Olfactory object recognition based on fine-scale stimulus timing inDrosophila

SUMMARY Odorants of behaviorally relevant objects (e.g., food sources) intermingle with those from other sources. Therefore, to sniff out whether an odor source is good or bad – without actually visiting it – animals first need to segregate the odorants from different sources. To do so, animals could use temporal cues, since odorants from one source exhibit correlated fluctuations, while odorants from different sources are less correlated. However, it remains unclear whether animals can rely solely on temporal cues for odor source segregation. Here we show that 1) flies can use a few milliseconds differences in odorant arrival to segregate a target odorant from a binary mixture, 2) segregation does not improve when the target odorant arrives first, and 3) segregation works for odorants with innate, as well as learned valences. These properties of odor segregation parallel those of concurrent sound segregation and figure-ground segregation by onset asynchrony in humans.