People may be literally led by their noses

A new study suggests senses of smell and navigation are linked in the brain

The brain tangles up senses of smell and direction, a new study suggests.

E. Otwell

Our sense of smell and sense of navigation are linked in our brains, a new study suggests. If true, we may truly be led by our noses.

Louisa Dahmani is a neuroscientist — someone who studies the brain. She works for Harvard University in Cambridge, Mass. Her team asked 57 young people to navigate through a virtual town on a computer screen. Afterward, each person was tested on how to get from one spot to another.

The researchers also tested each person’s smelling abilities. Participants sniffed one of 40 fragrant felt-tip pens. Then they had to match that smell to one of four words shown on a screen. These two tasks might have seemed unrelated. But the team found that the best smellers were also the best navigators.

Scientists linked both skills to certain spots in the brain. The left orbitofrontal (OR-bit-oh-FRUNT-ul) cortex and the right hippocampus (Hip-oh-KAMP-us) were both bigger in the better smellers and better navigators. The orbitofrontal cortex has been tied to smelling. The hippocampus is known to be involved in both our sense of smell and in navigation.

The researchers separately studied nine people who had damaged orbitofrontal cortices (KOR-tih-sees). Those people had more trouble with navigation and with identifying smells, the team found. The researchers shared their findings October 16 in Nature Communications. Dahmani did the work while at McGill University. That’s in Montreal, Canada.

A sense of smell may have evolved to help people find their way around. This idea is called the olfactory (Oal-FAK-tor-ee) spatial hypothesis. More specific aspects of smell, such as how good people are at detecting faint whiffs, might also be tied to navigation, the researchers suggest.

Laura Sanders is the neuroscience writer. She holds a Ph.D. in molecular biology from the University of Southern California.

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