Why do certain smells trigger powerful memories?

Have you ever smelled a flower and been suddenly flooded with a childhood memory or did a certain smell of curry remind you of your grandmother? A new study has now decoded why and how the brain does this.

The researchers show that in humans there is unique connectivity between the hippocampus in the brain which plays a major role in learning and memory and the olfactory system (the sensory system used for smelling). Guangyu Zhou, from Northwestern University in Chicago, explains the process in detail in an email to The Hindu: “During evolution, primate brains (including humans) massively expanded, developing the neocortex. Due to this expansion, direct connections between sensory areas and the hippocampus also expanded...In our study, we compared how the olfactory system connects to the hippocampus with how other sensory areas (vision, hearing and touch) do. We found that olfaction had stronger functional connectivity with the hippocampus than these other sensory systems.” He is the first author of the study.