Biorhythm

Abstract: Since thediscovery ofan approximate 90-min oscilla- tioninrapid eye movement(REM)or dreamsleep, muchinterest hasbeenexpressed inthephysiological andbehavioral parameters associated withthisphenomenon. Oneoftheoften stated theories isthatthis90-minrhythmisan end.ogenous biorhythm present throughout the24-hday,perhaps representing a rest-activity cycle ofthenervoussystem. Anapproximate 90-min biorhyfhm inresting humanheart rateisassessed anddescribed usingthetechniques of periodogram analysis andcomplex demodulation. Thetechniques employed foundevidence forthis rhythm inallsubjects; in- addition, theamplitude ofthe90-min ultradian rhythmseemedtobemodu- lated bya circadian(24-h) rhythin. However, themodulating circa- dianrhythm was notusually phaselocked tothecircadian rhythm fixed bythewaking/sleeping cycle ofeachsubject.

Abstract: Biorhythm theory which became popular with the general public in the late 1960s held that three different biorhythm cycles influenced three different general aspects of human behavior. There was a 23-day cycle which influenced physical aspects of behavior. A 28-day cycle influenced emotions and a 33-day cycle influenced intellectual functions. Further, according to the theory, these three cycles started at birth and progressed, sinusoidally, throughout life varying not a bit with environmental or physiological factors. This paper reviews 134 studies of biorhythm theory, both published and unpublished. 35 of those reported some support for biorhythm theory. Careful examination of these studies identified methodological and statistical errors that account for the claimed findings supporting the theory. Another 99 studies, covering many different variables, yielded no support. The conclusion is that biorhythm theory is not valid.

Abstract: Evidence of a periodic biorhythm is retained in tooth enamel in the form of Retzius lines. The periodicity of Retzius lines (RP) correlates with body mass and the scheduling of life history events when compared between some mammalian species. The correlation has led to the development of the inter-specific Havers-Halberg oscillation (HHO) hypothesis, which holds great potential for studying aspects of a fossil species biology from teeth. Yet, our understanding of if, or how, the HHO relates to human skeletal growth is limited. The goal here is to explore associations between the biorhythm and two hard tissues that form at different times during human ontogeny, within the context of the HHO. First, we investigate the relationship of RP to permanent molar enamel thickness and the underlying daily rate that ameloblasts secrete enamel during childhood. Following this, we develop preliminary research conducted on small samples of adult human bone by testing associations between RP, adult femoral length (as a proxy for attained adult stature) and cortical osteocyte lacunae density (as a proxy for the rate of osteocyte proliferation). Results reveal RP is positively correlated with enamel thickness, negatively correlated with femoral length, but weakly associated with the rate of enamel secretion and osteocyte proliferation. These new data imply that a slower biorhythm predicts thicker enamel for children but shorter stature for adults. Our results develop the intra-specific HHO hypothesis suggesting that there is a common underlying systemic biorhythm that has a role in the final products of human enamel and bone growth.

Abstract: All physiologic functions demonstrate cyclic activity. Infant development includes maturation of biorhythms. Two basic changes in biorhythm include establishment of circadian rhythm and day-night pattern. Biorhythms are driven by internal pacemakers yet are highly susceptible to environmental influences. Sleep-wake pattern and body temperature rhythm are two examples of infant biorhythms that demonstrate significant change with development. Biorhythm is the scientific basis for interventions (such as cycled lighting, feeding schedule, and caregiving pattern) aimed at improving the fit between infant and the environment.