Odor quality profile is partially influenced by verbal cues.

Jisub Bae,Ju-Yeon Yi,Cheil Moon,Johannes Reisert

doi:10.1371/journal.pone.0226385

Abstract

Characterizing an odor quality is difficult for humans. Ever-increasing physiological and behavioral studies have characterized odor quality and demonstrated high performance of human odor categorization. However, there are no precise methods for measuring the multidimensional axis of an odor quality. Furthermore, it can be altered by individual experience, even when using existing measurement methods for the multidimensional axis of odor such as odor profiling. It is, therefore, necessary to characterize patterns of odor quality with odor profiling and observe alterations in odor profiles under the influence of subjective rating conditions such as verbal cues. Considering the high performance of human odor categorization, we hypothesized that odor may have specific odor quality that is scarcely altered by verbal cues. We assessed odor responses to isovaleric acid with and without verbal cues and compared the results in each stimulation condition. We found that verbal cues influenced the rating of odor quality descriptors. Verbal cues weakly influenced the odor quality descriptors of high-rated value (upper 25%) compared to odor quality descriptors of low-rated value (lower 75%) by the survey test. Even under different verbal cue conditions, the same odor was classified in the same class when using high-rated odor quality descriptors. Our study suggests that people extract essential odor quality descriptors that represent the odor itself in order to efficiently quantify odor quality.

Highlights

Characterizing odor quality is important as humans can quantify differences between smells in order to predict odor quality
We performed odor descriptor survey tasks of B-isovaleric acid (IVA), C-IVA, and Vomit” verbal cue (V-IVA) conditions in order to examine the effect of verbal cues
We found that C-IVA had significantly different identification and pleasantness patterns from B-IVA, V-IVA was similar to B-IVA (S1 Fig, S1 and S3 Tables)

Summary

Introduction

Characterizing odor quality is important as humans can quantify differences between smells in order to predict odor quality. Presenting verbal cues with odor stimulation alters odor responses, suggesting that odor perception is significantly influenced by verbal labeling [19]. These studies suggest that subjective rating can be influenced by individual experience and that measuring odor profiles is less accurate than other methods involving behavioral or neurological approaches [5, 9]. It is, necessary to characterize alterations of odor profiles stimulating odor by influencing subjective rating conditions. It is hard to understand how severely the odor profiles are altered by conditions, people can predict the amount of severity using negative controls such as Hep

Materials and methods

Participants

Results

Discussion and conclusions