小柯机器人

美国国家药物滥用研究所Thorsten Kahnt团队近期取得重要研究进展，他们研究利用高精度绘图揭示了人类大脑中气味编码的结构。相关研究成果2023年8月24日在线发表于《自然—神经科学》杂志上。

据介绍，气味感知本质上是主观的。先前的研究表明，气味分子会唤起嗅觉皮层的分布式活动模式，但这些模式如何映射到主观气味感知上仍不清楚。

研究人员收集了3名受试者对160种气味的神经成像反应(每个受试者18小时)，以探索特异气味感知的神经编码机制。研究人员发现，眶额皮层（OFC）的活动代表了气味在粗略定义的感知之上的细粒度感知特征，而梨状皮层（PirC）和杏仁核的这种差异则不那么明显。

此外，感知编码模型的实现使研究人员能够预测对新气味的嗅觉功能磁共振成像反应，揭示了编码感知空间的维度从PirC到OFC增加。低阶维的编码具有普遍性，而高阶维的编码具有特殊性。

总之，这些结果为气味编码的皮层机制提供了新的见解，并表明主观嗅觉感知存在于OFC中。

附：英文原文

Title: High-precision mapping reveals the structure of odor coding in the human brain

Author: Sagar, Vivek, Shanahan, Laura K., Zelano, Christina M., Gottfried, Jay A., Kahnt, Thorsten

Issue&Volume: 2023-08-24

Abstract: Odor perception is inherently subjective. Previous work has shown that odorous molecules evoke distributed activity patterns in olfactory cortices, but how these patterns map on to subjective odor percepts remains unclear. In the present study, we collected neuroimaging responses to 160 odors from 3 individual subjects (18h per subject) to probe the neural coding scheme underlying idiosyncratic odor perception. We found that activity in the orbitofrontal cortex (OFC) represents the fine-grained perceptual identity of odors over and above coarsely defined percepts, whereas this difference is less pronounced in the piriform cortex (PirC) and amygdala. Furthermore, the implementation of perceptual encoding models enabled us to predict olfactory functional magnetic resonance imaging responses to new odors, revealing that the dimensionality of the encoded perceptual spaces increases from the PirC to the OFC. Whereas encoding of lower-order dimensions generalizes across subjects, encoding of higher-order dimensions is idiosyncratic. These results provide new insights into cortical mechanisms of odor coding and suggest that subjective olfactory percepts reside in the OFC.

DOI: 10.1038/s41593-023-01414-4

Source: https://www.nature.com/articles/s41593-023-01414-4

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