Whenever we inhale, the receptors most closely matched to a particular scent will signal first.

But if you take a deeper sniff in that wineglass, you will inhale many more scent molecules, which can activate less specific receptors. Those added signals should dramatically change the scent, but they don’t, a riddle sensory neuroscientists call “concentration-invariance.”

— Read more at Fine-tuned Sense of Smell Relies on Timing: First impressions matter for precise scent identification at Duke Today.