NB/CNS Seminar - Speaker: Ila Fiete | Tuesday, January 23, 2024 at 12 pm

Date: Tuesday, January 23, 2024

Reception: 11:30 am

Time: 12 pm

Location: Broad 100

Speaker: Ila Fiete

Professor

Department of Brain and Cognitive Sciences

McGovern Institute for Brain Research

MIT

Faculty Host: TBD

Title: Modeling the emergence of complex cortical structure from simple precursors in the brain: maps, hierarchies, and modules

Abstract: Modular and hierarchical structures are ubiquitous in the brain. Two distinct hypotheses for such morphogenesis involve genetic specification (the positional information hypothesis) or spontaneous structure emergence from symmetry breaking (the pattern formation hypothesis). Indeed, there is rich evidence supporting both hypotheses in different systems, and more recently evidence that both systems might interact, for instance with genetic specification providing an initial but relatively low-information scaffold of positional guidance and pattern formation constructing sharper structures by bootstrapping from this guidance. In this talk, I will consider the emergence of two systems in the brain: the visual processing hierarchy with topographic structure, and a modular cognitive circuit consisting of functionally independent grid cell networks that compute spatial location from velocity cues as animals move and navigate the world. I will describe how simple activity-driven growth and competition rules can lead to the emergence of topographically ordered sensory processing hierarchies, and how genetically specified smooth gradients with purely local recurrent interactions on two scales can lead to global module emergence. In sum, simple growth rules, local interactions and smooth gradients can interact to produce rich emergent order on multiple scales in the form of maps, modules, and hierarchies