title: Laboratory investigation of "biorhythms".
abstract: Three subjects were tested on an information processing task on a daily basis for a period of 70 d. Performance measurement included reaction time, movement time, and information processing rate. The data set obtained was subjected to Fast Fourier Transforms (FFT) in an attempt to identify periodicities in performance. Twelve significant harmonics were identified and nine were found to be within 1 d of at least one of the cycles hypothesized by the theory of "biorhythms." The probability of this occurring by chance is remote (p less than 0.05), assuming a uniform distribution of significant amplitude. The results were interpreted as suggesting the possibility of a biorhythmic influence in the performance of the task.
mesh_terms: D000328:Adult; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D009068:Movement; D010507:Periodicity; D011930:Reaction Time / Q000502:physiology; D013647:Task Performance and Analysis