Characterization of Retronasal Airflow Patterns during Intraoral Fluid Discrimination Using a Low-Cost, Open-Source...

Area of Science:

• Neuroscience
• Sensory Science
• Biomedical Engineering

Background:

• Nasal airflow is crucial for olfaction, involving sensorimotor processes for volatile delivery to the olfactory epithelium.
• Current methods for monitoring nasal airflow are often lab-based, limiting real-world behavioral studies.
• Wearable technologies are needed to better understand odor sampling behavior.

Purpose of the Study:

• To develop an inexpensive, wearable system for monitoring nasal airflow.
• To characterize retronasal airflow patterns during an oral fluid discrimination task.
• To investigate the role of sensorimotor processes in regulating airflow for olfactory perception.

Main Methods:

• Developed a lightweight, open-source brain-computer interface (BCI) system to monitor nasal air pressure.
• Assessed human participants performing an oral fluid discrimination task using the BCI system.
• Analyzed patterns of retronasal airflow, including rate, duration, and probability.

Main Results:

• Identified distinct patterns of retronasal airflow, characterized by sustained low-rate flow and higher-rate pulses linked to deglutition.
• Observed no significant differences in post-deglutitive pulse characteristics across different fluid conditions.
• Found increased cumulative duration, probability, and estimated volume of retronasal airflow when discriminating perceptually similar solutions.

Conclusions:

• A consumer-grade BCI system is effective for assessing human olfactory behavior.
• Sensorimotor processes actively regulate retronasal airflow to optimize volatile delivery to the olfactory epithelium.
• Discriminating between similar oral fluids may involve modulating the duration of optimal airflow rates.