From petrol and perfume to Parkinson’s disease, super-smellers can detect scents others are oblivious to. For Krati Garg, the ability’s both power and pain

A few years ago Dr Krati Garg, an oral surgeon in Melbourne, was in theatre about to commence work on a patient when she told the anaesthetist she could smell sevoflurane.

Sevoflurane is the anaesthetic gas used to put – and keep – patients asleep during surgery. Ingested via a tube that is placed down the throat, in large quantities its bitter smell can be noticeable, but trace amounts are largely indiscernible.

Police employ them and scientists study them, but what is life like for the rare few who can never forget a face? Super-recogniser Yenny Seo didn’t think it was anything special

As a child, Yenny Seo often surprised her mother by pointing out a stranger in the grocery store, remarking it was the same person they passed on the street a few weeks earlier. Likewise, when they watched a movie together, Seo would often recognise “extras” who’d appeared fleetingly in other films.

Her mother never thought this was “anything special”, Seo says, and simply assumed she had a particularly observant daughter.