CTN: Mitra Javadzadeh

Title: Inter-area connectivity and the emergence of multi-timescale cortical dynamics

Abstract: The brain generates behaviors spanning a wide range of timescales, from rapid sensory responses to the slow integrative processes underlying cognition. How does the anatomical connectivity of the neocortex give rise to such flexible, multi-timescale dynamics? In this talk, I will examine how the parcellation of the neocortex into specialized areas, coupled through reciprocal connections, structures its dynamical landscape.

In Part I, I will present experimental and modeling work combining simultaneous multi-area recordings in mouse visual cortex with focal optogenetic perturbations and biologically constrained latent circuit models. We show that reciprocal excitatory connections between primary (V1) and higher visual cortex (LM) generate an approximate line attractor in their joint dynamics. These dynamics selectively slow the decay of activity patterns that encode stimulus features consistently across areas, promoting the gradual emergence of cross-area consensus.

In Part II, I extend these findings within an analytical framework for balanced multi-area networks. We show how the structure and asymmetry of feedforward and feedback connectivity between cortical areas tune their contribution to globally consistent activity patterns. This framework makes model-free predictions on the organization of timescales across the neocortex. Furthermore, we validate these predictions with new experiments using switchable optoGPCRs to selectively disrupt long-range cortical communication.

Together, these results link anatomical connectivity to collective cortical computation, providing a theory for how distributed brain areas reconcile information through structured multi-area dynamics.