Scents and Scents-ability

Is this milk still good to drink?

This is Sandra Tsing Loh with the Loh Down on Science, saying….

I’ll just sniff…ohh ugh no! Down the sink it goes!

Our sense of smell helps us avoid expired milk – and other dangers! But how do our brains process these stinky odors? Is it different from GOOD smells, like our morning coffee?

Enter Behzad Iravani from the Karolinska Institute in Sweden and team. 

They exposed twenty volunteers to six smells–some fun like pineapple, some strong like onions. They used electrodes to measure electrical activity in the subjects’ brains while they sniffed. 

Afterwards, the volunteers rated the smells from best to worst. Researchers compared brain activity triggered by the two best and the two worst smells.

And? Foul odors triggered brain activity within two hundred milliseconds! But GOOD smells? They took more than THREE TIMES longer! 

Iravani says this means our brains prioritize bad odors, fast-tracking them to protect us from danger.

Well that just makes…perfect SCENTS!

Reference: Iravani, B., Schaefer, M., Wilson, D. A., Arshamian, A., & Lundström, J. N. (2021). The human olfactory bulb processes odor valence representation and cues motor avoidance behavior. Proceedings of the National Academy of Sciences, 118(42).

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