During the 6-month Antarctic winter "night," the 22-man South Pole station is one of the most extreme environments known to man. The authors used this environment as a laboratory to study two discrete behavioral phenomena, "staring" and "drifting." They present the first formal descriptions of these two altered states of consciousness, test etiological hypotheses concerning thyroid and thiamine function, and raise questions about the relationship of these novel behaviors to clinical states of depression. They suggest the possibility of adaptational or pathological analogues of these behaviors in environments less obviously extreme, i.e., mental hospitals, prisons, isolated occupations, and ghettos.Abstract Teaser