Abstract
Neurons often encode highly heterogeneous non-linear functions of multiple task variables, a signature of a high-dimensional geometry. We studied the representational geometry in the somatosensory cortex of mice trained to report the curvature of objects touched by their whiskers. High-speed videos of the whiskers revealed that the task can be solved by linearly integrating multiple whisker contacts over time. However, the neural activity in somatosensory cortex reflects non-linear integration of spatio-temporal features of the sensory inputs. Although the responses at first appeared disorganized, we identified an interesting structure in the representational geometry: different whisker contacts are disentangled variables represented in approximately, but not fully, orthogonal subspaces of the neural activity space. This geometry allows linear readouts to perform a broad class of tasks of different complexities without compromising the ability to generalize to novel situations.
Nogueira, R., Rodgers, C. C., Bruno, R. M., & Fusi, S. (2023). The geometry of cortical representations of touch in rodents. Nat Neurosci, 1-12.[LINK]
Speaker: Fengjun Ma
Time: 9:00 am, 2023/03/29
Location: CIBR A6 Meeting Room
