Sleep architecture and its relationship to insomnia.

The methods used to obtain and depict sleep data shape our understanding of sleep as a phenomenon. The standard criteria for describing sleep were developed in the late 1960s. These criteria, which were established on the basis of the polysomnographic equipment available at that time, called for the division of sleep into stages according to depth; the visual depiction of these stages led to the now widely accepted concept of "sleep architecture." Although the sleep architecture model remains useful, the technology that provided the model's framework for understanding sleep has been superseded by computer-assisted systems for recording and analyzing sleep that may allow us to acquire data on sleep that were unobtainable with older equipment. Future gathering and depiction of sleep data, regardless of the recording and assessment methods used, should minimize disruption of sleep during study, allow for computerized analysis of sleep parameters, and describe the data from the perspective of the effect that sleep and the problems surrounding it have on daytime functioning.