Cognitive disorders such as autism and intellectual disability are often characterized by changes in the number, distribution, and shape of dendritic spines, the tiny bud-like protrusions where the majority of excitatory synapses are located. Harnett's previous work suggests that changes in spines are likely to have important functional consequences for neural information processing and hence for computations performed in the affected circuits. At MIT he plans to study this directly using mouse genetic models of human brain disorders. By investigating how anatomical abnormalities alter dendritic operations, he hopes to generate biophysical targets for experimental manipulation. The eventual goal is to causally link structural and functional changes at the cellular level with the aberrant computations that lead to pathological behaviors.