以色列科学家研究发现，无论对孩子还是成人来说，有气味的物体会在他们的大脑中留下鲜明的印记，这就是为什么气味往往能勾起回忆的原因。
以色列魏茨曼科学研究所的雅拉·耶舒伦等人在新一期美国《当代生物学》杂志上发表论文说，无论香味还是臭味，大脑都能“铭刻”最初的记忆，但这种记忆仅限于气味。
为测试与气味有关的记忆，科学家向一组自愿接受测试的人展示了一些物品，这些物品或能发出气味，或能发出声音，其中有些物品的气味或声音是令人愉悦的，如梨和吉他，还有一些是令人反感的，如死鱼和动力钻。
科学家利用磁共振成像技术对被测试者的大脑进行扫描，他们发现，当被测试者遇到可发出气味的物体时，大脑海马区和扁桃核都会产生明显反应。但遇到可发出声音的物体时，就没有出现这种现象。一周后再要求他们回忆所遇到的物体，被测试者大多能回忆起有气味的物体，而不是可发出声音的物体。
大脑海马区对人的学习、记忆能力等有重要作用，而扁桃核是大脑控制情绪的中心。这两个部位有反应，表明大脑对与气味有关的物体更敏感。
科学家称，此项研究成果有可能帮助人们找到改善记忆力甚至治疗早期脑部创伤的新途径。（生物谷Bioon.com）
生物谷推荐原始出处：
Current Biology, 09 November 2009 doi:10.1016/j.cub.2009.09.066
The Privileged Brain Representation of First Olfactory Associations
Yaara Yeshurun1, , , Hadas Lapid1, Yadin Dudai1 and Noam Sobel1
1 Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
Authors [1], poets [2], and scientists [3,4,5,6] have been fascinated by the strength of childhood olfactory memories. Indeed, in long-term memory, the first odor-to-object association was stronger than subsequent associations of the same odor with other objects [7]. Here we tested the hypothesis that first odor associations enjoy a privileged brain representation. Because emotion impacts memory [8,9,10], we further asked whether the pleasantness of an odor would influence such a representation. On day 1, we associated the same visual objects initially with one, and subsequently with a second, set of pleasant and unpleasant olfactory and auditory stimuli. One week later, we presented the same visual objects and tested odor-associative memory concurrent with functional magnetic resonance brain imaging. We found that the power (% remembered) of early associations was enhanced when they were unpleasant, regardless of whether they were olfactory or auditory. Brain imaging, however, revealed a unique hippocampal activation for early olfactory but not auditory associations, regardless of whether they were pleasant or unpleasant. Activity within the hippocampus on day 1 predicted the olfactory but not auditory associations that would be remembered one week later. These findings confirmed the hypothesis of a privileged brain representation for first olfactory associations.
