A portable experimental apparatus for human olfactory fMRI experiments

Area of Science:

• Neuroscience
• Sensory Science
• Biomedical Engineering

Background:

• Human olfactory perception is typically measured using psychophysical methods or complex olfactometers.
• Existing olfactometry systems can be expensive, bulky, and not easily integrated with neuroimaging techniques like fMRI.

Purpose of the Study:

• To present a novel, inexpensive, and portable olfactometer designed for human functional Magnetic Resonance Imaging (fMRI) experiments.
• To develop a system that synchronizes odorant stimulus delivery with human nasal respiration and records behavioral responses concurrently.

Main Methods:

• The developed portable olfactometer was validated using psychophysical measures and photo-ionization detection.
• The system's ability to elicit neural activation was confirmed through brain imaging (fMRI).
• Odorant stimulus presentation was adjusted to match individual nasal respiration patterns.

Main Results:

• Psychophysical and photo-ionization detection validated a linear relationship between odorant concentration, perceived intensity, and vapor concentration.
• Brain imaging confirmed neural activation in established olfactory processing areas.
• The system demonstrated effective synchronization of odor delivery with respiration and behavioral response recording.

Conclusions:

• The new portable olfactometer is a low-cost, user-friendly, and low-maintenance tool for brain imaging research.
• This system facilitates novel investigations into the neural basis of odor perception, particularly using event-related fMRI designs.
• It expands possibilities for studying olfactory responses in various experimental contexts.