美国哥伦比亚大学W. Jeffrey Johnston等研究人员发现，价值的半正交亚空间介导绑定和泛化的权衡。该项研究成果于2024年9月17日在线发表在《自然—神经科学》杂志上。

研究人员表示，在选择选项时，人们必须将它们的价值与选择它们所需的动作联系起来。研究人员假设大脑通过神经群体亚空间解决这一绑定问题。

研究人员探究了进行选择任务的猕猴，并发现五个对奖励敏感的区域内的神经群体，以不同的亚空间编码左侧和右侧呈现的提议价值。这种编码足以将提议的价值与其位置绑定，同时保留抽象的价值信息。在提议呈现之后，所有区域在正交亚空间内分别编码第一和第二个提议的价值；这种正交化也实现了绑定。

研究人员的通过亚空间绑定的假设提出了两个新预测，并且数据证实了这些预测。首先，行为错误应与空间神经错误绑定相关，而非时间错误绑定。其次，即使控制了价值差异，当提议的价值较低或较高时，行为错误应比中等价值时更多。综合这些结果，支持了大脑使用半正交亚空间进行特征绑定的观点。

附：英文原文

Title: Semi-orthogonal subspaces for value mediate a binding and generalization trade-off

Author: Johnston, W. Jeffrey, Fine, Justin M., Yoo, Seng Bum Michael, Ebitz, R. Becket, Hayden, Benjamin Y.

Issue&Volume: 2024-09-17

Abstract: When choosing between options, we must associate their values with the actions needed to select them. We hypothesize that the brain solves this binding problem through neural population subspaces. Here, in macaques performing a choice task, we show that neural populations in five reward-sensitive regions encode the values of offers presented on the left and right in distinct subspaces. This encoding is sufficient to bind offer values to their locations while preserving abstract value information. After offer presentation, all areas encode the value of the first and second offers in orthogonal subspaces; this orthogonalization also affords binding. Our binding-by-subspace hypothesis makes two new predictions confirmed by the data. First, behavioral errors should correlate with spatial, but not temporal, neural misbinding. Second, behavioral errors should increase when offers have low or high values, compared to medium values, even when controlling for value difference. Together, these results support the idea that the brain uses semi-orthogonal subspaces to bind features.

DOI: 10.1038/s41593-024-01758-5

Source: https://www.nature.com/articles/s41593-024-01758-5