Olfactory Performance Can Be Influenced by the Presentation Order, Background Noise, and Positive Concurrent Feedback

Area of Science:

• Neuroscience
• Psychology
• Sensory Science

Background:

• The Sniffin' Sticks test is a widely used tool for assessing olfactory function, comprising threshold, discrimination, and identification subtests.
• Standardized procedures are crucial for reliable olfactory assessment, yet the impact of procedural variations on Sniffin' Sticks performance remains largely unquantified.
• Understanding how modifications affect olfactory test outcomes is essential for accurate clinical and research applications.

Purpose of the Study:

• To investigate the impact of modified testing procedures on olfactory performance using the Sniffin' Sticks.
• To compare the standard TDI (Threshold, Discrimination, Identification) order with a reversed IDT (Identification, Discrimination, Threshold) order.
• To assess the effects of background noise and concurrent positive feedback on olfactory test results.

Main Methods:

• A total of 120 participants were involved in three conditional experiments, with 40 participants per experiment.
• Experiments included comparing standard TDI order versus reversed IDT order, assessing the impact of nonverbal background noise, and evaluating the effect of concurrent positive feedback.
• Olfactory performance was measured using the Sniffin' Sticks test under these varied conditions.

Main Results:

• Reversing the subtest order to IDT resulted in significantly lower overall olfactory scores compared to the standard TDI order, particularly affecting the threshold subtest.
• Nonverbal background noise was found to decrease overall olfactory performance.
• Concurrent positive feedback demonstrated a modulating effect on the threshold subtest performance.

Conclusions:

• Deviations from the standard Sniffin' Sticks procedure, including altered subtest order, background noise, and feedback, significantly impact olfactory assessment outcomes.
• These findings highlight the sensitivity of olfactory perception to adaptation (altered order) and attentional distraction (background noise).
• The study underscores the importance of adhering to standardized testing parameters for reliable and valid olfactory function measurement.