Jacqueline Kory-Westlund

The longest Monday of my life

I recently returned to the US from Australia. The 14-hour flight took me from Monday morning in Sydney to Monday morning, again, in L.A. Crossing the date line messed up my sense of time enough without the added bonus of thinking I should be heading to bed just as the sun began to climb into the California sky.

You may be familiar with the concept: Jet lag. The catch-all name for circadian misalignment, the disruption of sleep cycles and circadian rhythms. If you've had the pleasure of crossing time zones in a jet plane, whether it was a mere three-hour hop from one coast of the US to the other or a trip to another continent, chances are, you've experienced some amount of jet lag.

The pathophysiology of jet lag

Normally, two systems--the homeostatic system and the circadian system--work together to produce a 24-hour sleep cycle. During the day, the homeostatic system slowly accumulates a 'sleep drive,' a desire to sleep that increases as a function of time spent awake. The circadian system generates an alerting signal in opposition to this sleep drive, which, during the day, keeps a person from feeling increasingly sleepy. An hour or two before bedtime, this signal subsides, and s/he realizes it's time to hit the pillow. The sleep drive dissipates as a person sleeps and by morning (assuming a full night's rest and possibly some coffee), s/he will be feeling alert and ready to go again.

Robert Sack wrote a delightful paper [PDF] on jet lag, by the way, which is where I'm getting much of my information.

So we've got a nice cycle of sleep. Jet lag is what happens when the homeostatic and circadian processes are misaligned. For example, the circadian system may signal a person to be alert when it's not actually morning, or may be reduced during daytime hours, causing daytime sleepiness because the homeostatic sleep drive is no longer cancelled out.

But I don't want to be sleepy!

How do you beat jet lag? Robert Sack lists three primary approaches:

1. Reset the body clock
2. Prescribed sleep scheduling
3. Medication to counteract daytime sleepiness or insomnia

Let's start with the first one, as it turns out to be the most complicated.

Resetting the body clock

The two most effective ways to reset the body clock are 1) through bright light exposure, and 2) timed melatonin administration. (But see the end of this post: fasting can also reset the body clock.)

Light is one of the most important cues about time of day and has the greatest effect on circadian timing (much smaller effects are seen from regular activities and meals, for example). Studies have shown that without light cues, totally blind people tend to have free-running circadian rhythms with an average period of 24.5 hours, instead of the usual 24. If a person is exposed to bright light early in the day, the person's internal clock is reset to an earlier time; if exposure is instead in the evening, the internal clock is reset to a later time. Brighter light has more of an effect (such as the sun, at 3000 to 10,000 lux), though lower intensities (e.g., 100-550 lux) can produce changes.

Artificial light sources can be used to supplement daylight, to help reset a person's internal clock to the correct new time zone when traveling. Alternatively, a person could wear very dark glasses, as light avoidance could help minimize the problems of light exposure at the wrong time of day or night.

Resetting the body clock, Part 2: Melatonin

Melatonin is a hormone that has been linked to the regulation of circadian rhythms and sleep cycles [PDF]. Melatonin is secreted by the pineal gland at night; secretion is suppressed by light exposure, and as such, the hormone can be thought of as a "darkness signal." If doses of melatonin are administered in the morning, circadian rhythms will be shifted later; evening doses shift rhythms earlier. Timing of the doses is more important than amount per dose, though it remains to be seen what the optimal dose and optimal time of administration is--trials have been done with doses from 0.5 to 10mg, at times ranging from three days before departure to five days after arrival in the new time zone.

If doses of melatonin are combined with light exposure, the results are what you might expect: synergistic if both are administered to produce a time shift in the same direction (both earlier or both later); antagonistic otherwise.

Sleep, wake, sleep, wake

The second way to beat jet lag: Sleep at weird times. Slowly adjust your sleep schedule to match that of your destination, or keep your home sleep schedule for a while after you arrive. The problem with this is that your sleep-wake schedule won't match up with that of the people around you, and if you need to be awake for breakfast at 7am or for a meeting in the afternoon, your sleep schedule may interfere. Use this method at your own risk.

Drugs for everything

Lastly, we have sleep medicines. As you might guess, hypnotic medications combat insomnia and stimulants fight off daytime sleepiness pretty well, because by definition, that's what they do. Both benzodiazepine and non-benzodiazepine drugs have been shown to be effective in the first case; for the latter, the most common solution is to consume more coffee [PDF]. This works! In the study linked, subjects were treated with slow-release caffeine or with melatonin prior to a long eastward flight; the caffeine subjects were less sleepy than either melatonin or placebo. Granted, caffeine subjects also took longer to fall asleep later and awoke more frequently, but that may be a risk you have to take.

Lagging behind

Light, melatonin, drugs, strange sleep schedules. Of course, the only solution that will always work is time. The homeostatic and circadian processes need to realign, and while the aforementioned ways of beating jet lag can fast track the process, it still takes time.

UPDATE: I was alerted by a friend of the existence further research of which I was unaware: Another way to reset your sleep-wake cycle is to stop eating. If you fast for about 12 to 16 hours, your body clock will reset, with whatever time you break your fast as morning. The Fuller, Lu, & Saper paper [PDF], published in Science, discusses the mechanism, though a more recent paper argues that the Fuller et al. results are inconclusive.

Snapshot: Classroom

Tap tap tap. That's your pencil hitting the edge of your desk, one rhythmic note at a time. The wood of the pencil has a little indent now from all the tapping (unless you use a mechanical pencil), but at least you're still awake. The kid next to you has been slumped over his notebook for the past half hour. You're pretty sure he's snoring. He has every reason to be, though; the professor has a fantastically monotone voice. Bullet point after bullet point, slide after slide. It's not like you have to pay attention, either--everything the professor is saying is in the lecture notes handed out at the start of class. But you feel obligated to try to stay awake.

Death by Power Point

Is this at all familiar? Most of us, at some point or another, have experienced the ultimate Boring Lecture: A droning, not-quite-loud-enough voice, reading sentences one by one off a set of elaborate PowerPoint slides. The slides look pretty, sure, but fancy formatting can't overcome the serious lack of anything remotely engaging.

Fortunately, most lecturers aren't that bad. But as my friend Carolyn points out, a lot of professors still rely too heavily on PowerPoint. The primary instruction, she says, needs to come from the professors, not from the text slopped across their slides.

And it's true. A lecture is a performance, and Hubert Knoblauch's (2008) analysis of PowerPoint presentations suggests that the use of PowerPoint serves to amplify the performance aspect. Slides should complement rather than replace the presenter's speech. They should be used to emphasize points and help explain difficult concepts with diagrams and photos; after all, a separate sheet of lecture notes with all the text of the bullet points can be handed out later. This may sound obvious, but in practice, most of us conform to convention of cluttering up our slides with too many words and too much visual noise.

Keep it simple, stupid

How do we fix this problem and avoid death by PowerPoint? Garr Reynolds recommends a highly minimalist approach (he's got a handout[pdf] summarizing his suggestions). Instead of lists and summaries, put just a few key words boldly in the middle of the slide. Use large images and diagrams. Turn off the projector entirely when you happen to digress from the slides. Remove excess logos and irrelevant graphics--they're just visual noise that detract from your message.

It may take some effort to get the hang of the minimalist presentation (I certainly haven't gotten it down, though I try), and it will certainly take some guts to be the nonconformist who doesn't use bullet points. One of my professors at the University of Sydney told a story about a student who went minimalist and was marked down as a result: It wasn't a proper presentation! (The audience, however, said it was one of the best presentations they had seen in a long time.)

A place for everything

That said, bullet points occasionally have their place: e.g., when the goal is to memorize facts (Kinchin & Cabot, 2007). But if the aim is to make links between concepts and gain a deeper understanding of the subject, other methods of presenting information may fare better. I'll open up the floor. What tips and tricks do you keep up your sleeve for making a PowerPoint engaging? Do you adhere to minimalism? Obviously, it's not all about the slides--it's also about delivery. Feel free to share thoughts on that, too.

References:

Knoblauch, H. (2008). The Performance of Knowledge: Pointing and Knowledge in Powerpoint Presentations. Cultural Sociology, 2(75):75-97. [PDF]

Kinchin, I., & Cabot, L. (2007). Using concept mapping principles in PowerPoint. Eur J Dent Educ, 11: 194-199. [PDF].

"I got these pictures off the Internet."

This is not a sentence that should ever be uttered when one is giving a presentation, yet last week, a fellow student said those exact words.

"The Internet" is not a reference.

Chapters of books, articles in journals, and individual web pages can be references. The Internet, instead, is like a library: A place to find references. You don't cite your library in presentations.

Perhaps some of the confusion arises because all the content on the Internet is accessed through the same program (your web browser of choice). Because it is all seen in the same window on your monitor screen, it must all originate in the same place, right? Intelligent people know better, yet it is still easy to fall into the trap of assuming that images in particular and digital media in general belong not to one author, but to the vast, amorphous sea of information floating around cyberspace. If it shows up in a Google search, it's free for the taking, right?

I'm not going to lecture you on copyright laws or on how to properly cite images. But for the curious, here is a long and detailed explanation of copyright and digital images. If that's too long, pop a couple words such as "digital images" and "copyright" into Google and I'm sure you'll find a summary. I'll also recommend Chris Chesher's article on blogs and the crisis of authorship, a related but not identical topic.

References:

The Internet. Accessed November 3, 2009.