瑞士苏黎世大学Fritjof Helmchen和Shuting Han研究团队近日取得一项新成果。经过不懈努力，他们研究出小鼠新皮层中与行为相关自上而下的跨模态预测。2024年1月4日，国际学术期刊《自然-神经科学》发表了这一成果。

为了解决大脑如何调控预测与感觉输出的矛盾，研究人员同时对小鼠躯体感觉桶状皮层和后顶叶皮层的神经元群，在听觉诱导纹理辨别任务中的表现进行了成像。在学习了固定音调-纹理匹配任务的小鼠中，不匹配配对的呈现会诱发基于音调的纹理预测与实际纹理输入之间的冲突。

当根据预测纹理而非实际纹理做出决定时，自上而下的信息流占主导地位；两个区域的纹理表征都发生改变时而自下而上的信息流占主导地位，会导致正确的表征和行为选择。该研究结果为小鼠新皮层的分层预测编码提供了证据。

据介绍，动物通过预测环境和行为后果来适应不断变化的世界。预测编码假说认为，大脑会产生预测，并不断将其与感觉输入进行比较，从而指导行为。然而，仍不清楚大脑如何协调自上而下的预测与自下而上感官信息之间的矛盾。

附：英文原文

Title: Behavior-relevant top-down cross-modal predictions in mouse neocortex

Author: Han, Shuting, Helmchen, Fritjof

Issue&Volume: 2024-01-04

Abstract: Animals adapt to a constantly changing world by predicting their environment and the consequences of their actions. The predictive coding hypothesis proposes that the brain generates predictions and continuously compares them with sensory inputs to guide behavior. However, how the brain reconciles conflicting top-down predictions and bottom-up sensory information remains unclear. To address this question, we simultaneously imaged neuronal populations in the mouse somatosensory barrel cortex and posterior parietal cortex during an auditory-cued texture discrimination task. In mice that had learned the task with fixed tone–texture matching, the presentation of mismatched pairing induced conflicts between tone-based texture predictions and actual texture inputs. When decisions were based on the predicted rather than the actual texture, top-down information flow was dominant and texture representations in both areas were modified, whereas dominant bottom-up information flow led to correct representations and behavioral choice. Our findings provide evidence for hierarchical predictive coding in the mouse neocortex.

DOI: 10.1038/s41593-023-01534-x

Source: https://www.nature.com/articles/s41593-023-01534-x