Research
The development of social, cognitive, motor, and language abilities in children is remarkably heterogeneous. Children exhibit different developmental trajectories with some advancing very quickly and others achieving developmental milestones slowly and in unexpected order. When development is altered, such as in autism, different children can exhibit a wide variety of distinct combinations of behavioral symptoms and challenges in multiple domains. As the saying goes "if you know one child with autism, you know one child with autism". Heterogeneity is also apparent in the genetics and neurophysiology of autism, which are highly diverse such that there are currently no biological markers for the condition.
The large heterogeneity apparent across children with both typical and atypical development creates a huge challenge for research, because it makes it difficult to identify developmental conditions (such as autism) and even more difficult to quantify behaviors and symptoms in reliable ways. A key problem is that most of the existing tools for assessing behavior in children rely on observations made by either parents or clinicians. These tools are subjective and biased in different ways such that there is often little agreement across different tools and reporters (e.g., parent questionnaires and clinical assessments).
Hence, advancing research requires the development of direct, objective, and reliable techniques for measuring relevant behaviors, skills, and abilities in standardized ways. These techniques need to be applicable in longitudinal studies with large cohorts to establish population, age dependent norms.
With this in mind, we are developing new techniques to measure the development of social skills, language abilities, sensory function, and motor abilities as well as sleep. We test these techniques within the context of autism research where we compare behaviors and abilities across typically and atypically developing children in multiple age groups.
Specific research programs in the lab include:
Movement analysis
Many children with autism move differently. This research focuses on three types of movement analyses that utilize computer vision techniques to analyze video recordings from ADOS assessments:
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Social exploration - in this project we study how the child moves in the assessment room using measures such as the distance between child and clinician, the amount of approaches towards the clinician, the amount of time facing the clinician, and more (see relevant paper).
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Stereotypical movements - in this project we are training deep learning algorithms to identify video segments where children exhibit stereotypical movements, thereby enabling us to quantify their severity in individual children (see relevant paper).
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Facial expressions - social communication is heavily reliant on proper use of facial expressions, a social skill that develops early in life. In this project we are measuring movements of facial muscle groups (action units) and analyzing their kinematics to identify difficulties in the expression of emotions.
Diagnosis and developmental trajectories
Children with autism are diagnosed at different ages and develop differently over time. Some demonstrate remarkable improvements while others deteriorate. This research attempts to identify children with better outcome in specific behavioral domains (e.g., social skills or language) and determine why:
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Diagnosis - how do differences in the age of diagnosis and subsequent placement in intervention programs impact 1-2 year outcomes of children with specific symptoms (relevant paper).
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Educational settings - here we are comparing 1-2 year outcomes of children with autism who are placed in special education versus mainstream education settings (relevant paper).
Characterizing developmental heterogeneity
How is the development of different behaviors related in children with and without autism? In these studies we examine, for example, how sleep disturbances are associated with sensory sensitivities throughout early development (relevant paper), or how language regression is associated with early motor development (relevant paper).
Sleep studies
Approximately 50% of children with autism have insomnia (i.e., severe sleep disturbances). We are performing several types of studies to characterize sleep physiology and better understand these disturbances, their potential causes, and their impact on development of social, language, and motor abilities:
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Polysomnography - we are performing classical sleep lab studies and have demonstrated that some children with autism have reduced sleep pressure, which may explain their difficulty to fall asleep (relevant paper).
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Sensors - we are using actigraphy and consumer devices such as Fitbit to study sleep at home over extended periods of time.
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Impact - we are studying how sleep disturbances generate aberrant behaviors including irritability, tantrums, hyperactivity, and other symptoms (relevant paper).
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Behavioral intervention - we are testing the effectiveness of parent training in sleep hygiene and techniques to reduce the dependency of child sleep onset on parent presence.
Eye tracking
The development of social skills requires attention to social information from an early age. However, some children with autism observe the world differently. This is apparent, for example, in the tendency of some children to avoid eye contact with others. Over the last several years we have acquired >700 eye tracking sessions from children with and without autism as they observe different movies of social interactions. We are studying:
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How does social attention differ in children with autism? (relevant paper).
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Are early gaze preference differences in autism due to differences in basic oculomotor control? (relevant paper) or regulation of pupil diameter?
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Can we predict the social skills of an individual child from their eye gaze patterns?
Structural and functional MRI
We have a extensive track record in studying brain structure and function in autism using a variety of imaging techniques. Studies include:
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Assessment of differences in brain volume, cortical thickness, and cortical surface area across individuals with and without autism (relevant paper) as well as comparisons of early head circumference development (relevant paper).
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Assessment of mirror system fMRI responses in adults with autism as they observe and perform movements including an analysis of movement-selectivity (relevant paper).
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Demonstration that some adults with autism have unreliable brain responses to sensory stimuli across multiple modalities (relevant paper).
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Demonstration that inter-hemispheric functional connectivity (i.e., neural synchronization) is weaker in some children with autism (relevant paper). The same children also exhibit DTI differences in corpus callosum white matter fibers indicative of poor inter-hemispheric structural connectivity (relevant paper).
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In newer projects we are examining whether some children with autism have excessive extra-axial CSF also known as benign external hydrocephalus during early periods of development.
