I took my dog for a walk two nights ago, as I do every night. But this time, I took a different route to my friend Matias' house, and for the first time, I arrived from the opposite direction from the one I usually do. Dinamita --my dog--, who usually recognizes Matias' house and walks right into his backyard ahead of me, utterly failed to recognize the place, and walked right by. Once he had, I instructed him to turn around, and walking back in the usual direction, he recognized it immediately and walked right in.

It thus seems clear that dogs perform olfactory recognition using the spatiotemporal sequence of smells they perceive, not just static percepts. Which means that somewhere in a dog's brain, the order of smells matter.

Up to Science.