Just noticeable difference in olfaction is related to trigeminal component of odorants.

Many studies have dealt with the interrelationships between both olfactory and trigeminal systems but a poorly explored question concerns the role of each system in the detection processes, especially in the just noticeable difference (JND). The aim of this study was to investigate variations in JNDs for three odorants in relation to their trigeminal component, i.e. low, middle, high. The results indicated that the higher the trigeminal component, the lower the JND, suggesting a better capacity to perceive intensity changes for pungent odorants than for relatively pure odorants.