Ciclograma: a tool for detection of rhythmicities in binary time series

L. DIAMBRA; J.R. LOPES; L. MENNA-BARRETO ; R. RIGOLINO

CHRONOBIOLOGY INTERNATIONAL

TAYLOR & FRANCIS INC

Lugar: USA; Año: 2002 vol. 19 p. 793 - 803

0742-0528

The Fourier spectral analysis of binary time series (or rectangular signals) causes methodological problems, due to the fact that it is based on sinusoidal functions. We propose a new tool for the detection of periodicities in binary time series, focusing on sleep/wake cycles. This methodology is based on a weighted histogram of cycle durations. In this paper, we compare our methodology with the Fourier spectral analysis on the basis of simulated and real binary data sets of various lengths. We also provide an approach to statistical validation of the periodicities determined with our methodology. Furthermore, we analyze the discriminating power of both methods in terms of standard deviation. Our results indicate that the Ciclograma is much more powerful than Fourier analysis when applied on this type of time series.