@article{ref1,
title="Ultradian rhythms in stereotyped and self-injurious behavior",
journal="American journal of mental deficiency",
year="1981",
author="Lewis, M. H. and MacLean, William E. and Johnson, W. L. and Baumeister, A. A.",
volume="85",
number="6",
pages="601-610",
abstract="Institutionalized profoundly mentally retarded persons who exhibited stereotyped motor movements, including self-injurious behavior, were observed continuously in their typical environments for periods of 8 to 14 hours on each of several days. In addition to targeting stereotyped responses, we collected data pertaining to activities, settings, other behavioral states, and social interactions. Spectral and cross-spectral analyses were conducted on data from each daily session. Power spectra indicated a marked ultradian or less than 24-hour rhythm for each subject on each day. Spectral density estimates were thought to reflect the influence of rhythmic changes in the institutional environment and, to a less degree, the influence of an endogenous rest--activity rhythm.<p /><p>Language: en</p>",
language="en",
issn="0002-9351",
doi="",
url="http://dx.doi.org/"
}