Sleeping poorly in an unfamiliar setting is a universal phenomenon that leaves people feeling restless. Traveling, staying in a hotel, or moving into a new home can disrupt the quality of rest. This difficulty in achieving satisfying sleep the first night away from a familiar bedroom is a biological reality. Understanding the science behind this temporary sleep disturbance can help you prepare for and mitigate its effects.
Understanding the First Night Effect
This initial struggle to sleep soundly in a new place is known as the First Night Effect (FNE). Researchers have determined this is not merely a psychological reaction, but a measurable neurological phenomenon based on an ancient survival mechanism. During the first night in an unfamiliar location, your brain does not fully shut down, exhibiting a “night watch” behavior.
This vigilance manifests as an interhemispheric asymmetry in sleep depth, meaning one side of your brain remains more active than the other. Studies have shown that a network in the left cerebral hemisphere stays more awake during slow-wave sleep (SWS), the deepest phase of rest. This partial wakefulness makes the brain more responsive to unfamiliar external sounds.
The heightened activity in this monitoring hemisphere is thought to be an evolutionary adaptation to detect potential threats in a novel environment. Because of this asymmetry, the first night of rest is characterized by a longer time to fall asleep and more frequent awakenings. This reduced depth and fragmentation of sleep means the overall quality of rest is lower than usual.
How Long Does Adjustment Take?
The duration of sleep disruption depends heavily on the context, but the most pronounced effects, the “night watch” asymmetry, typically disappear by the second night. The brain quickly adapts to the new surroundings once it recognizes the environment as safe, normalizing the depth of sleep during the second sleep session. However, full acclimation to a completely new environment, such as moving into a new home, can take much longer.
When settling into a new apartment or house, where there are entirely new ambient noises, smells, and light sources, your body may require several weeks to fully adjust. A complete adjustment period for a major life change like moving often falls within ten days to three weeks. Factors that extend this period include significant environmental differences, such as changes in local noise levels, or high levels of personal stress associated with the transition.
The purpose of the trip also influences the adjustment timeline. Traveling for a high-pressure business event creates anxiety, acting as an internal risk factor that makes it harder for the brain to switch off its vigilance mode. Conversely, a relaxed vacation in a quiet setting may allow the brain to acclimate faster, with the FNE resolving after the initial night. Individual factors, like being a “morning type” person or having a high sensitivity to sensory input, can make the adjustment period longer.
Practical Steps to Improve Sleep
You can actively work to minimize the First Night Effect by helping your brain perceive the new location as less novel and more secure. Begin by maintaining your regular bedtime and wake-up schedule as closely as possible, which helps anchor your internal clock. A consistent routine signals safety and predictability to your nervous system.
Creating familiarity is a powerful strategy that can help mitigate the brain’s vigilance. Bring comfort items from home, such as your own pillow, a familiar blanket, or a favorite scent, to introduce known sensory cues into the new space. These familiar objects reduce the feeling of novelty that triggers increased alertness.
Optimizing the new sleeping environment is important for encouraging deeper rest. Use earplugs or a white noise machine to mask unfamiliar sounds, which can trigger the more-alert brain hemisphere. Ensure the room is as dark as possible, using an eye mask if necessary, and adjust the temperature to a cool setting, typically between 60 and 67 degrees Fahrenheit, to promote the onset of sleep.
Dedicate time to a pre-sleep relaxation ritual to calm your nervous system before attempting to sleep. Avoid screens and stimulating work in the hour leading up to bed. Opt instead for mindfulness exercises, deep breathing, or reading a physical book. These actions help reduce hyperarousal and signal to your brain that the environment is safe for complete rest.