Science Friday Edit this Published by Science Friday Can’t Stop Worrying? Blame It on Your Habenula Listen 6 min Queue Download this audio Want to embed this player? Use the code below. More info. <iframe frameborder="0" scrolling="no" height="130" width="100%" src="https://www.wnyc.org/widgets/ondemand_player/wnyc/#file=/audio/json/392233/&share=1"></iframe> Share on Facebook Share on Twitter Email a Friend The habenula is a pea-sized part of the brain that tracks our expectations of negative events.