We pointed an ultrasound probe at the scent-processing region of the brain to obtain different sensations. Different focal spots corresponded to different smells, which we’ve replicated first-try on two people and validated with a blind trial. The sensations we obtained are:
The sensation of fresh air, with a lot of oxygen The smell of garbage, like few-day-old fruit peels An ozone-like sensation, like you're next to an air ionizer A campfire smell of burning wood
Here is a video from our blind tasting:
Your browser does not support the video tag.
The Setup
Smells are processed in the olfactory bulb. We decided to try to stimulate it with focused ultrasound through the skull. As far as we know, no one seems to have done this kind of olfactory stimulation before - even in animals.
However, after being able to induce sensations of motion the previous week, it seemed promising to try the same for olfactory.
The Anatomy
The olfactory bulb, our target, is tucked behind the top of the nose. That turns out to be a pretty inconvenient location for a couple of reasons:
The nose doesn’t provide a flat surface for mounting a transducer for stimulation. It's mostly filled with air, which interferes with ultrasound. Ultrasound needs a continuous medium to travel through, and filling the nose with gel seemed rather unappealing.
... continue reading