Two New Grants Expand Pilot Awardee’s Research Into How We Process and Perceive Sound

By: Joslyn Cassano | Published: November 17, 2022

Andrew Dykstra, Ph.D.

Adults who can hear perfectly in an audiologist’s exam room may still find it hard to distinguish sounds against a noisy backdrop, especially as they age, says Andrew Dykstra, Ph.D., Assistant Professor of Biomedical Engineering at the University of Miami.

The relationship between aging and hearing ability has been central to Dr. Dykstra’s research since he earned a Pilot Award in 2020 from the Miami CTSI. “I’m interested in how we process and perceive sound across the lifespan and what goes wrong as people enter middle age and older years,” he said.

With new funding from a National Institutes of Health R21 grant, Dr. Dykstra and his team are looking at the balance between inhibitory neurotransmitters and excitatory neurotransmitters in the brain and their role in hearing.

New knowledge emerging from the R21 grant could eventually lead to the development of smarter hearing aids and new pharmaceutical treatments, says Dr. Dykstra. Hearing aids, though helpful in quiet settings, currently amplify all sounds for the listener. A better hearing aid would have the ability to recognize and amplify the sounds person wants to hear, while leaving background noise alone or even suppressing them.

“If we find there are reduced levels of inhibitory neurotransmitters in the central auditory cortex as people age, and we can identify them specifically,” he says.

One of the greatest gifts of the CTSI is the ability to help introduce me to my collaborators and to stay abreast of work being done by others, says Dykstra. “I try to pay attention broadly enough to the science that’s out there and to identify developments that could help with my own research,” he said.

This interest in potential synergies led Dr. Dykstra to a project with James Bonaiuto, Ph.D., a research scientist at CNRS Institut des Sciences Cognitives in Lyon, France, and head of the Decision, Action, and Neural Computation (DANC) lab.

Together, Dr. Dykstra and Dr. Bonaiuto secured a seed grant from the Fondation Pour l’Audition (FPA) to explore the neurophysiological underpinnings of auditory perception on the micro level using magnetoencephalography (MEG).

“My recent work has involved trying to push the boundaries of what is possible with MEG, mainly trying to use it to distinguish activity in different layers of the cortex,” said Dr. Bonaiuto. “From his modeling work, Dr. Dykstra has an extremely interesting hypothesis concerning how activity in different cortical layers underlies sound perception. We’re combining our expertise to test these hypotheses non-invasively in humans, in a way that was traditionally possible only with animal models.”

Dr. Dykstra hopes knowledge gained from the FPA grant will lead to better understanding of the underlying brain circuits involved in human hearing.

Recently, Dr. Dykstra was selected as a “Scialog” Fellow for a new three-year program called Molecular Basis of Cognition sponsored by the Research Corporation for Science Advancement (RSCA). RSCA brings together scientists who all share an interest in the molecular bass of cognition to inspire new thinking, and dissolve traditional cross-disciplinary barriers to collaboration. The first of three annual meetings of this program was held in Tuscon, Ariz., in October. The Fellowship enables Dr. Dykstra to apply for further seed funding from the sponsoring agencies.

“The first meeting was incredibly stimulating, and I’m hoping it will help me form new collaborations and establish new lines of research in auditory cognition.”