If you've ever had the sheer pleasure-slash-terror of being woken up mid-REM cycle thanks to the random mutterings of your bed mate, you've undoubtedly spent a minute or two of your lifetime pondering this very question: Why do people talk in their sleep? You'd be in good company, too — a cursory glance at online forums and search results yields many queries from unsuspecting soul who want to know what causes these nighttime outbursts.
For that matter, I am one of them, thanks in large part to my husband's frequent and seemingly inexplicable declarations. Granted, he's no Sleep Talkin' Man, but he has his moments. Like the night he wailed in my direction, "Why would you do this to me?" Or the sleepless (for me) evening he bolted upright in bed and eerily seethed, "All of the eligible orders must die," before quietly rolling back over and leaving me to wonder if I fell into one of those ill-fated orders. Or — my personal favorite — like the time he fell asleep in his favorite chair only to awaken abruptly, shouting, "It's time for explosive eye drops!" Yes, I have invested considerable time staring at the ceiling in the dark considering why people talk in their sleep.
So are my husband's nighttime mutterings indicative of some tucked away emotions or reflective of the dark recesses of his restless mind? Meh, probably not. But before we delve into that, let's begin by taking a closer look at how scientists define sleep talking.
What is Sleep Talking?
The National Sleep Foundation explains sleep talking as "a sleep disorder defined as talking during sleep without being aware of it." Also known as somniloquy, sleeping talking falls into the category of parasomnias — sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and/or dreams. Other examples of parasomnias include teeth grinding, night terrors, and sleep walking.
Can It Be Dangerous?
Well, that depends — one cannot rule out a wallop from an understandably tired and cranky bed mate at their wit's end. I kid, I kid. In fact, experts theorize sleep talking isn't physically harmful. However, it can be indicative of more serious sleep conditions such as sleep apnea and sexomnia (whereby one has sex whilst sleeping), so it's always a good idea to discuss it with your primary care doctor. Aside from that, the only real danger is the sharp twinge of embarrassment the sleep talker may feel when discussing their nonsensical outbursts around the breakfast table the following morning.
Is There a Course of Treatment?
Because sleep talking bears no real threat to the person doing it — barring the more serious aforementioned sleep conditions — no treatment is typically necessary. However, proactive approaches to minimizing the likelihood of occurrences include getting a good night's sleep, adhering to a sleep schedule, and practicing proper sleep hygiene. Wait, what is sleep hygiene? This is just a fancy way of describing the myriad different practices necessary to achieve normal, quality nighttime sleep.
Who is Afflicted By It?
While experts estimate that nearly half of all children and up to five percent of the adult population experience sleep talking, there is little definitive information on why it affects certain people and not others. It may hinge largely on various environmental factors, which leads us to our last question and the query at hand.
What Causes It?
Sleep talking can occur in both REM and non-REM sleep phases, as well as during the half-awake transition between the two — a period known as "transitory arousal." When it does occur during REM sleep, researchers say it is the result of "motor breakthrough" of dream speech. In other words, a switch in your brain gets flipped on, briefly causing your slumbering mouth and vocal cords to actually speak the words from your dreams out loud. And while scientists posit that sleep talking may be the result of stress, depression, anxiety, sleep deprivation, and even alcohol consumption, they have found that — for the most part — sleep talking consists of brief, nonsensical utterances. Hence, explosive eye drops.