Wikipedia:Reference desk/Archives/Science/2018 September 9

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September 9

Brainstem removal

I read lots of people had half their brain removed, some right and some left. Yet they are still conscious. I'm almost certainly sure whatever consciousness is, has got to do with the brainstem, and the hemispheres are only for the contents of consciousness. Have there been people with brainstem removed and still alive? — Preceding unsigned comment added by Money is tight (talk • contribs) 00:07, 9 September 2018 (UTC)

• Brainstem death. Abductive (reasoning) 03:07, 9 September 2018 (UTC)

You are wrong. The Brainstem is actually responsible for autonomic (involuntary) functions. The consciousness or intellectual capacity seems to happen in the outer surface, especially with the brains windings that achieve much more surface, developed most in species regarded as very intelligent/conscious, like primates or dolphins. --Kharon (talk) 06:37, 9 September 2018 (UTC)

Presumably you are referring to hemispherectomy. This consists of the removal of one of the cerebral hemispheres, not simply "cutting the brain in half". This is an important distinction. Any significant brainstem trauma generally results in severe disability, coma, or death. --47.146.63.87 (talk) 06:51, 9 September 2018 (UTC)

Damage to the brain stem has so devastating consequences because it is responsible for arousal. Being responsible for autonomic functions does not dismiss its importance to consciousness,

BTW, contrary to Kharon's supposition above. Consciousness implies being physiologically alert, awake, and attentive (that is, what arousal is). Not much can be done without these.Doroletho (talk) 17:57, 9 September 2018 (UTC)

There's a distinction between phenomenal consciousness and "access consciousness". You are phenomenally conscious, for example, when you're dreaming, even though you are not awake or attentive. --Trovatore (talk) 21:29, 9 September 2018 (UTC)

dose testing

In drug trials, as I (mis)understand, only one dosage is typically used, occasionally two. Why not give each subject a different dose, scattered between zero and the safe limit, so as to learn about the shape of the dose-response curve? —Tamfang (talk) 08:43, 9 September 2018 (UTC)

Because that would be useless, see statistics, sample size and statistical power. As everyone is different, you need to know the effects of a dose across a range of subjects to get meaningful results. Something which is sort of what you're talking about and which is sometimes done in phase 1 is an ascending dose regimen, where the subject will get increasingly larger doses as the trial goes on, but multiple subject will still get that. Fgf10 (talk) 09:00, 9 September 2018 (UTC)

Traditionally, multiple doses are tested in Phase 1 clinical trials, but not usually for Phase 3 clinical trials for the reasons Fgf10 has elucidated. There are attempts to change this approach, through Adaptive clinical trials which do investigate dose modification while exploring the therapeutic effect. Klbrain (talk) 23:41, 9 September 2018 (UTC)

People who need 4 hours of sleep.

I'm 1 of those people who need 8 hours of sleep, so I've always been fascinated (and bummed out) about people who only need 4 hours of sleep. I've heard a lot of CEOs and such only need 4 hours of sleep. Now I finally understand how some people can work overtime jobs. Do we know what's the 50th percentile for sleep schedules? Do we know if there's disadvantages to needing more or less hours of sleep? I even wonder about lifespan. An also an evolution question: years ago I read an article that blue-eyes were a mutation, somewhere among White people thousands of years ago, mutated a blue eyed gene. Now I don't suspect we know much about sleep schedules for humans hundreds-thousands of years ago, but now I'm wondering maybe at 1 time, all the humans in the world needed the same hours of sleep, and someone somewhere evolved to differently. Is sleep schedules also genetic? Both my parents need 8 hours of sleep, and they are different races. Same with my sister. And I asked her before if her boyfriend "needs less hours of sleep than her" and she agrees. And then this makes me wonder, men needing less sleep than women is okay, but, what about the other way around, as a relationship question: can a man who needs 8 hours of sleep, be paired with a woman who only needs 4 hours of sleep? Does anyone know of any relationships which have failed because of this? Do we know what % of the population only need 4 hours of sleep, and I've also heard this is predominantly to men, so perhaps the standard deviation for sleep schedules in men is greater than in women. Oh, and should I lastly say, everyone once in a while, I still meet people who 'deny' people who only need 4 hours of sleep, but I don't think this is a dispute among scientists anymore. They're inclined to believe that they'll suffer in the long run. Thanks. 67.175.224.138 (talk) 10:56, 9 September 2018 (UTC).

I think you'll find that people who sleep only 4 hours also mostly take a siesta, or 'power nap' as they call it. Personally I think having a shorter sleep and a siesta is a better idea but unfortunately modern working hours don't normally go well with that. CEOs of course can do their own hours. Dmcq (talk) 11:30, 9 September 2018 (UTC)

One time Tim Russert was interviewing some old-time Yankees players. Phil Rizzuto commented that Joe DiMaggio (who was known for enjoying the night life) used to take a "power nap" in the dugout when the Yanks were at bat. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:47, 9 September 2018 (UTC)

I think one of the most important talents of any CEO is the ability to lie consistently, frequently, and convincingly in order to make himself look good. That's why your wages and pensions get cut to give them ever bigger bucks... Wnt (talk) 13:00, 9 September 2018 (UTC)

Individual need for sleep can indeed be trained to lesser hours. The Sleep cycle is even known to adapt to that. Id agree with Dmcq not trusting the image CEOs draw of themselves tho it is probably part of their job to look like a blueprint of a healthy workoholic. Most are likely Powernapping at work. While everyone thinks they work 14h/day they may actually sleep 4 hours. Why else do they all need a highly payed Secretary to guard their office door?!

But its a very different case in military. Military "Elite" units like Combat divers for example are actually trained to minimize their need for sleep down to 2 hours per day, on missions. Of course that only works for a few weeks at worst, but it works. --Kharon (talk) 22:03, 9 September 2018 (UTC)

Sleeping just 4 hours could explain the crazy behaviour of some CEOs. There's one who makes electric cars whose ill-advised tweeting has been in the news lately, for example. 173.228.123.166 (talk) 23:50, 9 September 2018 (UTC)

1% of the population need 4 hours or less sleep. A few examples:

• Stanley A. McChrystal: "McChrystal is reported to run 7 to 8 miles (11 to 13 km) daily, eat one meal per day, and sleep four hours a night."

• Narendra Modi

• Paul Erdős: "… he only needed three hours of sleep. He’d get up early and write letters, mathematical letters. He’d sleep downstairs. The first time he stayed, the clock was set wrong. It said 7:00, but it was really 4:30 A.M. He thought we should be up working, so he turned on the TV full blast. Later, when he knew me better, he’d come up at some early hour and tap on the bedroom door. ‘Ralph, do you exist?’ The pace was grueling. He’d want to work from 8:00 A.M. until 1:30 A.M. Sure we’d break for short meals but we’d write on napkins and talk math the whole time. He’d stay a week or two and you’d collapse at the end."

As for negative effects in lifespan, one has to take into account here that sleeping time should be subtracted from the lifespan to make a fair comparison. Suppose that sleeping 8 hours a day will lead to a 100 years lifespan. But you'll then have been awake for a mere 66.67 years. If you live more than 80 years with 4 hours of sleep a day, you'll have been awake for more than 66.67 years. Note that Paul Erdős died at age 83. Count Iblis (talk) 00:23, 10 September 2018 (UTC)

It should be noted that anecdotes are not the singular form of data, and that the existence of memorably exceptional individuals does not mean that most people do not suffer from getting less than a certain minimum amount of sleep. This study for example indicated that sleeping less than 6 hours per night leads to a 12% increase in dying before your anticipated lifespan. That people exist who seem to thrive with less sleep does not mean that humanity can thrive on less sleep. The existence of outliers does not represent sound lifestyle advice for the bulk of the population. Or simply put: don't trust what the weirdos can do; they're memorably weird for a reason. Put your trust in what almost everyone else should be doing. --Jayron32 01:33, 10 September 2018 (UTC)

Erdős was also an amphetamine user (mentioned in his wiki biography). 173.228.123.166 (talk) 04:33, 10 September 2018 (UTC)

I happen to thoroughly enjoy my living hours spent sleeping, and strenuously object to the notion that they ought to be subtracted from total time spent living for "fair comparison". 202.155.85.18 (talk) 07:15, 10 September 2018 (UTC)

Not particularly relevant to your main question, but recent genetic studies seem to indicate that European early modern humans (aka Cro Magnon Man) had dark (brown or "black") skin and blue eyes. Iapetus (talk) 09:29, 10 September 2018 (UTC)

If you want to see what happens when a person forces less and less sleep, read about Dick Vermeil's train wreck of a carreer with the Eagles. 216.59.42.36 (talk) 13:23, 11 September 2018 (UTC)