Have you heard of aphantasia? Here’s what it is — and how to know if you have it #TEDTalks

Picture this: a rocket ship crash-lands on a planet, and an alien approaches the spacecraft. What do you see in your mind when you visualize this scene? For Alex Rosenthal (and many others), the answer is: absolutely nothing. Exploring the fascinating science of aphantasia, or the inability to generate mental images, he shows why our minds are much more different than we think.