Smell wired to spatial information
2 Jul 2015 by Evoluted New Media
Scientists have discovered that humans can map a location by using only their sense of smell.
A research team at the University of California in Berkley designed a smell-only experiment and found that the part of brain involved in the sense of smell – the olfactory bulb – can convert smells into spatial information.
“What we’ve found is that we humans have the capability to orient ourselves along highways of odours and crisscross landscapes using only our sense of smell,” said research leader Professor Lucia Jacobs.
The process of smelling is triggered by odour molecules that are identified by nasal receptors that send signals to the olfactory bulb to process the information. The team believe that the connection between smell, memory and navigation is that the olfactory bulb has a strong neural link to the hippocampus, a brain region which has an important role in information consolidation.
“Olfaction is like this background fabric to our world that we might not be conscious of, but we are using it to stay oriented,” Jacobs said. “We may not see a eucalyptus grove as we pass it at night, but our brain is encoding the smells and creating a map.”
In the study, published in PLOS ONE, the team measured the orientation ability of 45 participants in different sensory conditions in which their hearing, sight or smell was blocked. The test location involved a room with grids where containers with sponges were placed at points around the edge of the room. Two of the sponges were infused with essential oils; the aim of the participants was to locate these two fragrances.
The results showed that the participants navigated relatively closely to the targeted location when using only their sense of smell, compared to when other sensory inputs were blocked. The team discovered that the participants were not only following one scent but were also using information from both scents to orient themselves toward a point on an odour grid.
“We never thought humans could have a good enough sense of smell for this. The results are as obvious as the nose on my face,” said Professor Jacobs.
