A sequential contrast effect in odor perception

An odor of ambiguous quality was shown to shift in rated odor character after presentation of more prototypical odors, always in a direction contrasting with the previous context. The terpene aroma compound, dihydromyrcenol, is perceived as partially woody (pine-like) and partially citrus (lime-like) in odor character. Citrus ratings of this odor increased following exposure to woody odors. Conversely, woody ratings of dihydromyrcenol increased following exposure to citrus odors. Possible explanations for this sequential contrast effect include shifts in cognitive category boundaries, response frequency biases, and simple sensory adaptation.