When sleeping in an unfamiliar setting for the first time, it’s likely to take longer to drop off to sleep, and the sleep we do finally get will be broken and unsatisfying. It’s a phenomenon scientists refer to as “first-night effect” (FNE), Although it’s been a part of the human experience since humans first slept in a new cave, the science behind it has remained a mystery. In 2016, researchers set out to find out why FNE occurs and whether there’s any benefit to it. What they discovered was that during the first night of sleep, the left side of the brain is significantly less asleep than the right — the two hemispheres don’t sleep in equal amounts, displaying different patterns. The more different the two sides of the brain behave, the longer it takes to nod off. So, are there any benefits? Having a degree of control over this phenomenon might be useful for people who often travel for work because over time their brains would likely adjust. Sleep holds many mysteries, so digging into FNE is going to require further investigation.
