The Science Behind Why You Can't Fall Asleep in a New Bed

August 11, 2022 | Casper Editorial Team

Fact checked by Casper Labs Review In Progress

The lights are out, you’re snuggled up in a cozy cocoon of comforter, and all of a sudden, you’re wide awake despite nestling into a brand new bed. 

If you can’t fall asleep in a new bed, it may be the result of the first-night effect (FNE), a scientific phenomenon that causes part of your brain to remain active and awake as the rest of your body drifts off.1

Looking to learn a little more about this nightmare-ish sleep issue? Stay awake a little longer to read on—we’re exploring the first-night effect, related sleep issues, and the potential solutions to help you get the best night’s sleep imaginable. 

What Is the First-Night Effect?

As mentioned, the first-night effect is a common cause of restless evenings on new mattresses. Even after breaking in a mattress, and incorporating your a solid bedtime routine, those experiencing FNE may find themselves struggling to fall asleep, waking up frequently during the night, and rising in the morning feeling groggy and unrested.

Even if you’ve picked up an award-winning mattress, specified to your specific wants and needs, you may still experience the odd restlessness associated with FNE.

Additionally, FNE isn’t limited to bringing a new mattress into your home. You might experience the sleep issue of FNE in other circumstances including:

  • Sleeping at a friend’s home
  • Staying in a hotel
  • Rearranging your sleep environment

Essentially, anytime you change your sleeping arrangements, you run the risk of FNE.

How Does FNE Impact Your Brain?

If you’re reading, it’s likely that you’ve already experienced the symptoms of FNE. Whether you’re staying out of town, experience insomnia, or have just set up your new mattress, you may be intimately familiar with the odd restlessness and poor sleep associated with this phenomenon.

In fact, if you travel regularly, you might run into this sleep problem frequently. That said, you might be unfamiliar with the neurological factors behind the sleep problem of FNE.

Curious about how the first-night effect works in your brain? Consider the following.

Right Brain/Left Brain Split

Our brains are divided into two hemispheres: the right and the left. Without diving into the complicated world of brain biology, we can make a few clear distinctions between these two areas of the brain:2

  • Imaginative right side – Some research suggests that the right hemisphere of the brain is responsible for many artistic and imaginative processes. From admiring paintings to daydreaming, the right side may play a part in our visualization of emotions and feelings, allowing for abstract thinking and non-verbal understanding.
  • Logical left side – Calculations, sequencing, and fact-finding is typically associated with the left side of the brain. The structures responsible for logical thinking and reasoning may be more prevalent in the left hemisphere, and non-visual, mathematical thinkers may significantly rely on the left side of the brain for these crucial functions.
  • No simple split – The hemispheres of your brain don’t function independently. There’s plenty of overlap and connectivity between them. While it’s common to refer to someone as ‘left-brained’ or ‘right-brained’ regarding their particular personalities, in truth we all use both hemispheres at the same time.

What’s the connection between brain hemispheres and FNE? Research has suggested that those experiencing this phenomenon appear to have more active left hemispheres, while the right hemispheres are mostly asleep.3 It would appear that the logical functions of the brain are kept on alert even when the body is trying to settle into a new cozy bed.


Why might the left side of the brain remain active during FNE? It would seem strange, after all, that your brain is interested in logical processes and facts when it should be fast asleep, creatively dreaming up your next midnight mirage. 

Potentially, the biggest factor and internal reasoning for FNE is an instinctual need to stay alert and vigilant to protect yourself from predators.

Yes, despite you being cozy under your new duvet with a sleep mask, the oldest structure in your brain may still be thinking like a cave person. Throughout human development, we’ve needed to remain active and alert even during restful periods, and despite building up a significantly different civilization over the past few thousand years, our brains are still adjusting.

Hypervigilance—an elevated sense of awareness of your surroundings—may have the following impact on you as you try to fall asleep on an unfamiliar bed:

  • Noise sensitivity – Many of us are jolted awake by our alarms in the morning, but if you’re dealing with sleep issues, the smallest creak or squeak is enough to wake you up. This reaction would’ve been useful if a lion was roaming around your home and not just your pet cat.
  • Light sensitivity – If you’re dealing with FNE, the flash of a bathroom bright light from the corner of your eye may leave you feeling wide awake. According to a sleep expert, one part of your brain is highly aware of any changes in your surroundings, while the other is desperate for a little rest and relaxation.

Additionally, you may find yourself bolting straight up in the night, without a single sight or sound to blame it on. It could simply be an involuntary brain reaction to an unfamiliar situation. 

Excessive Exhaustion

The brain needs good sleep, and FNE can drastically reduce the amount of restful,  deep sleep you receive. Fortunately, it’s usually a temporary phenomenon, allowing you to return to a normal sleeping pattern quickly and catch up on all that much-needed shut-eye.

That said, even one night of restless sleep can have the following effects on your mind and body:

  • Cognitive impairment – “Sorry, I didn’t sleep well last night,” is one of the most common phrases to hear after a messy presentation, a missed meeting, or confusing communication. That’s because a lack of good sleep can directly impact your ability to think and concentrate, making work a real doozy after a fitful sleep.
  • Memory issues – Retaining and recalling information can become more difficult without a full night’s sleep. After a night in an unfamiliar place, you may be more likely to struggle remembering names, dates, and even what you did the day before.
  • Reduced coordination – Your mind and body may both feel slow and less coordinated after poor sleep. This could impact your response times and leave you feeling clumsy and less alert.

Perhaps the most obvious effect of FNE is feeling sleepy all day long. It can take days to recover from sleep debt, turning a one-night problem into a week-long issue. It’s nothing to see a doctor about, but it could be a major inconvenience if you have a demanding week ahead of you.

What Is the ‘Dolphin Effect’?

You may have a lot more in common with aquatic mammals than you originally thought. While dolphins are well known for their intelligence and human-like communication skills, they may also have similar brain structures when it comes to sleeping.

The first-night effect has also been referred to as ‘the dolphin effect’ or ‘dolphin mode.’ It may sound a little odd until you examine the similarities between this scientific phenomenon and the way dolphins sleep. 

Notably, dolphins are capable of fully resting while part of their brain remains awake. While humans can rely on our non-conscious brain functions—known as the involuntary nervous system—dolphins don’t have the same luxury. 

Instead, they need to keep part of their brain active to ensure their breathing continues even while they’re sleeping. This process, known as unihemispheric sleep, is somewhat similar to the first-night effect.2

Strategies For Mitigating FNE

If you’ve found yourself in an unfamiliar bed and you’re hoping for restful sleep, there are a few crucial ways to minimize the chances of FNE and other sleep disturbances related to new mattresses. 

Firstly, if you’re opting to change your mattress at home, be certain to choose a high-quality foam mattress that can deliver the support you need, night after night.

Additionally, you might keep the following suggestions in mind:

  • Keep your sheets (at least for a little while) – When switching over to a new mattress, you might be tempted to change your sheets as well. A fresh start for your sleeping routine could be great, but it could also contribute to FNE. On the other hand, using your old sheets with a new bed might help minimize the feeling of unfamiliarity and make falling asleep a little easier.
  • Take your pillow – When traveling, it can be helpful to bring something associated with your bed with you. Your pillow is a natural choice to providing a familiar feeling to a new sleep environment.
  • Give it time – Humans are highly adaptable, so don’t let your sleep issues get you down for too long. In most cases, giving your body a little time to adjust is all you’ll need to start sleeping the whole night through. You can expect up to a thirty-night adjustment period as your body acclimates to a new mattress.

Find a Better Night’s Sleep with Casper

Falling asleep quickly and regularly is an important part of cultivating a healthy sleep routine. If you can’t sleep on a new mattress, there’s plenty you can do to help your body and mind adjust. 

Additionally, if you’re struggling with deep sleep due to your mattress, there’s a simple way to start sleeping better ASAP invest in a good mattress with Casper.

At Casper, we’re in the business of making bedtime better. Not only have we designed innovative mattresses that prioritize comfort, support, and cooling, but we also deliver them directly to your door in a convenient box. Plus, with bed frames, bedding, pillows, and more, you can find everything you need for a great night’s rest today at Casper


  1. NPR. Half Your Brain Stands Guard When Sleeping In A New Place. 
  2. Healthline. Left Brain vs. Right Brain: What Does This Mean for Me? 
  3. Smithsonian Magazine. You Can’t Sleep While Traveling Because Your Brain Acts Like a Dolphin’s.
  4. Cleveland Clinic. Here’s What Happens When You Don’t Get Enough Sleep (and How Much You Really Need a Night).
  5. Scientific American. How do Whales and Dolphins Sleep Without Drowning?