Have you ever felt a "presence" - someone next to you, even speaking to you, when no one is there? Dr. Ben Alderson-Day, a psychologist at Durham University in the UK, studies the phenomena of felt presences, or what he calls "the unseen other."

These experiences are not always symptoms of mental illness - these are universally reported and not always distressing. Learn what's happening in the brain during these hallucinations - or should we call them visitations? Plus... how the Internet brings together groups of people who can conjure up invisible friends, seemingly on command.

Full transcripts and additional resources available at: www.thisisyourbrain.com

For more about Dr. Alderson-Day's book, "Presence; The Strange Science and True Stories of the Unseen Other"

https://us.macmillan.com/books/9781250278265/presence