In the 1960s , anthropologists studying the tiv culture in central nigeria found that group members not only practiced segmented sleep , but also used roughly the same terms to describe it .

20世纪60年代，在尼日利亚中部研究蒂夫族（tiv）文化的人类学家发现，蒂夫族人的睡眠是分阶段的，而且每个人对睡眠的描述也都差不多。