Resetting the Circadian Clock, continued...

   If Dinges is eager to credit his mentors and colleagues for their roles in his intellectual development, he's doing his best to perform the same function for the generation of scholars who'll come of age in the next century. Over the course of the last three years, Dinges has been able to employ more than 200 undergraduates in his sleep research lab, which is in full-run mode 340 days a year, conducting a variety of studies. Twenty-five undergrads currently work there, most of whom are pre-med, along with two graduate students, a postdoctoral fellow and eight full-time staff -- protocol managers; EEG, hardware and software people; blood-sample technicians and nurses.
Photo by Tommy Leonardi   "The full-time staff and pre- and postdoctoral fellows are vital to the lab's success, but we also give the undergraduate students an enormous amount of responsibility," Dinges says with obvious pride. "We train them in the technical procedures, electrode applications, managing the protocol. There's a whole sequence they have to follow, and they're trained to deal with emergencies."
   Not only are the students exposed to crucial lab time and expected to pull their weight as part of the research team, but Dinges is a huge believer in sharing the expertise that landed his lab so many projects. His students who take on honors thesis projects go to scientific meetings and present their work. "I want them on the podium," he says. "I want them to see how science plays out in a more public forum, among physicians and scientists."
   He expects even more from graduate students. Not only do they work intensively in the lab, they're the ones sent to perform cockpit or truck simulator studies, or sometimes to conduct field studies, where they're monitoring pilots on transpacific flights, for example. But it doesn't end there. "We expect them to go with us to the annual review in front of some of our funding agencies, to present our results to our external scientific-advisory committee," says Dinges. "We make an effort to show they're actively involved and to show the funding agency that we're training the next generation of researchers to deal with these kinds of issues."
   Dinges thinks that if a scientist takes public money, he or she should be able to explain what will be done with it and why it's worth doing. Funding from the National Institutes of Health (NIH) for investigating the consequences of acute and chronic sleep loss has been "our mainstay," says Dinges, but other research support has come from the Department of Defense, "which has had a long-standing interest in ways to maintain the biological limits of human function, as well as NASA and more recently from the Department of Transportation, which is concerned with preventing drowsy driving crashes."

   "I desperately want to know what wakefulness is and what sleep is and what controls them," says Dinges. "What is biology trying to tell us about why brains need to sleep?" Normal sleep is fundamental to achieve normal wakefulness and effortless consciousness. "I am obsessed with consciousness, what people call 'being awake.' Most people know that there are different stages of sleep -- REM and non-REM. But most people think of wakefulness as a single state: 'I'm awake!' We know that is not so."
   Dinges' experiments show that people's ability to integrate information, remember, be alert, is dynamically changing across the day and night. As the pressure for sleep increases due to experimental sleep loss, or a sleep disorder, or night-shift work, the wake state -- as reflected in responses during sustained attention and brain waves -- becomes unstable, drifting in and out of full functioning second by second. When sleep pressure is elevated, our sense of wakefulness as a continuous state is illusory. It is a "story" that Dinges says the brain weaves together by filling in attention and memory gaps with a coherent theme. It's this unstable apparent alertness that hides the actual neurobehaviorial impairments of sleepy patients and subjects. And it is this lack of appreciation for the impairment and likelihood of a sudden sleep attack that makes the excessively sleepy person so dangerous when driving or engaged in other safety-sensitive activities.



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