Cited research: Curr. Biol. doi:10.1016/j.cub.2010.05.059 (2010)

For humans and other primates, sight tends to dominate sense of smell; often what we see affects what we smell. Researchers have found evidence that the opposite may also be true: olfaction can influence visual perception.

Wen Zhou, at the Chinese Academy of Sciences in Beijing, and her colleagues showed volunteers two images, one of a rose and one of marker pens. The volunteers viewed the images through special glasses so that each eye saw a different image at the same time, although the volunteers were aware of only one image at a time. They were also exposed to odorants that smelled like either roses or pens.

The volunteers reported seeing the rose for longer periods of time when sensing the rose smell, and a similar bias when smelling the pens. The authors also show that the effect is partly subconscious. C.L.