Cain W S, Stevens J C, Nickou C M, Giles A, Johnston I, Garcia-Medina M R
John B Pierce Laboratory, New Haven, CT 06519, USA.
Perception. 1995;24(12):1457-72. doi: 10.1068/p241457.
In the first of three studies, children (aged 8 to 14 years) were found to perform worse than young and middle-aged adults in unprompted identification of doors, with average performance much like that of elderly adults. Comparisons on other tasks, specifically odor threshold, prompted odor identification, and object naming (Boston Naming Test), across the life span (five groups) revealed that children have the same excellent olfactory sensitivity as young adults and merely lack odor-specific knowledge that accumulates slowly through life. Such knowledge apparently accumulates so slowly that age-associated discriminative losses, measurable by early middle age, begin to wear away gains obtained through experience before odors can become overlearned. In the second study, a novel adaptive psychophysical method, the step procedure, confirmed the equivalent sensitivity of children and young adults. In the third study, a paired-associate task illustrated the sluggish course of odor learning. Young adults outperformed children, though the youngest group, first graders, made up ground relatively fast. For children and adults, common odors facilitated performance relative to novel odors. The outcome highlighted the relevance of semantic factors in odor learning irrespective of age.
在三项研究的第一项中，研究人员发现，8至14岁的儿童在未得到提示的情况下识别门的表现比年轻人和中年成年人差，其平均表现与老年人很相似。对整个寿命周期（五组）在其他任务上的比较，特别是气味阈值、提示气味识别和物体命名（波士顿命名测试），结果显示儿童与年轻人具有相同出色的嗅觉敏感度，只是缺乏随着年龄增长而缓慢积累的特定气味知识。这种知识积累得非常缓慢，以至于到中年早期可测量的与年龄相关的辨别能力下降开始抵消在气味被过度学习之前通过经验获得的优势。在第二项研究中，一种新颖的自适应心理物理学方法——阶梯程序，证实了儿童和年轻人的嗅觉敏感度相当。在第三项研究中，一项配对联想任务说明了气味学习的缓慢过程。年轻人的表现优于儿童，不过最年幼的一年级学生组弥补差距的速度相对较快。对于儿童和成年人来说，常见气味相对于新气味更有助于表现。该结果突出了语义因素在气味学习中的相关性，而与年龄无关。
