Livermore A, Laing D G
School of Social Sciences & Liberal Studies, Charles Sturt University - Mitchell, Bathurst NSW, Australia.
Physiol Behav. 1998 Nov 15;65(2):311-20. doi: 10.1016/s0031-9384(98)00168-1.
Using a limited set of odorants, previous studies have indicated that the ability of humans to discriminate and identify the components of olfactory mixtures is limited to approximately four. However, the ability to generalize these results may have been limited by specific neural or cognitive interactions among the particular odorants used. In the present experiment, 41 subjects examined the influence of odor type (different individual odorants), from two very different odor sets, on the perception of the components of complex mixtures. One set contained odors that were selected by an expert panel to blend well in mixtures (good blenders), whereas the other contained odors that blended poorly in mixtures (poor blenders). The stimuli were common, dissimilar odorants of equivalent, moderate intensity, each of which was a single chemical. A computer-controlled air dilution olfactometer delivered a single odorant or a mixture containing up to eight odorants. Although the poor blenders were more easily discriminated, this superiority was displayed within a narrow range, and the ability of subjects to identify mixture components with either odor set was limited to approximately four. The results indicate that, whereas odor type can alter which odorants will be perceived in a mixture, the limited capacity to discriminate mixture components is independent of the type of odorants. These findings are discussed in terms of their implications for olfactory coding.
以往的研究使用了一组有限的气味剂，结果表明人类辨别和识别嗅觉混合物成分的能力大约局限于四种。然而，将这些结果进行推广的能力可能受到了所用特定气味剂之间特定神经或认知相互作用的限制。在本实验中，41名受试者研究了来自两组截然不同的气味剂中气味类型（不同的单一气味剂）对复杂混合物成分感知的影响。一组包含由专家小组挑选出的在混合物中能很好混合的气味剂（良好混合剂），而另一组包含在混合物中混合效果不佳的气味剂（不良混合剂）。刺激物是常见的、不同的、强度适中且等效的单一化学气味剂。一台计算机控制的空气稀释嗅觉计可输送单一气味剂或包含多达八种气味剂的混合物。尽管不良混合剂更容易被辨别，但这种优势仅在狭窄范围内表现出来，并且受试者识别任何一组气味剂混合物成分的能力都局限于大约四种。结果表明，虽然气味类型可以改变混合物中会被感知到的气味剂，但辨别混合物成分的有限能力与气味剂的类型无关。本文从这些发现对嗅觉编码的意义方面进行了讨论。
