CrowdScience listener Eileen cannot see images in her head of her memories. She only discovered by chance that most other people can do this. She wants to know why she can’t see them and if it is something she can learn to do. Anand Jagatia finds out what mental images are for and whether scientists know why some people can’t create them. Three per cent of the world’s population cannot see mental images like Eileen. And it is only recently been given a name – aphantasia. Anand discovers why mental images are useful, why they are sometimes traumatic and how people who are blind or visually impaired can also create images of the world around them. Contributors: Emily Holmes, professor of clinical psychology, Uppsala University, Sweden Adam Zeman, professor of cognitive and behavioural psychology, Exeter University, UK Joel Pearson, professor of cognitive neuroscience, University of New South Wales, Australia Paul Gabias, associate professor, Department of Psychology, University of British Columbia, Canada Marijke Peters, Hannah Fisher and Jo Glanville, CrowdScience producers Presenter: Anand Jagatia Producer: Jo Glanville Editor: Richard Collings Production co-ordinator: Jonathan Harris Sound: Jackie Margerum Image credit: Andriy Onufriyenko | GETTY IMAGES | Creative #1397973635