When she goes to sleep at night, Alison MacAdam curls up with Baba, her soft, threadbare baby blanket. It's a bedtime ritual Alison has embraced for 40 years.

Alison is an editor at NPR, and when she told us about Baba we thought it was a little strange. Why would a successful, self-confident woman sleep with a blankie? But then, as we listened to her talk about it, we wondered if maybe it wasn't that strange at all. What's wrong with finding comfort in something soft and familiar?

This week, Hidden Brain considers the psychology of touch. First, Alison tells us the story of Baba. Then, Shankar interviews writer Deborah Blum about groundbreaking experiments into the power of touch and the importance of affection for young children.

Hidden Brain is hosted by Shankar Vedantam and produced by Maggie Penman, Jennifer Schmidt, Rhaina Cohen, and Renee Klahr, and Chloe Connelly. Our supervising producer is Tara Boyle. You can follow us on Twitter @hiddenbrain, and listen for Hidden Brain stories each week on your local public radio station.

Copyright 2017 NPR. To see more, visit http://www.npr.org/.