Andrew Alexander, Ph.D.

Postdoctoral Fellow, Boston University

Livestream via Zoom

Dr. Alexander  will present:    The association cortex spatial transformation network

Spatial transformation is a critical neural computation in which the locations of stimuli in the external world, experienced via disparate sensory processes, are registered across distinct coordinate systems. During navigation, information about the configuration of external features is initially acquired via sensory modalities in egocentric coordinates, but is then transformed into a map-like internal model of locations, landmarks, and goals relative to the external world (i.e. allocentric coordinate frame) that can subsequently be utilized to guide actions. Here, I present work investigating the role of association cortices in spatial transformations including during ethologically-inspired predation behavior. These experiments reveal computational building blocks for mediating transformations between egocentric and allocentric coordinate frames, including the discovery of a subpopulation of retrosplenial cortex neurons that map the position of external features in egocentric coordinates. I have also explored how these signals could be synchronized with hippocampal processing in a state-dependent manner via network oscillations. Future work will utilize projection-specific neuroimaging and optogenetics to characterize and perturb dynamics in these neural circuits in both navigation and memory tasks, including during performance of a novel target pursuit assay designed to test the flexibility of navigation computations.

Host: Dr. Patrick McGrath