Science editor Ian Sample sits down with co-host Madeleine Finlay and science correspondent Hannah Devlin to hear about three eye-catching stories from the week, including a study showing that the brain has five ‘eras’, with adult mode not starting until our early 30s. Also on the agenda is new research showing the shingles vaccine not only protects against dementia but could actually slow its progress, and a paper exploring how ants sacrifice themselves when they become infected with pathogens to protect their healthy relatives