Molecules—the elementary units of substances—are commonly considered the units of processing in olfactory perception, giving rise to undifferentiated odour objects invariant to environmental variations. By selectively perturbing the processing of chemical substructures with adaptation (‘the psychologist’s microelectrode’) in a series of psychophysical and neuroimaging experiments (458 participants), we show that two perceptually distinct odorants sharing part of their structural features become significantly less discernible following adaptation to a third odorant containing their non-shared structural features, in manners independent of olfactory intensity, valence, quality or general olfactory adaptation. The effect is accompanied by reorganizations of ensemble activity patterns in the posterior piriform cortex that parallel subjective odour quality changes, in addition to substructure-based neural adaptations in the anterior piriform cortex and amygdala. Central representations of odour quality and the perceptual outcome thus embed submolecular structural information and are malleable by recent olfactory encounters.

分子——物质的基本单位——通常被认为是嗅觉感知中的处理单位，产生不受环境变化影响的未分化气味对象。通过在一系列心理物理和神经影像实验（458 名参与者）中选择性地扰乱具有适应性的化学子结构的处理（“心理学家的微电极”），我们表明，两种感知上不同的气味剂共享其部分结构特征，在适应后变得明显难以辨别。第三气味剂包含其非共享的结构特征，其方式独立于嗅觉强度、化合价、质量或一般嗅觉适应。除了前梨状皮层和杏仁核中基于亚结构的神经适应之外，这种效应还伴随着梨状后皮层中与主观气味质量变化平行的整体活动模式的重组。因此，气味质量和感知结果的中心表征嵌入了亚分子结构信息，并且可以通过最近的嗅觉体验进行调整。