Odorant quality perception: A metric individual differences approach

Perceptual spaces, in which similar stimuli are located close to each other and dissimilar stimuli are located far apart, have aided in the understand ing of the physiological and psychological bases for sensory quality coding . Differences in perception between individuals should be reflected by diff erences in the spatial relationships between stimuli. If the dimensionality of the perceptual space is small (e.g., color space), individual differenc es that reflect specific pathologies are readily apparent from visual inspe ction. On the other hand, if the dimensionality of the perceptual space is large (as is proposed for odor space), visual inspection alone may not reve al individual differences in quality perception. The present work presents an information-theory-based method for quantifying individual differences i n quality perception from perceptual confusion matrices. The ability of thi s method to quantify individual differences in quality perception is shown in a hypothetical example of specific anosmia. Finally, the method is appli ed to the examination of intrasubject consistency of odorant quality percep tion.