We Induced Smells With Ultrasound
a day ago
- #ultrasound
- #neuroscience
- #olfaction
- Researchers successfully induced distinct scents like campfire burn and fresh air by stimulating the olfactory bulb with focused ultrasound.
- The olfactory bulb was targeted by placing an ultrasound probe on the forehead and angling it downward, overcoming challenges like air interference in the nasal cavity.
- A makeshift headset with a jello-like pad and even a taped knife was used to stabilize the ultrasound probe for consistent results.
- Key ultrasound parameters included a 300 kHz frequency, 39 mm focal depth, and 50–55° steering angles to effectively stimulate the olfactory bulb.
- Safety measures ensured the ultrasound intensity was within safe limits, and the optic nerve was avoided by maintaining specific angles.
- Four different scents were reliably induced in two participants, with sensations varying from strong, localized smells to diffuse impressions.
- The olfactory system's high dimensionality (400 receptor types) suggests potential for non-invasive neuromodulation, possibly encoding complex information like semantic meaning.
- The olfactory system's direct connection to memory (hippocampus) and emotion (amygdala) makes it a promising channel for brain-computer interfaces.
- Future steps include improving setup stability, increasing frequency, and exploring more focal locations to enhance the system's resolution and bit rate.