Research Overview

Neurophysiology of Autism Spectrum Disorders

The Desimone lab works in collaboration with Guoping Feng lab at the McGovern Institute for Brain Research, studying the neural mechanism underlying autism disorder (specifically the Phelan-McDermid Syndrome). Autism Spectrum Disorder (ASD), is a neurodevelopmental disorder that affects a person’s ability to communicate, socialize, and engage in repetitive behaviors. The disorder is characterized by a wide range of symptoms, which can vary in severity and may include difficulties with speech and language, social interaction, sensory processing, and motor coordination.

Autism is estimated to affect about 1 in 36 children in the United States. However, there is currently no mechanistic drugs or treatments available, due to limited understanding of the disorder. Our goal is to characterize the brain circuit level differences that explain the behavioral abnormalities and neurophysiology in ASD subjects in tasks related to perception, cognitive, and social behaviors. Understanding these mechanisms will aid in the development of treatments in the near future.

Managing Information Overload

Just as our world buzzes with distractions, the neurons in our brain are constantly bombarded with messages. Some messages contain relevant information, but many do not.

By studying the visual system of humans and animals, our lab has shown that relevant information is selectively amplified in certain brain regions, while irrelevant information is suppressed. One reason this happens is that neurons whose activity reflects the relevant information become synchronized with one another. The rhythmic activity produced by a group of synchronized neurons resembles a chorus chanting a tune that rises above the background chatter of the crowd. This synchronized chanting allows the relevant information to be “heard” more efficiently by other brain regions.

Our work also suggests that the prefrontal cortex — a brain region known to be involved in planning and executive control of behavior — most likely serves as the conductor of this neural chorus. The prefrontal cortex provides a top-down signal that coordinates rhythmic activity across multiple brain regions. We believe this pattern of rhythmic activity is not just specific to attention, but could also represent a more general mechanism for communication between different parts of the brain.

Staying on Message

Sometimes, distraction can be a good thing – a train barreling towards us should grab our attention regardless of what else we’re doing. But these kinds of “bottom-up” distractions must be balanced against the need to stay on message. If this balance is disrupted, many aspects of life may be impaired as a result. We believe that altered neural synchrony may underlie many brain disorders that disrupt attention – such as attention deficit disorder, Parkinson’s disease, and schizophrenia – and that searching for ways to enhance synchrony may be a useful strategy for developing new treatments for these conditions.