我們每天睡覺都會做各種各樣的夢。在描述它們的時候，我們常說“當時我腦海里浮現出……”這樣的話。實際上，決定你做什么夢的可能并不是你的大腦，而是你鼻子的“工作”。

What you smell may influence emotions in your dreams, according to a new study.

When researchers gave dreaming subjects whiffs of rose scent, the subjects reported rosier dreams. The scent of rotten eggs（腐敗的雞蛋）, on the other hand, provoked unpleasant dreams, the study found.

The sense of smell is known to be closely associated with the brain's limbic system（大腦邊緣系統）, which governs emotion and behavior.

"If odor has a strong effect on your emotions when you're awake, it makes sense for it to have a strong effect on your emotions when you're asleep," said Stuck, who presented the research Sunday in Chicago at the annual meeting of the American Academy of Otolaryngology（耳鼻喉學）—Head and Neck Surgery. The findings have not been published.

Stuck and his colleagues studied the effects of rose and rotten-egg odors on 15 healthy women in their 20s. Young women have been shown to have the best sense of smell, they said.

Tubes were taped to the subjects' nostrils, linking them to olfactometers（嗅覺測量儀）. The devices pumped constant streams of air into their noses so a gust of odor would not wake them.

The subjects' brain activity was also being monitored. When they reached the rapid-eye-movement (REM) stage of sleep, when most dreams occur, a shot of scent was administered via the olfactometer for ten seconds.

The dreamers continued sleeping for another minute until the scientists woke them up and asked them to describe their dreams and rate the experience as emotionally negative or positive.

The results showed that smelling roses gave nearly all dreams a pleasant tint, whereas the rotten eggs colored dreams negatively.