Johnson, on Tuesday, described how she gets stage fright and was terrified to sing in front of others while shooting a scene for Our Friend. Johnson noted that she still had a panic attack despite the camera not being focused on her.
"They hit playback of my voice, my vocal recording and called action and it was like I had a panic attack that manifested in all the ways that it does, that it can. So, I just took off running," the actress said.
"Running like around the theater, around backstage. I was running around and then just started laughing hysterically and everyone on the crew's like, 'What's she doing?' Running around, laughing and then just stopped moving and started crying," she continued, before noting that the experience was like extreme flight mode.
Jason Segel and Casey Affleck also star in Our Friend, which is coming to theaters and video-on-demand services on Friday. The film, based on a true story, follows a couple dealing with cancer who have their best friend move in with them.
Johnson also played Dakota Settles It, a game where the 31-year-old gave her opinion on a variety of pop culture debates.
Johnson picked Team Edward over Team Jacob, Toy Story 3 as the best in the series and said Ross and Rachel from Friends were on a break.