Research Themes
I am a developmental cognitive neuroscientist who studies how sleep regulates brain function and structure during childhood and adolescence with a focus on neurodevelopment disorders such as attention-deficit-activity-hyperactivity-disorder (ADHD).
My work combines structural and functional neuroimaging, laboratory-based sleep EEG, and actigraphic field studies with complex cognitive performance testing and clinical assessments of child neurodevelopment and psychopathology.
SLEEP AND NEURODEVELOPMENT
My most recent work has applied sleep cognitive neuroscience to both typical and atypical cognitive development throughout adolescence. We've taken a specific focus on ADHD during early adolescence (e.g., 10-13 years) as these children experience routine struggles with their sleep while their daytime impairments mirror those of sleep deprivation. In a first paper, we documented a specific deficit in sleep spindle frequency EEG activity in ADHD moderating changes in overnight memory consolidation. In ongoing work funded by NIMH (K01MH109854) and the Rhode Island Foundation, we are combining all of our available methodologies to better understand how dysregulated sleep behavior (i.e., rhythms and regularity) and sleep physiology (i.e., EEG-indexed sleep homeostasis) accounts associations between brain structure and function and ADHD symptomatology during this critical age of life. We hope to identify novel mechanisms and windows of intervention by which we can one day aid youngsters suffering from neurodevelopmental disorders such as ADHD through improving and nuturing their sleep.
STRUCTURAL DETERMINANTS OF SLEEP
Sleep physiology as expressed in the EEG is determined by underlying brain structural anatomy. Our work has utilized the intimate link between structure and function to explore determinants of inter-individual variability in sleep, and sleep-supported brain function. We have identified that hippocampus grey matter is a powerful predictor of sleep spindle frequency and recovery slow wave activity. The latter structural association determine the vulnerability of an indidivudal's learning to sleep loss and the degree of learning restoration that occurs after recovery sleep. We've now turned towards child and adolescent brain development as a window of vulnerability for brain structure and sleep-dependent brain function alike.
SLEEP AND MEMORY
These studies focus on how the oscillations of NREM sleep regulate declarative memory processes within the hippocampus. This work has identified that sleep spindles support selective memory consolidation across sleep and NREM sleep slow wave activity during recovery sleep following sleep deprivation indexes the restoration of hippocampus-dependent memory. Ongoing work is extending these studies down into adolescence, while also examining the competing sleep and circadian determinants of hippocampus-dependent memory. By taking advantage of complex forced-desynchrony protocols in human subjects we can elegantly disentangle these two juxtaposed processes and how they contribute to sleep-dependent memory effects.
