Effects of context on judgements of odor intensities in humans

This study evaluated whether the intensity of previously smelled odorscould unintentionally influence the subsequent judgement of odor intensity.The predicted context effect was based on the adaptation- level theory.Before and 25 min after either WEAK or STRONG biasing odor concentrations,51 subjects were required to rate the intensity of 10 different odorconcentrations of California Orange Oil. After the WEAK bias, subjectsjudged the odor intensity as being stronger than they did after the STRONGbias. Thus the intensity of odors smelled 25 min earlier canunintentionally influence subsequent odor intensity judgement. The findingsare discussed in the light of two alternative explanations, namely, acentral implicit memory process and a stimulus- level-based change at theperipheral level.