The human body — and mind — is an amazing device. I often wonder why our body reacts certain ways, and came up with some curious questions I had to investigate.
Why Do Some People Sneeze When Looking at the Sun?
Studies show about 25-35% of people sneeze or get the urge to sneeze when looking at the sun (or another bright source of light). There have been certain names designated for “sun-sneezing” from photic sneeze reflex to ACHOO (autosomal-dominent compelling helioopthlmicoutburst).
Sneezing is a reflex, so it happens without a person even having to think about it. Sneezes are actually breaths that occur at speeds of up to about 100 miles per hour. No one is really 100% sure why some people sneeze when looking at bright lights, but some experts suggest it may have something to do with sensitivity to light, or caused by some of the nerves getting mixed up in the brain. Since the pupils dilate and contract in different light settings, and those nerves are near the sneeze reflex nerve (the trigeminal nerve), which might activate a sneeze.
Why are Yawns Contagious?
Most people will yawn when they see others yawn, even if it’s a pet or another animal doing it. Some people even yawn when they read about or hear the word. What is so powerful that draws us to yawn on such slight cue?
This phenomenon has to do with something called the “mirror-neuron system.” According to WorldScience.net, “[b]rain cells, or neurons, become active both when their owner does something and when he or she senses someone else doing the same thing.” Also according to the site, it was noted there is a “deactivation of a second brain area, called the left periamygdalar region. The more strongly a participant reported wanting to yawn in response to another person’s yawn, the stronger was this deactivation.”
Some researchers think contagious yawning stems back centuries ago to early humans who had less verbal communication and used yawning as a sense to express their alertness level (or lack thereof), thus in a way to synchronize sleep schedules and such.
What Causes Hiccups?
A hiccup is an involuntary contraction of your diaphragm. During normal breathing, inhaling contracts the diaphragm while exhaling relaxes it. Exercise, stress, and indigestion have been noted to cause hiccups, and sometimes there is no apparent reason for developing this reflex.
Some people claim many things work to cure hiccups. Some examples include holding one’s breath or scaring someone experiencing them. Sometimes these remedies work for some people, and it’s probably because these are things that halt the rhythm of respiration.
Why Can’t a Person Tickle Themself?
It all boils down to this: it is expected, so the brain notices it less, or focuses on it less. Tickles are often partly responded to because they include an element of surprise and reaction to that as well as sensation from another person’s touch. We cannot surprise ourself, we expect our own touch, and we are familiar with our own touch.
What Exactly is “Brainfreeze?”
We’ve all probably quickly eaten or drank something ice cold and gotten a headache or a tight sensation in our heads afterwards. This “brainfreeze” sensation is due to cold contacting the roof of the mouth, which is filled with nerves. One nerve in this region, the aforementioned trigeminal nerve, is the largest cranial nerve and has three branches that work together to gather and relay information between the brain and the front areas of the head. Sometimes brainfreezes (or reactions to cold temperatures in the mouth region) will also trigger a sneeze.
Some suggest this is an example of referred pain. Others believe it’s a reaction that allows the brain to stay warm and protected by increasing blood flow to the brain/head and constricting certain vessels in the brain, thus causing a headache.
Brainfreezes don’t tend to last long — only about a minute at most. Studies suggest those already prone and sensitive to headaches and migraines are even more susceptible to brainfreeze. Some suggest warming the palate with a hot food or beverage will remedy the aching sensation.
What I Have Learned
Most of these curious phenomena really didn’t have outright answers. There are many theories, and some of them have been tested to certain degrees, but, for some of these strange and sometimes humorous reactions, there are no hard facts or data to prove why these reactions and reflexes occur.
Many hypotheses are still stammering around waiting to be tested or proven. Although they may know more about biology, medicine, physiology, etc, I suppose their guess is as good as mine! We can all assume whatever we’d like… Perhaps we will never know the real causes of such things!