Are we out of context?

In the book Evolutionary Medicine and Health: New Perspectives (2008), edited by Wenda Trevathan, E.O. Smith, and James KcKenna, there’s a chapter by Carol Worthman titled After Dark: The Evolutionary Ecology of Human Sleep.

Worthman takes a look at how well people’s current sleep patterns match up with our ecological and evolutionary history — the context in which human sleep evolved. Any species with a long history is affected by the long-term development of the species over time in particular environments. When the environment changes dramatically in a relatively short period of time, there’s a lag as the species’ development catches up, so to speak, adapting to the change in environment. For a while, there’s a mismatch between the species’ current state and its current context.

The motivating question of Worthman’s chapter is are we out of context?

Human sleep

No one actually knows exactly why organisms sleep. Researchers have shown it’s essential; they’ve determined that sleep disruption and deprivation often has negative effects; they’ve mapped out stages of sleep as characterized by patterns of physiological, behavioral, and cognitive activities. Sleep habits are fairly plastic. We have the capacity to have “sleep debts” and make that up later — but if sleep is so important, asks Worthman, why is that possible? What kinds of situations provoke sleep restriction? What roles do stress and stress physiology play in disrupted sleep? And, most importantly, how have our sleep habits and the conditions under which we sleep changed in modern times from the context in which we evolved?

Factors that Worthman addresses include

• - housing, beds, climate control
• - co-sleeping practices
• - material, social, and psychological contexts
• - macrosocial factors such as technology, labor, social structure

How and when a person sleeps is regulated by demands for wakefulness from the circadian system, and demands for rest and slumber. Worthman talks about the evolutionary roots and elements of human sleep ecology. She discusses how sleep settings have tended to be social across societies, even before longhouses and one-room log cabins. We didn’t evolve in an environment where we put oursleves in a room to “lie down and die” for the night. Rather, humans tended to live in groups and sleep in groups, with all manner of activity occurring throughout the night — were fires, noise, other people, conversations, nighttime pests, and more. These were, ecologically speaking, signs of safety and security — signs that it was okay to sleep and let our own vigilance mechanisms relax.

Now think about insomnia for a moment. In some instances, difficulties getting sleep in our current society may be related to how and where we now sleep. If we close ourselves off from noise, fire, other people (essentially, take ourselves out of an environment in which some of the vigilance is taken care of for us), our vigilance mechanisms go off, so to speak, and attention is focused on the kinds of things about which we should be vigilant.

In these kinds of group settings and active-nightlife contexts, was sleep interrupted? Sure. But rather than just losing sleep, people stayed awake for good reasons — useful activities, time and energy demands, threats to physical survival, and social challenges. People have adapted to defer sleep to these kinds of activities. An interesting point — one can recover from lost sleep in far less time than the original deficit. An example Worthman gives is that tem days sleep deprivation can be recovered in one or three eight-hour nights.

A question Worthman asks is just how atypical our sleep patterns are, and whether these patterns are giving us problems we wouldn’t otherwise have.

How much do you sleep?

The biggest thing I got out of her article was this: Bedtimes are fluid. In the US, we seem to have the idea that to sleep properly, we have to be dead to the world for a solid chuck of eight hours. But sleep’s more fluid than that, and sleep isn’t just the time during which you’re dead to the world. We probably underestimate the time that we actually spend sleeping, and we probably make a bigger deal than is actually necessary about getting the recommended eight hours.

Take a look at other cultures — in some, people sleep for five or six hours and night, and maybe have a two-hour nap in the afternoon. Sleep doesn’t have to just be in one chunk. Punctuated sleep is fine. Napping is fine. Some college students seem to have figured this one out already.

Essentially, Worthman argues, we should worry about our sleep a little bit less.

Interested in more of the details?

Worthman’s chapter is definitely worth a read. Pun intended.

Questions vs answers

Recently, I had a discussion with a friend about the key difference between science and engineering.

As a computer engineer, my friend found that the more advanced his coursework got and the more he learned about electronics, circuits, and microprocessors, the better he understood the subjects as a whole.

Which shouldn’t be too surprising. That’s the point of a college engineering degree: learn how stuff works and how to make stuff work.

But me, I find that as I learn more about brains and minds, filled with complex interactions between neurons, glial cells, neurotransmitters, and hormones, the picture gets steadily more complicated. The universe is one big dynamic system, full of chaotic pieces, and I keep finding more questions. The more I learn, the less I know.

That’s the scientist’s perspective on the world: more knowledge means more questions. More astonishment, more confusion.

(This is not a novel pronouncement, merely a recent observation supporting previously suggested differences between the two disciplines.)

A comprehensive Cognitive Science and Computer Science internship resource list

As my undergrad years draw to a close, I’ve compiled a list of internships and related opportunities for students in Cognitive Science and Computer Science. Most programs are also open to students in other engineering and technology fields and are not limited to undergraduate students!

Take a look! Pass along the page to anyone you know who may find it useful. Although deadlines for some summer 2011 programs have passed, many have March or April deadlines, and many of the semester or year-round programs have later deadlines.

Are you familiar with perceptual control theory? If you aren’t, the basic idea is this: People are not rocks. As Philip Runkel puts it,

“Living creatures behave very differently from lifeless things. Unlike a rock, a human does not just sit until something bumps it.”
– Philip Runkel, “Casting Nets and Testing Specimens,” pg 75

The idea is, organisms and agents and people get a bunch of different sensory inputs. They have some internal standards for what they want that set of sensory inputs to be like — some desired state of the world. The difference between how they want the world to be and what the world is actually like drives what they do — what we see as behavior.

The reason this is appealing to me? Perceptual control theory (PCT) says we’re not just input-output machines. Behavior is goal-directed and purposeful.

It’s a useful theory if you want to figure out why people are doing what they do and how to avoid or mediate conflict. Everyone has internal standards that they’re trying to control. As Runkel says,

“[M]ost of us very often act as if we expect other people to behave like rocks. And when we act toward other people as if they were rocks or blankets or typewriters or teacups, we make unending trouble for ourselves. It is true that people do have some features in common with rocks and typewriters. There are, however, important differences between living and nonliving things that most of us overlook time and time again, and to our sorrow.”
– Philip Runkel, “People as Living Things; The Psychology of Perceptual Control,” pg 14

If you want to learn more, I’ve found you a nice list of articles, an informative Less Wrong post a friend linked me to, a comprehensive website, and Google.

And yes, talking about PCT really just was my excuse to share those lovely quotes from Runkel.

Genes: predictor of academic ability?

I found an article today about British researchers who are analyzing the DNA of 4000+ schoolchildren with the goal of finding a relation between the kids’ genes and their academic abilities.

The reason I bring this up is not because the researchers found a gene to explain why you failed your math test, but because the article falls heavily into the “nature vs. nurture” trap. For those of you unfamiliar, nature vs. nurture is the debate over the relative importance of innate qualities built-in from the chromosomes (“nature”), versus personal experiences, environment, and upbringing (“nurture”) in determining individual physical and behavioral differences. Really, it shouldn’t be a debate: organisms’ traits are a result of the interaction of what they start with and where they grow up: nature and nurture. The context in which any organism develops is remarkably important in determining which genes are expressed and how they interact to produce behavior.

Back to the article. There’s one paragraph in particular that gets me:

“Research into height, for example, has picked out 300 genes that affect how tall people will grow, but even these genes can only explain 15% of the total variations in human height. It implies that hundreds more genes must also play a part.”

No, that’s a false choice. What’s implied is that there could be other genes involved, but – and here’s a novel thought – maybe the environment (e.g., nutrition) plays a role? A little bitsy part? Maybe?

A little googling:

In hopes that it was just the reporters who were being deterministic, not the researchers themselves, I set out to find more information.

Robert Plomin of King’s College, London, is the behavioral geneticist cited in the article. He’s currently performing a huge study of British twins. I’ve found several articles stating that he’s a “pioneer in bringing nature and nurture together,” and instead of calling it a “nature vs. nurture” debate, he’s said to have call it (much more appropriately) “nature and nurture.” That’s reassuring. I’d have to read a few of his papers to be certain, but my interim conclusion is that it’s just the reporters.

If you’re interested, I also recently came across a popular article on the gender myth and genetic differences in men and women. It happens to cite Robert Plomin, too.

I collected up all the articles, blog posts, and cool videos about my LARSS summer into one nice, neat page. There’s new material there – I’ve included our project abstract as well as videos of flying quadcopters!

Check it out.

You know you want to.

On the last day of my LARSS internship, NASA EDGE filmed my lab for their Future of Aeronautics episode! It’s currently up on NASA’s main page in the “Podcasts and Vodcasts” section, and it’s available both online and through iTunes. The opening montage has clips of my labmates and I, and the segment about our work starts at 19:18 and lasts three minutes. If you want to see just our segment, it’s on youtube.

I encourage you to take a look!