Smell has a direct line to your memories

You cross paths with a perfume, the smell of a stew or the pages of an old book and, all at once, you're somewhere else, in another time. It's no accident: smell is wired to the brain in a unique way.

The other senses, sight or hearing, make a stop at a kind of switchboard, the thalamus, before reaching the areas that interpret the information. Smell skips that step. Signals from the nose go almost straight into the regions that handle emotion and memory, the amygdala and the hippocampus.

That's why a smell isn't just recognised: it's felt, and it drags a whole memory along with it, often more powerfully than a photo.

You have a secret button for time travel. It sits right between your eyes, and you press it every time you breathe.