[Order] Reticular Activating System

[Yvain Wintersong]

Since no one wants to start any more debates, I'm just going to start posting whatever I've been thinking about recently here, in the hopes that someone else finds it interesting. Lately, I've been thinking about the reticular activating system.

Yesterday I read an article claiming that the amount of saliva you produce when tasting lemon juice is closely related to your personality. If you produce a lot of saliva, you're probably an introvert (a quiet person who likes to be alone). If you produce very little saliva, you're probably an extrovert (a sociable person who likes to party).

The key connection is the Reticular Activating System, a net-like arrangement of cells at the center of your brain stem. The Reticular Activating System determines your level of response to stimuli. It's the part of your brain that goes "Hmm..a gnat buzzing around...that's boring, don't worry...hmmm...the constant hum of the fan...that's boring, don't worry...hmmm...a three-headed fire-breathing tiger running towards me...that's bo...WHOA OHMIGOD RUN AWAY!!!"

Introverts have chronically overactive RASes - it's much easier to get the WHOA OHMIGOD response out of them. If an introvert tries to go to a nightclub (and I know this from personal experience), his RAS is going to be thinking "Loud music...WHOA OHMIGOD...bright lights...WHOA OHMIGOD...lots of strange people...WHOA OHMIGOD." He's going to get so stressed and exhausted by the mental overload that he'll be miserable and want to get out. But if he's sitting at home, reading a wiki article about how the reticular activating system works, his RAS will be stimulated just enough to be interested.

Extroverts have chronically underactive RASes. Sit an extrovert at home with a wiki article, and he won't be stimulated at all. He'll be thinking "Meh, this is boring. Nothing happening. I'm tired. Nothing here but this article. Gotta find something to do." Stick him in a nightclub with flashing lights and loud music and strange people, and he'll be stimulated just enough to be interested.

The connection to lemon juice is that it's also a stimulus, the proper response to which is to create enough saliva to digest it properly. Give lemon juice to an extrovert, and his RAS will think "Meh. Just some lemon juice. I'll tell the salivary glands to make a bit of saliva and get rid of it." Give lemon juice to an introvert, and his RAS will think "WHOA OHMIGOD LEMON JUICE, quick, produce as much saliva as possible NOW!"

I like this story because it's a good hit-you-over-the-head-with-it example of how completely complex personality issues are determined by biological factors I'd never have thought of.

Some other things to think about. I produce a lot of saliva (I didn't do the full lemon experiment exactly as laid out, but I winged it) and am very introverted. I also have a very, very hard time studying or relaxing in a room where other people are talking. Further, it takes me a long time to get to sleep at night, usually after a while laying in bed awake. I hypothesize, though I don't have any proof, that these last two are also products of my overactive RAS.

In fact, quick survey time.
1. In your own opinion, are you introverted?
2. Do you have a hard time concentrating in disruptive environments?
3. Does it take you a long time to get to sleep at night?
4. Did you try the lemon juice experiment?

[Neike Taika-Tessaro]

1. In your own opinion, are you introverted?

Depending on whom you ask, introversion and extroversion describe the degree you communicate your feelings to the world, and not whether you like to go to parties or not. I pretty much subscribe to that, and, in that, am hideously extroverted.

Given the more colloquial understanding (and the one used in your post), though, I'm hideously introverted. See, I hate parties - for a variety of reasons, such as people smoking at them (which pretty much instantly ruins my mood, since I get itchy eyes just as fast), people often generally being dumb and confusing this with 'entertaining', and so forth. I've pretty much given up hoping for an interesting party, ever. Not that anyone with half a brain invites me to parties anymore (see above paragraph - I don't try to hide that I'm irritated).

2. Do you have a hard time concentrating in disruptive environments?

It can go both ways. I can focus really well in very active environments if the activity isn't immediately involved with me - as in, if people aren't constantly chatting me up. On the other hand, I typically focus on things when I'm sitting at home, with just a bit of music to keep my mind busy, and spend hours happily with that.

Strip the music away, though, and give me one thing to do, and I'll get uneasy very quickly, because my mind will end up sidetracked... worse yet, if I close my eyes and try to imagine something for longer than, say, five minutes... I CAN'T. My brain automatically veers off on tangents. It's worse than Wikipedia. This, by the way, if by a lesser degree, ruins sex for me.

But I'll also get uneasy and unfocussed if people are chatting me up all the time.

3. Does it take you a long time to get to sleep at night?

Forever.

Edit - especially since my ability to imagine things has deteriorated so much, actually, since it means I can't 'tire' my brain out systematically by entertaining myself with a small bedtime story of my own anymore.

4. Did you try the lemon juice experiment?

No, unfortunately not, since none's at hand. I'd love to know how I 'rate'!

[Andreas the Wise]

1. In your own opinion, are you introverted?
Yes, definitely. Though when I told someone that who knew me through me helping lead a church course, he didn't believe it, and told me I must be one of those introverts that comes across as an extrovert. It's true that with people I know well I'm as talkative and active as any extrovert, but give me new people, or a party ... definitely introverted.
2. Do you have a hard time concentrating in disruptive environments?
Mmm ... couldn't really say. Sorta.
3. Does it take you a long time to get to sleep at night?
Yep.
4. Did you try the lemon juice experiment?
Nope ... just because I couldn't be bothered to. I was highly tempted though ...

[Chrimigules]

Hard to open up, but when you find someone to open up to, you're pretty open?

[Andreas the Wise]

You could say that, yeah ...

[hypatias mom]

1. Are you introverted? I believe so, but my daughter says I must be a shy extrovert because of my need to communicate with people. I don't do well in huge crowds but enjoy the company of a few people at a time, or just one person.

2. Do you have a hard time concentrating in a disruptive environment? It depends on what I am attempting to do. Usually I can function on most levels with other things happening all around me, but when total devotion to detail or communication is essential, outside stimuli often distract from my focus.

3. Does it take you a long time to fall asleep at night? No, usually less than 2 minutes after kissing my husband goodnight.

4. 4. Did you try the lemon juice experiment? Inadvertantly, yes. While I was in the hospital, the kitchen sent up peeled, sliced apples "dipped" in lemon juice. It turned out there was 1/8 inch of lemon juice in the bottom of the fruit cup, which I drank. Yes, I produced quite a bit of saliva (which is happening again as I write this, which I find amusing). Even my memories seem to be introverted.

That was a very interesting study. Thanks.

[Chrimigules]

I sympathize.


1. I'm going to settle for the indecisive "Possibly". I don't really have an opinion either way, though I suppose I'd be more accepting of being classified as introverted than extroverted. It's probably because in my head, my sister is extroverted, and I am completely unlike her in demeanor.

2. It depends on the disruption. Usually, I'll be alright blocking noise. It's definitely a lot easier if I can drown out the unchosen noise with chosen noise (i.e. music on headphones).

3. Usually not really. I'll sometimes play something on my computer to listen to, either music or a documentary or a film or sometimes anime, but when I wake up in the morning, I usually don't remember anything past 10 minutes of eyes-closed.

4. No lemons. The only rough equivalent is the ReaLemon, which my sister uses, but I'm not going to attempt an experiment like this without fresh lemons. SynthLemon = bad.