PSYB64H3 Study Guide - Final Guide: Jet Lag, Circadian Rhythm, Zeitgeber
9 Dec 2011
School
Department
Course
Professor
Document Summary
The effect of a zeitgeber on the body clock depends on its time of presentation; a zeitgeber can produce a phase advance, phase delay, or no phase shift. This relation between the time of presentation of the zeitgeber and the phase shift produced is called a phase-response curve. The main zeitgebers are the light-dark cycle and the rhythmic secretion of the pineal hormone melatonin (taking place during nocturnal sleep in healthy people): however, exercise exerts a much weaker effect than do other zeitgebers. Even though sleep loss seems to have little effect on muscle strength, maximum muscle performance requires components eg, mood, strategy, and the desire to train to a maximum that are affected by sleep loss. A recorded rhythm can be regarded as a mixture of components because of effects of the body clock (the endogenous component) coupled with effects of the individual"s environment and lifestyle (the exogenous component).
