Chemesthesis Psychophysical Assessments
| Instrument | Function assessed | Substances used | Protocol | Advantages | Disadvantages |
|---|---|---|---|---|---|
| Stimuli lateralization108 | Lateralization | Benzaldehyde, eucalyptol | Subjects were presented with two bottles, one for either nostril. Bottles are filled with chemicals dissolved in propylene glycol or propylene glycol alone. A 15 mL puff of air from each bottle is simultaneously administered into one nostril. Subjects report which nostril was presented with the stimuli. | Simple administration, distinguishes olfactory function from chemesthesis | Requires clinician administration, protocol requires ∼30 minutes per stimuli |
| Odorant Detection Test110 | Detection threshold, discrimination, identification, lateralization | Camphor, diallyl sulfide, ethanol, eucalyptol, menthol, propranolol | Using felt-tip pens with chemicals dissolved in propylene glycol, subjects progress through identification of the sensation quality and triple-forced-choice procedure for discrimination for the 6 chemicals. Threshold and lateralization were assessed with menthol. Threshold was calculated as the mean of the last 4 of 7 staircase reversals. | Simple administration, similar protocol to Sniffin' Sticks | Not validatedRequires clinician administration |
| CO2 device111 | Pain responsiveness | CO2 stimuli with various durations (multiples of 50 ms) | CO2 stimuli is provided through standard nasal cannula in 10 seconds intervals. With each interval, stimulus duration is increased by 50 ms until the subject pushes a button, indicating a painful sensation. | Assesses “mass of a stimulus” rather than concentration | Not validatedRequires clinician administration |