Stress can cause sudden memory lapses when cortisol levels spike, especially in situations we can’t control. In an experiment, a job interview simulation sharply reduced test subject recall as cortisol rose. This fight or flight response disrupts the activities of the hippocampus, blocking access to stored information. Even professionals experience it, but deep breathing, distance and preparation can help get you back on the right path if your mind goes blank. Also in the show: we look at the budding field of smart textiles, check out building and packaging elements based on popcorn, learn how aquatic fungi play a vital role in creek and river habitats, and meet Veronika the tool-using cow.