front of the other and verbally communicate with his parents. Just what accounts for these significant changes?
“Infants first experience the world through primary sensory experiences: sound, sight, and touch,” said J. Christopher Edgar, PhD, a researcher in the department of Radiology at Children’s Hospital of Philadelphia and an associate professor of Radiology at the Perelman School of Medicine at the University of Pennsylvania. “Over time, infants begin to derive meaning from these sensory experiences, recognizing family members and gradually learning to recognize and eventually understand language, facial expression, and other aspects of their environment. As parents know, by 3-years-old, children understand much of what goes on around them. The changes in brain function and structure across maturation that make the above possible are poorly understood.”
With a five-year project grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development titled “Brain Structure and Function in Infants,” Dr. Edgar is conducting a longitudinal study that measures brain function and structure during infancy and early childhood and examines how these changes are associated with the behaviors that emerge during this period. Read more about it in our question and answer interview with Dr. Edgar, and find out how this “Babies’ Brains Change” research could help future studies identify differences in brain maturation in children with developmental disabilities, allowing for timely treatment before “critical periods of cortical development have closed,” Dr. Edgar noted.
Why is this important research to tackle?
Much of our current knowledge of infant brain development is based on data acquired in other species, often rodents. However, humans are unique in their ability to understand and use language, as well as many higher-order reasoning abilities. Therefore, animal models of brain development are not easily translated to human infants. Our study obtains measures of brain development in infants, examining single time point measures (How quickly does sensory information enter the brain of a 6-month-old?) as well as rate-of-change measures (How much faster does a 2-year-old process auditory information than a 1-year-old?). By understanding how the brain typically matures, future studies can explore how brain maturation differs in children with developmental disabilities — for example, autism spectrum disorder, specific language impairment, intellectual disability. Early identification of atypical brain development in infants has the potential to lead to early intervention, thus allowing us to initiate treatment before critical periods of cortical development have closed.
Tell us about the project’s goals, a little bit about the current study design, and how you plan to accomplish this research?
For this longitudinal study, typically developing infants between 2- and 6-months-old are recruited to participate in developmental milestone testing. Measures of brain function with magnetoencephalography (MEG) and measures of brain structure with magnetic resonance imaging (MRI) are also obtained. MEG records the electrical signals in the brain, thus giving us information on the timing and strength of the brain’s responses to incoming auditory, visual, and tactile information. MRI provides detailed information on the structure of the brain. Children will return every five months for repeat testing until they reach 22- to 26-months-of-age. This will allow us to track how the brains of typically developing infants develop.
Why do you think the Eunice Kennedy Shriver National Institute of Child Health and Human Development was/is so excited about your research project?
Little is known about the infant brain, and longitudinal infant brain imaging studies are logistically quite difficult. As a result, most multiple time-point brain imaging studies use only one modality (EEG, MEG, or MRI) and have few participants. CHOP is unique in having the infrastructure to support a large sample infant study (willing participants, clinical staff, neuroimaging staff, and research assistants) as well as the needed noninvasive brain imaging technology. We are recruiting approximately100 infants and collecting MEG and MRI data. By combining information on brain function and structure at multiple time-points during development, we can obtain a more comprehensive picture of typical brain maturation than previous studies.
Why is CHOP Research Institute an ideal place for you to accomplish these research goals?
Across the last 10 years, CHOP researchers have worked to develop research teams devoted to better understanding brain function and structure in a population typically underserved in brain imaging studies — infants and children. With a growing focus on brain development in infants, CHOP researchers recently developed an infant MEG system — one of the few in the world — and established the infrastructure needed to conduct MEG and MRI brain imaging studies. It is our hope that this study and other brain imaging studies at CHOP will pave the way toward new targeted treatments in disorders such as autism spectrum disorder, attention deficit disorder, dyslexia, and other intellectual and developmental disorders.
How did this become one of your research interests, and why do you enjoy your work?
As an undergraduate philosophy major, I became interested in “the brain.” After reading many books on the brain, I started working in a research center in Albuquerque, N.M., that used brain imaging to study schizophrenia. Twenty-five years later, I am still very interested in understanding the brain, and now with two kids of my own, my interests are on brain development. Aside from infant brain development just being interesting, my research with adults has shown me that abnormal brain activity in neurodevelopmental disorders cannot be understood until we understand typical brain development. Thus, with my colleagues, I’m now focusing on “the beginning” to understand what comes later.
Check out our CHOP_Research Instagram account to see Dr. Edgar and members of the MEG lab start the new year in style with their “Babies’ Brains Change” t-shirts!