Frasnelli Johannes, Charbonneau Genevieve, Collignon Olivier, Lepore Franco
Centre hospitalier universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada.
Chem Senses. 2009 Feb;34(2):139-44. doi: 10.1093/chemse/bjn068. Epub 2008 Nov 11.
For humans, the localization of an odorant seems only possible if the odorant also stimulates the trigeminal nerve. There is, however, some evidence that active sniffing may affect this ability and facilitate the localization of pure odorants. Therefore, we tested the ability of 40 subjects to localize a pure odorant and a mixed olfactory/trigeminal stimulus under 2 stimulation conditions: either odors were blown into the subjects' nostrils (passive) or subjects had to actively sniff the odors (active). Subjects could only reliably localize the mixed olfactory/trigeminal stimulus. However, we found a significant interaction between stimulation condition and nature of the odorant. So, the mixed olfactory/trigeminal stimulus was more localizable in the passive condition, whereas the pure odorant was better localized in the active condition. Interestingly, subjects had more correct answers after stimulation of the right nostril than of the left nostril (where subjects performed significantly below chance when stimulated with the pure odorant), suggesting possible laterality effects. These results suggest that active sniffing may affect our ability to localize odors. Other than mixed olfactory trigeminal stimuli, pure odorants are, however, not localizable even in active condition of sniffing.
对于人类而言，只有当气味剂也刺激三叉神经时，才有可能对其进行定位。然而，有一些证据表明，主动嗅吸可能会影响这种能力，并有助于对纯气味剂进行定位。因此，我们测试了40名受试者在两种刺激条件下对纯气味剂和混合嗅觉/三叉神经刺激物进行定位的能力：一种是将气味吹入受试者鼻孔（被动），另一种是受试者必须主动嗅吸气味（主动）。受试者只能可靠地定位混合嗅觉/三叉神经刺激物。然而，我们发现刺激条件与气味剂性质之间存在显著的交互作用。所以，混合嗅觉/三叉神经刺激物在被动条件下更易于定位，而纯气味剂在主动条件下定位效果更好。有趣的是，右侧鼻孔受到刺激后受试者的正确答案比左侧鼻孔更多（当用纯气味剂刺激左侧鼻孔时，受试者的表现明显低于随机水平），这表明可能存在单侧效应。这些结果表明，主动嗅吸可能会影响我们对气味进行定位的能力。然而，除了混合嗅觉三叉神经刺激物外，即使在主动嗅吸条件下，纯气味剂也无法定位。
