Memory is unreliable. It twists, distorts, reshapes. But perhaps not Stephen Wiltshire’s, which appears to have served him better than a camera would. The 47-year-old British artist sketches cityscapes based entirely on his memory.

A video by Great Big Story for the series, Human Condition shows him drawing panoramic sketches of urban landscapes, with every detail in place. He is particularly inspired by skyscrapers, skylines and street scenes. Wiltshire works with considerable speed and incredible accuracy, headphones plugged in, fully immersed in his art.

And the most incredible thing of all: he needs just a glance at any landscape to get him going.

His pencil flies over the canvas and his sketches are snapped up just as rapidly by clients for thousands of pounds. Wiltshire holds a PhD in drawing and printmaking from the City & Guilds of London Art School, and in 2006, he was awarded an Most Excellent Order of the British Empire (MBE) for his services to art. In the same year, he opened a permanent gallery at the Royal Opera Arcade in London.

Wiltshire was diagnosed with autism when he was only three-years-old. A perceptive teacher spotted his talent in sketching and that set him on a fantastic journey. Armed with his pens, and a handy helicopter, Wiltshire often flies over cities, taking in the details and reproducing them in great detail. The artist has travelled the world, but his favourite city? New York, with its Art Deco buildings and yellow taxicabs.

The video below shows Wiltshire drawing the Mexico City skyline, while an audience watches him.