The Geometry of Abstraction in Multiple Brain Areas in Multiple Species

Join us for a talk by Stefano Fusi, Professor of Neuroscience at MIT and Principal Investigator at Columbia’s Zuckerman Institute. This talk is part of the Kempner Seminar Series, a research-level seminar series on recent advances in the field.

Neurons in the mammalian brain often exhibit complex, non-linear responses to multiple task variables (mixed selectivity). Despite the diversity of these responses, which are seemingly disorganized, it is often possible to observe an interesting structure in the representational geometry: task-relevant variables are encoded in approximately orthogonal subspaces in the neural activity space. This encoding is a signature of low-dimensional disentangled representations, it is typically the result of a process of abstraction and allows linear readouts to readily generalize to novel situations. We show that these representations are observed in multiple brain areas in rodents and in human and non-human primates. The representational geometry can often predict the generalization behavior of the subjects.