Poor Sleep on Your First Hotel Night: What Studies Found

You unpack, turn out the lamp and spend longer awake than you expected. Researchers call changes in sleep during an initial recording night the first-night effect. The familiar explanation about a brain keeping watch comes from a specific experiment, with narrower findings than the phrase suggests.¹

What the “night watch” experiment measured

The university account of the 2016 research describes three experiments involving 35 volunteers in total. Recordings took place on two laboratory nights a week apart. During the first night, the researchers found a left-right difference in the default-mode network during slow-wave sleep. Irregular beeps presented to the right ear produced greater waking responsiveness than those presented to the left.¹

The result concerned a particular network and sleep phase. Researchers examined only the first slow-wave sleep period, so they could not say whether the same side remained more vigilant all night. “Half your brain stays awake in hotels” goes beyond that finding. The experiment also supplied no estimate of how much sleep a woman would lose on a business trip.¹

Newer recordings complicate that explanation

A 2024 paper analyzed 45 healthy adults aged 18–31 on two laboratory nights a week apart. Average measured time to fall asleep was 20.37 minutes on the first night and 14.01 on the second. Self-reported sleep quality did not significantly differ.²

In a separate experiment, 30 participants contributed sleep-architecture data from two laboratory and two home nights, each a week apart. First-night changes occurred in both environments. Home recordings still involved attached electrodes and monitoring equipment.²

The authors found no relationship between their measure of left-right slow-wave asymmetry and the first-night effect. This challenges a single “one side keeps watch” explanation; it does not erase the earlier experimental finding. Their study used different recording methods.²

There are limits to the newer findings, too. Participants were healthy young adults without reported sleep problems, and the analyses did not correct for multiple comparisons. The authors acknowledge that some findings may be false positives. These are recording studies, without a tested hotel-sleep treatment.²

Has bringing your own pillowcase been tested?

A small 2019 conference abstract investigated that exact suggestion. Sixteen participants, ten of them women, averaged 20.3 years old. They spent one night in a hotel, followed by four nights at home. One group used a hotel pillowcase; the other used their own. Sleep quality was self-reported.³

The comparisons found no statistically significant differences in sleep quality, including between the pillowcase groups. With only 16 people and an abstract rather than a full trial report, this cannot establish that familiar bedding never helps. It also cannot support selling a pillowcase as a proven fix for the first-night effect.³

Pack yours if you prefer its feel. Treat that as a comfort choice, without a promised number of extra sleeping minutes.

Note whether the problem follows you home

A useful distinction for your notes is whether difficulty sleeping happens only on the first night away, continues across the trip, or also occurs at home. Record the morning outcome alongside the setting, rather than trying to infer which brain hemisphere was more active.

NHLBI recommends keeping a sleep diary and sharing symptoms with a healthcare professional. Include trouble falling asleep, repeated waking or waking too early, plus daytime sleepiness and difficulty concentrating. Repeated difficulty affecting daily life deserves that discussion even if the first episode happened in a hotel.⁴

Did I Do That in My Sleep? includes “Play One: Notice It” and a 14-Night Lights-Out Record. It uses approximate morning observations of sleep opportunity, waking and daytime effects. Add the location to distinguish travel nights from home nights; its fourteen-night format is an organizing choice, not a diagnostic threshold. See the book.