Study shows correlation between spatial memory and smell

People with better spatial memory are also better at identifying odors, according to a study published this week in Nature Communications . The study builds on a recent theory that the main reason for the evolution of smell was to help navigation because most animals support mainly on smell to find food and avoid predators. The McGill research team, led by Véronique Bohbot of the McGill Department of Psychiatry and the Douglas Mental Health University Institute, hypothesized that if this were the case, there would be a problem. close connection between navigation and olfaction. The researchers were able to show, for the first time, that similar regions of the brain (the hippocampus and the medial orbitofrontal cortex) are involved in these seemingly very different activities. They also discovered that the medial orbitofrontal cortex (mOFC), known to be involved in olfaction, is also essential to spatial memory.

To test the correlation between spatial memory and the sense of smell, 57 participants (all male young women) were invited to perform various tasks related to spatial memory. In one of them, they had about 20 minutes to explore a virtual city, browsing every street and pbading important landmarks (schools, swimming pool and shops). They were then asked to find direct routes between some of the landmarks. Participants were then asked to identify 40 different smells, ranging from basil to strawberry to cinnamon.

Researchers used a structural MRI to examine various regions of the brain known for their badociation with olfaction and spatial memory. both in space navigation and in odor recognition, there was a tendency to have a larger right hippocampus (a region of the brain known to be involved in long-term memory) and a thicker left MFC.

Since the mofc, he was known to be critical for the olfaction. , had not yet been badociated with space navigation, the researchers then confirmed their findings through another experiment involving nine people with lesions in this area of ​​the brain. They found that patients with MOPO lesions had olfactory and spatial memory deficits, while patients with lesions elsewhere in the brain did not have these deficits.

"We were not sure, on entering, that Better People identify odor would also facilitate navigation," says Louisa Dahmani, who did the research during her PhD at McGill University. and who is currently doing a post-doctorate at Harvard. "The results were therefore a real surprise."

Véronique Bohbot, the main author, adds: "The fact that both functions seem to support similar brain regions supports the idea that brain systems evolve at the same time. same time – although this is the theory, rather than anything we wanted to show in this article. All we can say is that we now know a little more about the brain systems involved in both navigation and olfaction. "