Close your eyes and visualise the face of the person you love the most. The colour of their eyes, the texture of their hair, the detail of their skin. Can you imagine it? Philip can’t.

Although Philip, a 42-year old photographer from Toronto, is happily married, he can’t conjure up his wife’s face because he has no images of any kind in his mind’s eye. When he thinks about a face, it comes to him as an idea, as an intellectual concept, rather than a mental picture.

This newly described condition is called aphantasia and has prompted scientists to reexamine an experience that we so often take for granted – our imagination. What’s more, studying it is offering new insights into how we all might boost our visual imagery to improve our memory, increase our empathy and even gain new treatments for conditions like addiction and anxiety.