Octopuses Appear to Dream. What Does That Tell Us About the Evolution of Sleep?

Brazilian researchers recently learned that octopuses cycle through passive and active sleep stages, akin to how humans have REM and non-REM sleep stages. REM sleep is when humans do most of their dreaming. Does this mean that octopuses, perhaps, dream too? Sidatra Ribeiro, a neuroscientist at the Brain Institute at the Federal University of Rio Grande do Norte, tells us that studying the sea creatures can help us know more about how humans sleep and dream. (Segment produced by Aubrey Johnson)