Ever wonder where "brain freeze" comes from?
What about the hiccups? How about goose bumps? While you might not spend much time thinking about these strange body phenomena, they're fairly complex neurological events. In some cases, they serve important biological functions (or they did at one time).
James Giordano, PhD, is a professor in neurology and biochemistry at Georgetown University Medical Center. We spoke with him to discuss some of these strange neurological phenomenon—and to find out, once and for all, how to get rid of the hiccups.
For instance, we learned that…
Scientists have several theories regarding "brain freeze."
We've all been there: You're eating ice cream or slurping on a milkshake when you're suddenly hit with an intense wave of pain.
In other words, you're overloading an extremely sensitive part of your mouth, and you're not giving your brain enough time to recognize the rapid change in temperature. The effect is immediate—and for some people, almost unbearably painful.
"What ends up happening is that, when you have something very cold in your mouth, it will cause a rapid construction of the blood vessels in and around the nerves at the roof of your mouth," Giordano explains. "That change in the constriction and dilation sends a very, very strong signal to the brain that it's a painful input.
"It's called a sphenopalatine ganglioneuralgic event."
After taking about 20 minutes to learn how to spell "sphenopalatine ganglioneuralgic event," we asked the professor: Once your brain stops freezing, how do you stop the pain?
"It's real easy to fix," he says, "Just take your tongue, which is quite warm, and press it against the roof of your mouth for about five to 10 seconds. Or drink something that is at least 10 to 15 degrees warmer than whatever it is you put in your mouth.
"This helps to resolve the hyperstimulation that likely causes brain freeze. We say "likely" because up until a few years ago, there was another theory.
"The old theory held that rapid constriction of the blood vessels diverts blood flow to a major artery of your brain, and that blood vessel constricts, then rapidly opens up to increase blood flow to your brain," Giordano says. "It seems likely that it's probably not the case. It's probably due to a hyperstimulus."
In case you're wondering, yes, there are scientists studying brain freeze. We like to picture study participants laying in MRI machines while frantically licking ice cream cones.
"You'd be amazed at what people do for grant money," Giordano jokes. However, he quickly adds that this type of research can be quite important.
"For some people, [brain freeze] can be very severe," he says. "Even relatively cold stuff can make some people very sensitive. It does represent something that's study-able—it's not trivial."
In fact, some researchers believe that studying brain freeze may provide some insight into other types of neurological events, including more severe headaches such as migraines.
Hiccups are pretty easy to explain—and remarkably easy to fix.
"It's a phrenic and vagus nerve discharge activation," Giordano explains. "A number of different things can cause [hiccups], such as rapid filling of the stomach or displacement of gas in the stomach. Additionally, consuming something something very cold, very hot, or very spicy can cause a neurological discharge, not only in the stomach, but in the soft palate."
That leads to a fairly unpleasant sensation.
"You get an diaphragmatic spasm," Giordano says. "We experience that as a hiccup. It's basically just a response to evocative stimulation of the soft palate and/or top of the throat and top of the stomach."
In layman's terms, your stomach is overwhelmed, so your diaphragm spasms. Most hiccups stop within a few minutes, but they can be persistent. We asked whether hiccups serve any sort of biological function.
"It's really just a response to that level of stimulation," Giordano says. "It's usually just a minor inconvenience, but for people who chronically hiccup, the force of contraction can be really bothersome."
Chronic hiccups can be debilitating, and they can indicate a range of serious medical conditions including pneumonia, pancreatitis, and hepatitis. They can also occur due to neurological damage, and in some cases, they're not easily curable. One unfortunate man named Charles Osborne had the hiccups for 68 years, likely due to brain damage sustained while weighing a hog (you can't make this stuff up). The hiccups gradually slowed before stopping one year before he passed away.
Most hiccup attacks aren't quite so severe, and they're fairly easy to treat."For non-pathological hiccups, there's a really easy way to cure them for 99 percent of the population," Giordano says. "You want to sit down and bend forward at the waist, and I mean really bend forward...Then, drink a room-temperature, non-carbonated fluid for 10 seconds straight, or 8–10 swallows of fluid. Stay in that position until you're finished, then slowly sit up."
Why does that work?
"It's sort of a neurological override," he says. "The swallowing reflex requires coordination of a number of different nerves, and you're literally overcoming the spasm by super-coordinating a pattern response."
That explains some folk remedies, including one that requires biting on a lemon soaked in aromatic bitters. The bitters overstimulate the nerves, while the acid from the lemon acts as a binding agent. Giordano says that other home hiccup remedies may have similar results.
"I'm a big fan of home remedies," he says. "It's a form of family science—people experiment, and if something doesn't work, the remedy doesn't get passed down."
Ever wonder why your entire body suddenly jerks awake while you're falling asleep?
That phenomenon is called a hypnic (or hypnagogic) jerk, and it's often accompanied by the sensation of falling.
"As you're beginning to fall asleep or change your level of consciousness, basically you're becoming what's called hypnagogic," Giordano says. "You're getting progressively more relaxed."
"As your muscles begin to relax, the muscles are stretching. In each and all of our muscle fibers, we have stretch receptors, or spindle fibers. As our muscles expand, we contract them very subtly throughout the course of the day. This helps us to maintain our posture."
"As we fall asleep, our muscle tone begins to lessen, and we get an elongation of muscles. However, if we're not fully asleep—if our body relaxes a little bit faster than our brain does—our brain attends to that feedback; it says, 'Hey, we're getting this stretch response. We're either falling or overextending our muscles.'"
"Our bodies introduce a rapid compensation response, which is a twitch." To put that another way, our brains and bodies aren't in sync.
Is there a way to prevent this from happening? "It really depends," Giordano says. "For some people it's really natural. It happens to me just about every night...There's really nothing there to predict it, it's a fairly natural thing."
"If it's bothersome for some people, stretching before you go to bed may be helpful. It preloads the system to anticipate the stretch. A hot shower or a hot bath, which is very relaxing, can introduce a similar relaxation effect. And for some people, if the effect is very severe and/or happens frequently, a solution may be consult with their physician to provide certain medications. But this is usually reserved for more extreme cases."
Researchers generally agree that substances like caffeine can increase the chances of a hypnic jerk, as can physical or emotional stress, so lifestyle changes can be an effective treatment. Medication is a last resort, but if you're having serious issues sleeping, talk to a sleep specialist.
Ever hear strange sounds while falling asleep?
Some of those sounds might be real—well, in a sense.
"There are three sets of bones that make up the hearing apparatus. Sound comes into the ear, displaces the eardrum, and that causes these little bones to move," Giordano says. "Those bones actually have ligaments in between them, and very, very small muscles that form a ring around them."
"For some individuals, as the muscles relax, the level of tone will change, as will the way we process sound. We have two effects: a mechanical effect and a neurological effect."
That can result in hypnagogic claps, to use medical terminology, or "sleep booms," to use a term we just made up. Basically, as the tiny muscles relax, your brain "hears" a sound. In some cases, the sounds are unsettling.
"Many people worry when they hear rustling noises," Giordano says. "They might think they're having hallucinations."
Hallucinations, by definition, occur when a person is fully awake, but while you're sleeping, you might experience something similar to a hallucination. Just prior to REM sleep, the brain can easily misinterpret stimuli. Rustling sounds, for example, might become whispers.
"The distinction between real sounds and early-stage dream sounds becomes blurred," Giordano notes. "But it's very common to hear sounds while drifting off to sleep."
Goose bumps are probably an evolutionary throwback.
"To understand the goose bumps is to understand the pee shivers," Giordano says.
Don't worry, we'll get to the pee shivers in a minute.
"The base of every hair on your body is a little muscle known as the arrector pili muscle," he says. "... What happens is that some stimulation causes a piloerector effect."
That produces something called horripilation, commonly referred to as "goose bumps" or "goose flesh." The muscles surrounding each hair tense up, pushing the hair straight out. Cats do the same thing; when frightened, their hair puffs out to make them look more intimidating.
"This is essentially an evolutionary throwback to when we were much hairier creatures," Giordano says. "The reason this is important is our 'coats,' if you will, do a number of different things. Certainly, they can be used to keep us warm, but we can also use our coats as an ornament. If we get excited, aroused, or angry, we want to change our appearance. One way we can do this is puff ourselves up."
"For humans, it happens to us when we encounter extremes of temperature because we're having this vestigial response."
Certain emotions will cause a similar response. The sympathetic nervous system, which controls our fight-or-flight response, increases activity. That causes a change in heart rate, which our bodies might interpret as a physical chill. Now, about those pee shivers…
Yes, we're actually going to explain the pee shivers.
The pee shivers are similar to goose bumps; they're an activation of our fight-or-flight responses.
"[The fight-or-flight response] increases the tone to our muscle, and we feel that as a shiver—we feel that contraction," Giordano says. "For some people, it also changes their level of vasodilation, and it'll open up the blood vessels to the core and to the muscle and change the blood flow to the extremities. They may actually perceive a chill running through them."
What does that have to do with urination? That depends on what type of pee shivers you're getting.
"There's two kinds: the 'I gotta pee' shivers and the 'I just finished' shivers," Giordano says. "The 'I gotta,' that's pretty easy. Your sympathetic nervous system is pretty jazzed. It's stressed. The more your bladder fills, the more force it takes to keep the little muscle contracted. You're keeping force on that muscle, and that becomes stressful, so sometimes you get one of these shivers."
The "I just finished" shivers are a bit more complex, neurologically speaking.
"Your body has gone from primarily using its sympathetic nervous system to its parasympathetic nervous system, which causes you to shiver," he says. "Your nervous system's trying to reset itself. It doesn't happen to everyone, nor does it happen to everyone all the time. What will often happen is that your bladder will be very full. It's that level of relaxation that then gives you the shivers."
The parasympathetic nervous system, by the way, controls "rest-and-digest" functions. And you thought that your pee shivers were boring.
In case you're wondering, there's a scientific name for this phenomenon: post-micturition convulsion syndrome. The Wikipedia page for said syndrome notes that "several studies by companies have documented pee shivers," but we couldn't track them down. We did find evidence of one case report, which, sadly, isn't available online. We're imagine it says something like, "Patient vows to always put the toilet seat up for the rest of his natural life."
Still, we're comforted by the idea that out there, somewhere, scientists are working hard to understand things like pee shivers. Our bodies aren't always easy to explain, especially when bodily phenomena become somewhat taboo, but hard-working researchers are doing their best.
It's enough to give you goose bumps—or pee shivers, for that matter.