Erik Jonsson School of Engineering, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road GR41, Richardson TX 75080, USA.
Chem Senses. 2012 Jul;37(6):533-40. doi: 10.1093/chemse/bjs006. Epub 2012 Feb 21.
Rats were trained in a 2-alternative odor choice task to discriminate between a 10-component odor mixture and the same mixture with one component removed and replaced with 1 of 3 concentrations of a different monomolecular odor (contaminant). All stimuli were presented within a training session, thus the rat essentially had to learn to discriminate the 10-component mixture from "not" the 10-component mixture. Rats performed most poorly discriminating the complete mixture from the mixture with one component removed and no contaminant added. As the concentration of the contaminant increased from 10 ppm to a concentration equal to the other components (100 ppm), discrimination improved linearly. In analyses of individual differences, rats that spent more time in the sampling port (sampling and making a decision) were more accurate than rats that spent less time. Together, these results emphasize the balance between perceptual stability and perceptual discrimination expressed by the olfactory system dealing with dynamic mixtures and the robust effects of contamination on those processes. In addition, they provide further support that modification of sampling/decision time is a strategy used by rats to deal with difficult discriminations of complex odors.
老鼠在 2 种选择气味任务中接受训练，以区分 10 种成分的气味混合物和去除一种成分并用 3 种浓度的不同单分子气味（污染物）中的 1 种替代后的相同混合物。所有刺激都在一次训练会议中呈现，因此老鼠必须学会从“不是”10 种成分混合物中区分 10 种成分混合物。老鼠在区分完整混合物与去除一种成分且未添加污染物的混合物方面表现最差。随着污染物浓度从 10ppm 增加到与其他成分相同的浓度（100ppm），辨别能力线性提高。在个体差异分析中，在取样口花费更多时间（取样和做出决策）的老鼠比花费较少时间的老鼠更准确。这些结果共同强调了嗅觉系统在处理动态混合物时表现出的感知稳定性和感知辨别之间的平衡，以及污染对这些过程的强大影响。此外，它们进一步支持这样的观点，即改变取样/决策时间是老鼠用来处理复杂气味的困难辨别任务的一种策略。
