Newly discovered brainwaves – coined Princess Leia waves – that cycle around the brain as we sleep, may help us remember the day's events. Terry Sejnowski at the Salk Institute for Biological Sciences in La Jolla, California, coined the name after discovering patterns of electrical activity that sweep through the sleeping brain in a circular motion that resembled the headphone-like hairstyle made famous by Carrie Fisher in the Star Wars movies. The waves began their journey in the hippocampus – a region responsible for memory retrieval. From there they propagated to the thalamus, an area that is known to incorporate information vital to our ability to remember events that happen to us personally, before heading to the cortex, which is responsible for complex functions such as thoughts and actions. Sejnowski discovered the circular waves by chance after analysing electrical data from eight people with epilepsy who'd had electrodes temporarily inserted into their brains to monitor activity associated with their seizures.