PHYSICS PHD DISSERTATION DEFENSE: Byungwoo Kang
Ph.D. Candidate: Byungwoo Kang
Research Advisor: Shaul Druckmann
Date: Tuesday, September 28, 2021
Time: 3pm PDT
Title: Modularity and robustness of frontal cortical networks
Neural activity underlying short-term memory is maintained by interconnected networks of brain regions. It remains unknown how brain regions interact to maintain persistent activity while exhibiting robustness to corrupt information in parts of the network. We simultaneously measured activity in large neuronal populations across mouse frontal hemispheres to probe interactions between brain regions during short-term memory. Activity across hemispheres was highly coordinated to maintain coherent short-term memory. Across a population of mice, we uncovered individual variability in the organization of frontal cortical networks that explained the robustness of short-term memory. Modular organization across hemispheres prevented local perturbations from spreading and predicted the robustness of behavior. A dynamic gating mechanism organized frontal networks into modules that coordinate coherent information while gating out corrupt information. Our results show that robust short-term memory is mediated by redundant modular representations across brain regions. Modular organization naturally emerges in neural network models that learned robust dynamics.