light patterns. The sun never sets from late
October to mid-February, while there is no
sunlight at all during the Antarctic winter
from late April to mid-August.
Previous studies have shown that in
Antarctica, people go to sleep later in the
day during the dark winter months. Work
by endocrinologist Josephine Arendt in
the 1980s identified a corresponding delay
in the rise and fall of blood levels of mel-
atonin—a hormone that helps regulate
sleep onset—during the winter among
personnel living in Halley, a British Ant-
arctic Station (J Physiol, 377:68P, 1986).
To learn more about how this extreme
environment could affect sleep patterns,
Vigo gathered support from several insti-
tutions—including the Argentine Joint
Antarctic Command, the National Uni-
versity of Quilmes, and the Argentine
Antarctic Institute—to launch a scientific
endeavor to study human behavior there.
The project, which Vigo supervises from
Buenos Aires, has been running continu-ously since 2014 in the Belgrano II Base,
located in Coats Land approximately
1,300 km from the South Pole.
Accompanying the Argentine army
personnel who made up the first study
participants was military doctor Agustín
Folgueira. In early 2014, as he made the
final leg of the journey by helicopter—
ships can’t dock due to the presence of
a massive ice shelf—the station looked
“like a black speck in an enormous mass
of ice,” Folgueira recalls in Spanish. He
remembers suddenly realizing that,
for a year, there would be no chance of
going back.
As part of his PhD thesis in Vigo’s lab,
Folgueira was responsible for collectingdata on the physiology and behavior of his
companions during the first year of the
research project. To monitor their sleep
patterns, 13 men used a wrist accelero-
meter for seven consecutive days every
two months, from March to November- These devices collect information
related to arm movements, Vigo explains.
“Naturally, when we’re awake we tend to
make a lot of movements, and when we’re
asleep we tend not to—we move very lit-
tle or not at all,” he says. Measuring those
movements “allows us to detect periods of
activity and sleep.”
Analyzing the first round of data
from their project, the team reported
earlier this year that the participants
showed the same delay in sleep onset
in darker months that had previously
been observed in other research person-
nel in Antarctica. They also experienced
a reduction in their nighttime slumber
during winter, sleeping approximately
one hour less than they had in March.
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Antarctica is an amazing
opportunity, because it’s
almost like a living lab.
—Siobhan Banks,
University of South Australia