Do you have a good sense of smell and are also good at navigation? A series of studies by Canadian researchers found that they are linked - and that these abilities are located in overlapping brain areas - the orbitofrontal cortex and hippocampus. The Canadian researchers found that both the cortical thickness of the left orbitofrontal cortex and the right hippocampus were bigger in the better smellers and better navigators (the subjects had MRI scans).
The researchers say the findings support the view that olfaction (the sense of smell) evolved to aid navigation - this hypothesis is called the olfactory spatial hypothesis. For example, all animals use chemical cues to navigate, to find food, to avoid being preyed upon, while in contrast vision and hearing are not present in all animals. In humans, good navigators have what the researchers call "spatial memory". From Laura Sanders at Science News:
We may truly be led by our noses. A sense of smell and a sense of navigation are linked in our brains, scientists propose.
Neuroscientist Louisa Dahmani and colleagues asked 57 young people to navigate through a virtual town on a computer screen before being tested on how well they could get from one spot to another. The same young people’s smelling abilities were also scrutinized. After a sniff of one of 40 odor-infused felt-tip pens, participants were shown four words on a screen and asked to choose the one that matched the smell. On these two seemingly different tasks, the superior smellers and the superior navigators turned out to be one and the same, the team found.
Scientists linked both skills to certain spots in the brain: The left orbitofrontal cortex and the right hippocampus were both bigger in the better smellers and better navigators. While the orbitofrontal cortex has been tied to smelling, the hippocampus is known to be involved in both smelling and navigation. A separate group of 9 people who had damaged orbitofrontal cortices had more trouble with navigation and smell identification, the researchers report October 16 in Nature Communications.