When Marc Shepanek arrived at McMurdo Station last month, he discovered that his roommate had arranged extra lights all over the room, even leaving some on while he slept.

The abundance of light was actually a direct result of the research that brought Shepanek down here - a study of the causes of physical and mental changes that occur while living in Antarctica. His roommate, who had just completed 15 months on the Ice, was a subject in the study. He was so taken with the light box he got as a participant that he stocked up on as many lights as possible.

Caption: Last November, T3 researcher Marc Shepanek tests the blood pressure of utility technician Dave White, who volunteered for the tests during his summer and winter at McMurdo Station. Shepanek is back on station collecting the results of the medical study. Photo by Kris Kuenning / The Antarctic Sun

Shepanek, chief of aerospace medicine at NASA headquarters in Washington, D.C., is in Antarctica for about a month to wrap up the third and final year of research into the polar T3 syndrome. The syndrome is a thyroid condition that researchers believe is caused when the body adapts to extreme cold.

T3 is a thyroid hormone that acts as a neurotransmitter and also regulates body temperature. In extreme cold, T3 gets used so much to keep the body warm that the brain is left with a less than adequate supply of the hormone. This can cause the "Antarctic stare," common particularly among winter residents, forgetfulness and lack of focus, as well as increased anger, irritation and depression.

The goal of the study is to learn how to combat polar T3 syndrome so that workers in cold places can avoid mental slowness and mood drops.

Shepanek's roommate was Mike Blachut, a refrigeration technician who was a year-long participant in the T3 study. During the 2003-2004 year, the study looked at the potentially positive effect of ingesting a T3 supplement and of using a light box during the day. Fiftythree people participated in McMurdo and 47 at the Pole.

Blachut said he thought the light box worked wonders.

"It just calmed my whole day," he said. He said he got much more irritable and spacier over the winter.

"You can just feel it. If somebody doesn't say ‘hi' to you…it gets magnified. You just build on that," he said before leaving McMurdo last week. He started making extremely detailed "To Do" lists for himself at work, otherwise he said he'd forget what he was doing. He also spent a lot of time looking for tools he'd just put down.

Larry Palinkas, a professor of family and preventative medicine at the University of California at San Diego, heads the T3 study. He said research shows that T3 syndrome is caused primarily by cold, not darkness, though the long Antarctic night may play a supporting role in mood and cognitive decline.

His team has started getting preliminary results from the 2002-2003 season. The results show that T3 levels drop at two main points during the year - during the first month of summer, when people arrive, and again at the beginning of winter. Both are times when the subjects were adapting to lower temperatures than they were used to. But, obviously during the austral summer, subjects were getting much more light than normal.

"That's why we think it has more to do with temperature than light," Palinkas said. To test this theory, some of the study's 2003-2004 participants were given either white or red lights to sit in front of each day, in addition to either a thyroid supplement or a placebo.

The previous year's study focused on the supplements alone. The 2002-2003 participants were given one of three things, either a thyroid supplement or tyrosine, which is a dietary supplement that produces a similar effect as thyroid hormones in the body, or a placebo. Palinkas said the results from the 2002-2003 season indicate the medications had an effect on participants' moods and efficiency in completing computerized tests of cognitive performance. "If you're on an active medication, whether thyroid hormones or thyrosine, your cognitive performance seemed to improve significantly during the winter, but not so much during the summer," he said.

The variation between seasons might be due to the small sample size, which will be countered some when the past year's data is added to the mix. Or, he said, it might be that researchers see a more pronounced effect from the medication in winter because people are battling more pronounced cold at that time.

The fact that the medication appears to be helping is an important discovery, Palinkas said.

"These are fairly low-cost, non-invasive ways of helping people cope," he said. "If we can accomplish that, I think we've done, hopefully, a great service to the U.S. Antarctic Program."

The results also have shown a difference between participants at McMurdo and at the South Pole. McMurdo subjects reported being more depressed during the summer than the winter, while Pole participants said they were more tired in the summer, but more depressed in the winter. Palinkas said this, again, might have to do with small sample size, or it might be that McMurdo is simply a more stressful place to be during the hustle and bustle of the summer months.

Shepanek is interested in these types of community factors that might affect participants' results, but don't show up in blood tests or questionnaires. By living here, he learns which jobs require workers to spend a lot of time outside and which don't. He knows that a dining attendant who lives and works in Building 155 will spend less time outside than a dining attendant living across the station who has to walk to work.

Shepanek specifically requested to live in a louder, more crowded dorm than the relatively cushier ones usually reserved for scientists, so that he could get a sense of how regular dorm life affects residents' quality of life, and thus their moods.

"I wanted to make sure I lived an average life here. A picture is worth a thousand words. Living like everyone else is worth a lot," he said. "If you come down here… you have a better perspective. And having a better perspective makes you a better researcher."

Shepanek is spending about a month between McMurdo and the South Pole, gathering all the study's equipment and data. The subjects had blood samples taken at the beginning and end of each season, and those are being shipped to San Diego for analysis. There are also the results of the subjects' mood questionnaires and the cognitive tests they took on computers. In total, 189 people participated in the study, 100 last year and 89 the year before.

Palinkas said he hopes to have the last round of data ready for analysis by the end of the year so his team can start presenting papers on the polar T3 syndrome in the spring.

Shepanek said NASA is involved in the study because astronauts spend a great deal of time in isolation and, if they go outside their ship or station, in the cold of space. There aren't enough astronauts to form a legitimate scientific study, so the Antarctic workers fill in.

"Since we don't have a lot of astronauts spending time in space, we try to get as much ground analysis as we can," he said. "We really appreciate being here and being able to do this."

NSF-funded projects in this story: Lawrence Palinkas, University of California at San Diego. www.polart3.ucsd.edu