Scenario 10 – Optimal Fragrance Development
You are a sensory scientist working at a top British fragrance company where the latest trend is to develop an age-neutral fragrance. Some of the best-selling perfumes among the different age groups are based around aquatic or oceanic fragrances and utilise the odorant known as "watermelon ketone" which has an intense sea-breeze note with slight floral overtones. You are tasked with finding the perfect concentration of this odorant for use in the company's new fragrance that will appeal to a broad spectrum of ages.
You begin with a preliminary study utilising a magnitude estimation scale to rate the intensity of your fragrance samples in young and old participants. You have four samples of perfume with different concentrations of odorant, and participants can rate them using a simple scale (1-10; where 1=Weak, 10=Overpowering). You collected the following data based on testing a small group of individuals:
| Odorant concentration (mM/L) | 500 | 600 | 800 | 1200 |
|---|---|---|---|---|
| Older group Intensity Ratings |
1.2 | 2.1 | 4.0 | 6.4 |
| Younger group Intensity Ratings |
2.2 | 3.9 | 6.3 | 9.6 |
Plot the psychophysical functions for suprathreshold fragrance intensity for both young and old.
Which age group is more sensitive to the odorant? Explain your reasoning.
For a typical perfume, you do not want individuals to think it is too weak or too strong – somewhere in the middle would be just right. What approximate concentration of odorant would you choose for your new age-neutral fragrance based on the preliminary data you collected? Again, explain your reasoning.
If you were interested in finding a rough estimate of absolute detection thresholds of odorant for your young and old participants, explain how you might achieve this based on your data. Who would have the lower threshold?