title: A fresh look at the use of nonparametric analysis in actimetry.
abstract: Actimetry has been used to estimate the sleep-wake cycle instead of the rest-activity rhythm. Although algorithms for assessing sleep from actimetry data exist, it is useful to analyze the rest-activity rhythm using nonparametric methods. This would then allow rest-activity rhythm stability, fragmentation and amplitude to be quantified. In addition, sleep and wakefulness efficiency can be quantified separately. These variables have been used in studies analyzing the effect of age, diseases and their respective treatments on human circadian rhythmicity. In this study, we carried out a comprehensive analysis of the main results from published articles and devised a functional model of interaction among the several components involved in generating the sleep-wake cycle. The nonparametric variables render it possible to infer the main characteristics of circadian rhythms, such as synchronization with a zeitgeber, and its amplitude and robustness.
authors: Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Brazil; Instituto Federal Sudeste de Minas Gerais, Campus Barbacena, Brazil. Electronic address: bsbgfatec@hotmail.com.
authors: B S B
authors: BS
authors: Gonçalves
authors: Laboratório de Cronobiologia Humana, Departamento de Fisiologia, Universidade Federal do Paraná, Brazil.
authors: Taísa
authors: T
authors: Adamowicz
authors: Laboratório de Cronobiologia Humana, Departamento de Fisiologia, Universidade Federal do Paraná, Brazil.
authors: Fernando Mazzilli
authors: FM
authors: Louzada
authors: Departamento de Saúde Ambiental, Faculdade de Saúde Pública, Universidade de São Paulo, Brazil.
authors: Claudia Roberta
authors: CR
authors: Moreno
authors: Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Brazil.
authors: John Fontenele
authors: JF
authors: Araujo
mesh_terms: D056044:Actigraphy / Q000706:statistics & numerical data*; D002940:Circadian Rhythm / Q000502:physiology; D006801:Humans; D020178:Sleep Disorders, Circadian Rhythm / Q000175:diagnosis / Q000503:physiopathology; D018709:Statistics, Nonparametric
keywords: Amplitude; Circadian; Fragmentation; Functional model; Homeostatic; Rest-activity; Sleep; Synchronization