Yawning
 

So, I woke up today, and yawned. So a question popped into my mind: why do people yawn? I've heard sometimes you yawn because you see others do it, but you know what i mean.. what triggers it? :confused:

I believe it is because the brain needs more oxygen or something to that effect.

according to the latest research the "brain needs more oxygen" theory doesn't hold up. otherwise you would yawn after running a mile or in stuffy rooms.

yawning seems to be a social device signaling the ending or beg. of an activity. as in "let's all finish this boring meeting," or "let's all have a cup of coffee." it's also a way for the body to stretch the facial muscles.

there's very little actually confirmed about yawning.

dt

it is related to many things, boredom, more oxygen, apathy, tiredness and is also contagious.

One of life mysteries...

Post this latest research.

okay if you really want to read it.

Yawning: no effect of 3-5% CO2, 100% O2, and exercise.

Provine RR, Tate BC, Geldmacher LL.

Department of Psychology, University of Maryland Baltimore County, Catonsville 21228.

Using human college-age subjects, the present study tested the commonly cited but previously untested hypothesis that yawning is facilitated by higher than normal levels of CO2 or lower than normal levels of O2 in the blood by comparing the effect on yawning of breathing 100% O2 and gas mixtures with higher than normal levels of CO2 (3 or 5%) with compressed air, the control condition. If yawning is a response to heightened blood CO2, the CO2 mixtures should increase yawning rate and/or duration. If low blood O2 produced yawning, breathing 100% O2 should inhibit yawning. The CO2/O2 hypothesis was rejected because breathing neither pure O2 nor gases high in CO2 had a significant effect on yawning although both increased breathing rate. A second study found that exercise sufficient to double breathing rate had no effect on yawning. The two studies suggest that yawning does not serve a primary respiratory function and that yawning and breathing are triggered by different internal states and are controlled by separate mechanisms.

great, i have had doubts about the "lack of oxygen" thing.....i dont yawn when i smoke or inhale nitrous....while it has no big impact on me, it's still nice to know more about what is really happening.

Really interesting, dtheriault. I know that I yawn a lot in crowds, which I always attributed to an abundance of CO2. Now I'm wondering whether my tiny little brain's socially misfiring or something...

Here's the subsequent question, though: why do animals (some animals, anyway, especially cats) yawn? Same social function?

http://faculty.washington.edu/chudler/yawning.html

I think it that it is related to getting ready to perform an activity. You may yawn when you are bored because your body is getting ready to do something non-boring.

When I was new to weightlifting, I used to yawn quite often after a heavy set. So I always subscribed to the "lack of oxygen" theory. (Now that I've been doing it a _long_ time, that no longer happens.) My point is, brief intense physical activity did seen to bring on yawning in my case. So if the cause isn't lack of oxy, it was something else related to physical activity. And it was something that stopped over time as I became stronger and more used to doing the exercises.

I was told once that yawning dates back to our ancestors when we were still climbing trees. As the social group was spread out over more than one tree, yawning was an effective way to signal the end of the day and time to settle in and sleep. Once the first yawn went out it spread throughtout the whole group.

I think it makes pretty good sense.

Its bloody contagious.

dtheriault: Thanks for the research. Very interesting. Man, I always thought it was the "lack of oxygen" thing too. :confused:

The research that dtheriault posted was done at my school, UMBC, by my professor, Dr. Provine. He also says that yawning is contagious because helps to synch us as a society. Yawning helps us change states. When people go from resting to alertness, we often yawn. We also yawn when we are changing from an alert state to a restful one. In societies, the contagiousness of yawning helps everyone stay in approximately the same state and increase effectiveness of the whole. More info here.

you know what. I yawn when I sing. Does this ever happen to anyone else?

My chorus teacher in middle school proved to the class that when you hold your mouth wide open, it triggers yawning a lot of the time. That's why it's important to not lock your jaw open.

I thought it was to sort out inner ear pressures (by opening the Eustachian tube at the back of your throat) so you can hear a bit more clearly.

Which doubles as a nice explanation of why it's contagious - one person yawns, which sorts him out but changes the air pressure for everyone else (nb geeky joke)

Well, to answer your question as to why you yawn after you woke up...

When you sleep, it goes in cycles, or phases, some phases you are deeper asleep than others. Dreams, however, happen in the deepest phase of sleep, called REM sleep. Or Rapid Eye Movement. As you sleep for longer and longer, the deep phases of your sleep become longer and the light phases of your sleep become shorter.

When you wake up, if it wasn't in one of the one or two lightest phases of sleep, you'll still be tired.

Follow?

Yawning in and of itself, I believe, is a natural reflex you get when your body becomes weary for whatever reason.

I have entertained a slightly different theory most of my life. If we look at the times of occurance and facts:

• seems to be contagious
• when waking up
• when tired
• when not tired
• when interacting with other people
• when alone

We can just about throw out the "when" since they are all countered, and we are left with the contagious bit.

My theory:
Yawning was, and still is largly a sub-concious method of communication.

Back when humans had less developed language and brain functions, we would still need some method to communicate. As humans have a highly developed sub-concious system (heart movements, breathing, walking maybe), it seems reasonable that early humans would require a communicitive method that didn't require higher order brain functions. I'll cut out most of the other support theories and jet right over to a slight defense of why wouldn't we know it?

Well? It seems I tell me where to walk, or can control where to breathe. Why don't I understand when I yawn? I think that the higher order systems don't communicate well with the lower order systems. You can override many functions--you tell yourself when to walk and where to walk, and can hold your breath, but you don't know when your heart is going to beat until it does. Have you ever thought about how you walk? How do you do it? Who knows? Yes, I realize neurons relay to the muscles causing them to expand or more specifically when to contract, but *how* do you know what signaling in the brain to use? This all leads (to me) to the premise that higher functions can't easily communicate with lower functions, vis-versa. Ergo we don't understand why we yawn.

The whole bit about about contagious is helpful. When you speak to others, do they not usually respond? Logic dictates that if a yawn is communication, a responce is usually in order.

I guess I'll leave it at that. Thoughts? Do me a favor and pm me when you reply to my idea. I don't like email notifications...

While I don't have anything terribly important to say, I felt compelled to let you know that yawning is so contagious, I've yawned numerous times while reading these posts about yawning.

On a semi-related note, didn't someone finally determine that hic-ups were a "left over" (I forget the actual term used) involuntary muscle action used to develope lungs while in the womb?

ive heard people yawn in response to others yawns because of a social interaction thing....ie: we feel sympathetic for them....i forget where i heard this

oh and for hiccups...if you pinch a nerve at the back of your neck you can stop the signals being sent from the brain and cease the hiccups....kinda cool

REally, and where did you hear this?

From Wikipedia:

Causes, Concerns and Communications of the Yawn
"What makes us yawn"
Article on "contagiousness" of yawns

I agree with nullitype

I don't know about anyone else, but just reading all these comments about yawning made me yawn, a lot. I'm still yawning as I type this. Maybe it means I'm ready to quit TFP and go do something else... nah.

I remember reading something about the contagious theory that said the need to yawn is displayed in the eyes. If you are looking at someone's eyes when they begin to yawn you will feel the urge to yawn as well.

I always used to yawn when I would go outside into really bright light. It doesn't really happen much anymore. Has anyone else ever experienced anything like that?

I as well have yawned many times reading this... i do believe it is contagious and could very well be subconscious communication... the early homosapien tree theory thing seems interesting, and holds together very well. However this cannot be the sole reason for yawning. People yawn when they are nervous, starting actions, etc to communicate, but they also yawn when they are just tired! After all, may animals yawn... like cats, who arent social animals at all, but rather solemn predators.

And as for why yawning originally happened, i think its either that the brain needs more oxygen, or to equalize the pressure... i yawn alot on airplanes...


and on hiccups: i always thought it was a normal muscle spasm of the diaphragm, much like eye spasms etc

i always thought when tired...it was a boost of oxygen to the brain and to regilate your diaphragm

I have a tendency to yawn when reading outloud. It's extremely annoying, but definately happens. As I type this, I feel the need to yawn. I just yawned and it made my eyes water.

Know what I hate? Sneezing.

Before I could even get down to this post I was yawning like crazy. Weird.

grrr i was fine till i read batman's post :p

I have definately yawned about 8-10 times reading this post... weird

Me too - isn't it just a kind of stretch? I mean, we stretch at similar times as to when we yawn (there goes another one!) Animals yawn, though, I can't seem to imagine browsing animals (cows, horses etc) yawning. I guess they do it though, right?

I also have yawned a ton while reading this thread...

I once read a study that was based on finding out how the "contagious" yawn was "transmitted"...

Basically, the study involved two people in different rooms. They were sound proof, but had a microphone so that one could hear the other person if they were turned on.

They had one person read about yawning on a computer screen while facing a window in between the two rooms, with the other person both watching and listening. An extraordinarily high percentage of the time the other person would yawn as well. They did the same experiment with the microphone off, so the person could see it but not hear it, and it was the same result. They than covered the window, and experience the same result with the subject just hearing the yawn.

Interestingly enough, although I suppose it could be coincidence, when the shut the microphone off as well as covered the window, they continue to yawn at nearly the same time with a complete lack of visual/audio cues. It happened the same as before, with the person reading beginning to yawn and the test subject following suit. However, the percentage of the time that they did it dropped considerably, but was still relatively high considering that they couldn't have any way to see/hear the other person...

Yeah, I'm more apt to believe it's due to a lack/need of oxygen.

I yawn quite a bit after cardio/weight lifting (especially during weight lifting).

Boredom? Tiredness? Sure, but I've yawned when doing things I enjoy while neither tired nor bored... like going up the first hill of a roller coaster or even in the middle of a good movie.

So I dunno.

Hehe, i think hiccups are totally messed up. I used to get them a long time ago, but my older brother always stopped his. When me and him worked together at our family store, and i hiccuped, he'd get really pissed and say "stop it," no explanation of how or why.

Since then, i've somehow figured out how to stop my hiccups. I rarely hiccup more than once, and twice is usually the max. I believe your neck pinching thing is similar, its your way (or someone you know), of telling yourself to stop the hiccup. Like a manual override to the hiccup response.

who knows, maybe we're all just dreaming and hiccups aren't real =P

I heard somewhere that yawning opened up the lungs further. When we're at rest some parts of the lung 'collapse' because of moist walls. Yawning occurs when the body wishes to open up these areas again.

I don't know why we yawn, but just looking at the word "yawn" on this message board made me do it.

Interesting note- Some babboons yawn to bare their canines as a warning to other babboons, or to stupid human anthropologists studying primate behavior :D