Nov 2018 New Atlas
Cochlear implants allow deaf people to hear by electrically stimulating their auditory nerves, and have been doing so for years. While that's all very well and good, what about people who have lost their sense of smell? Well, new research suggests that we may be getting closer to an electrical implant for them, too.
The study involved stimulation of the olfactory bulb, depicted here as the bulb visible behind the eye
In a study conducted by scientists at the Harvard-affiliated Massachusetts Eye and Ear institute, five test subjects had electrodes endoscopically placed within their sinus cavity. Aged 43 to 72 years old, all of the people had an intact ability to smell, which was confirmed by a 40-item smell identification test.
Those electrodes were subsequently used to stimulate nerves connected to each individual's olfactory bulb, which is a part of the brain that processes and relays smell information from the nose. When this happened, three of the participants reported scents such as those of onions and antiseptic, along with sour and fruity aromas – the perception of these odors was artificially induced by the electrical stimulation.
Based on these results, the researchers now hope that implanted devices could someday detect various smell molecules entering the nose, and respond by stimulating the olfactory bulb accordingly. The technology would specifically be aimed at people who are unable to smell due to nerve damage, as other causes of anosmia (loss of the sense of smell) can often be treated by other means. "There's currently so little that we can do for these patients, and we hope to eventually be able to reestablish smell in people who don't have a sense of smell," says Dr. Eric Holbrook, corresponding author of a paper on the study. "Now we know that electrical impulses to the olfactory bulb can provide a sense of smell — and that's encouraging."