美国哥伦比亚大学Stefano Fusi和Ramon Nogueira团队合作发现啮齿类动物触觉皮层表征的几何形状。相关论文发表在2023年1月9日出版的《自然—神经科学》杂志上。
他们研究了老鼠体感皮层的表征几何，这些老鼠被训练来报告被它们的胡须接触的物体的曲率。胡须的高速视频显示，该任务可以通过随着时间的推移对多个胡须接触进行线性积分来解决。体感觉皮层的神经活动反映了感觉输入的时空特征的非线性整合。虽然最初的反应看起来是杂乱无章的，但他们在表征几何中发现了一个有趣的结构:不同的胡须接触是在神经活动空间的近似(但不是完全)正交子空间中表示的解纠缠变量。这种几何结构允许线性读出执行各种不同复杂性的任务，而不影响归纳到新情况的能力。
据介绍，神经元通常对多个任务变量的高度异构的非线性函数进行编码，这是高维几何的一个特征。
附：英文原文
Title: The geometry of cortical representations of touch in rodents
Author: Nogueira, Ramon, Rodgers, Chris C., Bruno, Randy M., Fusi, Stefano
Issue&Volume: 2023-01-09
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.
DOI: 10.1038/s41593-022-01237-9
Source: https://www.nature.com/articles/s41593-022-01237-9
Nature Neuroscience：《自然—神经科学》，创刊于1998年。隶属于施普林格·自然出版集团，最新IF：28.771
官方网址：https://www.nature.com/neuro/
投稿链接：https://mts-nn.nature.com/cgi-bin/main.plex
本期文章：《自然—神经科学》：Online/在线发表
