PRESERVATION OF THE FUNCTIONAL ADVANTAGE OF HUMAN TIME STRUCTURE

Upon exposure to sustained and synchronized diurnal activity, most hum an variables exhibit rhythms with a 24 h period. The best-fitting cosi ne curve to the data with a selected period (24 h) may yield parameter s like acrophase (estimated peak time), amplitude, and mesor (rhythm a djusted mean). The sequential array of the rhythms' acrophases constru cts the temporal order. Analyzing 168 different human rhythms revealed a time-dependent distribution with regard to the number of acrophases /h and to the clustering of variables according to function. Rhythms' amplitude/mesor ratios yielded a five modal distribution. The modes oc curred at those clock times where repetitive habitual signals are anti cipated. It is assumed that these specific features evolved to optimiz e the adaptive value of the temporal order.