Modeling and analysis of non-periodic stimulus on the dynamics of circadian rhythms

Nonperiodic stimuli applied to circadian rhythms to produce phase shifts were modeled, and their transient behavior was studied by dynamic spectrum analysis and frequency demodulation. This type of stimulus produces phase advances and delays that are accompanied by transients. The transients exhibit complicated, nonmonotonic patterns such as those described by previously published data for human biological rhythms following a phase-shift. However, the results suggest that the transient behavior of an oscillator is sufficiently complex to account for the data and that no competing processes need to be involved