Olfactory Scene Analysis - Does Analytical Visual Processing predict superior identification of component odours in a complex mixture?

Background: Most familiar odours are complex mixtures of volatile molecules, which the olfactory system synthesizes into a perceptual whole. However, odours are rarely encountered in isolation and thus, the brain must also separate distinct odour objects from complex backgrounds. While in vision, individual differences in scene analysis have been widely reported, to date, little attention has been paid to the cognitive processes underlying this olfactory ability. Aim: The aim of the present study was to determine whether local processing performance in visual tasks, would predict participants’ ability to identify component odours in multicomponent mixtures. Methods: 59 participants (F=39), aged 16-55, completed two visual perception tasks, (Navon and Block Design) and an odour-mixture task designed to test participants’ ability to identify multi-component odour objects in binary/ternary mixtures. Results: Performance on the Block Design Task was not significantly associated with odour mixture task performance. However, on the NAVON, faster overall reaction times and lower accuracy on global incongruent trials, suggestive of greater local interference, was significantly predictive of binary odour mixture performance. Conclusion: These results provide initial insight into the cognitive processes required for olfactory scene analysis.