Why Can't Some People Sleep Without a Fan?

Some people find it impossible to sleep without background noise, like a fan whirring. Researchers have identified the possible culprit. Learn how it works in this episode of BrainStuff.

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Episode Transcript

Speaker 1 (00:02):
Welcome to brain Stuff from How Stuff Works. Hey, there,
brain stuff, Lauren Vogelbaum. Here, chances are you know at
least a few people who rely on the whirr of
a fan to get a good night's rest. You might
be one of them yourself. And if you look closely
the next time you're checking into a hotel or waiting
to board a cruise, you may spy travelers touting their
own The effect that a fan provides during sleeping is

(00:24):
similar to white noise. We spoke with Kelsey Allen, a
sleep expert with mattress manufacturers sleep Train, in an email interview.
They said people who sleep with a fan are capitalizing
on what we call white noise. Just like white light,
which encompasses all the colors on the spectrum, white noise
encompasses all sound frequencies within typical human hearing. Technically true,

(00:45):
white noise is generated only electronically, but ambient noises like fans,
distant cicadas, or gentle rain can produce a similar effect.
So what's going on in the brains of folks who
need fans that makes them different from others? The answer
likely lies and how our brains are fired sleep spindles
in particular, seem to be the key. These are spikes
of neural activity that can be seen on electron cephalogram

(01:07):
tests a K A e G S and present as
short brain wave bursts that cause a spike or spindle
to form on the e G. Reading. Research indicates that
people who experience sleep spindles more often have a better
defense against outside noise than those who don't experience frequent
sleep spindles. And spindles don't come and go based on
what you eat for dinner or whether you're anxious about

(01:27):
something happening tomorrow. A person sleep spindle production is likely
to be static across time. How to sleep spindles accomplish
this enviable feat of blocking noise. These spindles are produced
in the portion of the brain called the thalamus, which
is the area that all sound and sensory information must
visit before being farmed out. Researchers think these spindles, these
spikes of neural activity actually run into the sounds and

(01:50):
block them from waking a person up. Since sleep spindles
are more common during R E M sleep, they're most
successful at completing this task during such phases. One study
out of Korea used optogenetics, that's control of both light
and gene expression to influence sleep spindle production in mice.
The scientists found that an increase in sleep spindles was
correlated with an increase in n R E M sleep

(02:12):
a k A deep sleep. Thus, they concluded that effective
modulation of sleep spindles could actually hold the key for
curing patients with sleep issues, though further research is required.
No one knows for sure why some people have rock
star sleep spindles while others suffer through the curse of
light sleeping. But it is often the change in sound
rather the sound itself that wakes up the brain. And

(02:33):
although you can get a white noise effect from a
sound machine or even a m radio static a fan
has the extra advantage of cooling you down. Notes Dr
Kevin Gaffney, a neurologist and sleep medical director at the
Emissioner Neuroscience Center. He told us your normal body temperature
of point eight degrees not nine point six, drops by
one to two degrees at night. If you have to

(02:54):
struggle to lower your body temperature, this can decrease your
sleep quality. Yeah. Today's episode was written by Alia Hot
and produced by Tristan McNeil. For more on this and
lots of other brainy topics, visit our home planet, how
stuff Works dot com