Developmental Disorders Research

Developmental brain disorders such as autism and dyslexia are common conditions that are typically diagnosed in childhood, but which can also lead to lifelong impairments.

Many psychiatric disorders are thought to have their origins in early life, even if they are not diagnosed until many years later. We now understand that these conditions involve a complex interplay of genetic and environmental risk factors, but their precise causes are still not known. Current treatment options are often inadequate, and there is an urgent need for new and better therapies.

Developmental disorders are an important target for research at the McGovern Institute. One goal is to identify children at risk as early as possible. For most of these conditions, earlier intervention is associated with better outcomes. Because these conditions are heterogeneous, another goal is to identify different subsets of individuals for which different treatments may be effective. Finally, a deeper understanding of the neural basis of these disorders may allow the design of new therapies, whether behavioral or pharmacological, that will produce better outcomes.

A major focus of the work is on pediatric neuroimaging, including large-scale studies of autism and dyslexia. Along with clinical populations, we also study the development of brain function in normally developing children and adolescents. Understanding the developmental origins of human capacities such as memory, language, and emotion will provide a framework for understanding the basis of developmenis specifically activated by written words in the subject’s native language but not an unfamiliar language -- a clear demonstration of how education can shape the brain. Understanding how the brain processes spoken and written language will provide the essential framework for understanding the basis of language learning impairment and dyslexia.

RESEARCH ON BRAIN DEVELOPMENT AND PLASTICITY

Martha Constantine-Paton studies how the mammalian brain becomes wired in response to experience. This is a fundamental question for normal development and is also relevant to a range of brain disorders, many of which are thought to have their origins during early development long before they are diagnosed. Constantine-Paton’s work focuses specifically on the visual system, particularly the changes that occur during the critical period following eye-opening when the brain first responds to visual experience. The principles that emerge are also relevant to other senses and to higher cognitive functions such as language acquisition.

Michale Fee is studying the neural basis of song learning in birds. Like human infants learning to speak, young birds learn their song by imitating adults. This is a process of trial and error, in which young birds go through a period of babbling, before the song crystallizes into its mature song. Fee and colleagues have recently identified a circuit in the brain that drives the variable, exploratory vocalizations that form the basis for this trial-and-error learning.

Yingxi Lin studies the development of inhibitory connections, which act as a counterbalance to excitatory connections and thus help to set the proper level of electrical activity within the brain. A deficiency in inhibitory signaling can lead to epilepsy, and Lin’s research also suggetal disorders, and may also contribute to improved educational methods that will benefit all children. Finally, underpinning our human neuroimaging work is a strong program of basic developmental neuroscience research, aimed at understanding the fundamental mechanisms by which the brain is shaped by experience during development and throughout life.

Developmental disorders are an important target for research at the McGovern Institute. Areas of research include: Autism, Dyslexia and Brain development and plasticity.

AUTISM

Nancy Kanwisher is leading a project to search for the neural basis of autism. Supported by the Ellison Medical Foundation, the aim of this project is to develop a battery of behavioral tests and standardized neuroimaging protocols designed to look at both the structure and the activity of the brain. These tests will then be applied to a large sample of children with and without autism in order to search for differences that distinguish the two groups.

One area of particular interest in the search for clues to autism is the temporal-parietal junction. This brain area was previously shown by Kanwisher and her former student Rebecca Saxe to be specifically activated by thinking about other people’s mental states – an ability that is impaired in people with autism.

John Gabrieli, in collaboration with the Boston Autism Consortium, is planning a large scale study of adolescents with autism spectrum disorder (ASD). The study will measure brain activation during a social cognition task in which subjects are asked to respond to emotional faces. Subjects will be scanned using multiple brain imaging methods, in order to identify brain differences that may underlie the difficulties in social interactions that are characteristic of autism.

DYSLEXIA

John Gabrieli has a longstanding interest in dyslexia, which he studies through a combination of behavioral testing and brain imaging methods, including magnetic resonance imaging (MRI) and electroencephalography. The goal of this work is twofold: (1) to develop methods for predicting as early as possible which children are at risk for reading difficulties and (2) to understand the brain mechanisms underlying dyslexia and its remediation, in order to develop more effective forms of treatment.

Nancy Kanwisher is studying the localization of different language functions within the brain. In one recent study, for example, she identified a brain area that sts that they may play a role in the development of autism.