biological clock

the mechanism within an organism that controls the periodicity of biological rhythms, including activity rhythms, even in the absence of any external cues. For example, a bird housed in constant light will continue to show patterns of activity and rest with approximately 24-hour rhythms due to the action of the biological clock. A biological clock in mammals is located in the suprachiasmatic nucleus of the hypothalamus. Molecular mechanisms of the circadian rhythm are the same in insects and mammals. Also called internal clock.

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Psychology term of the day

December 3rd 2024

full model

a statistical representation that includes all of the variables of interest, or all of the main parameters (e.g., regression coefficients), among a set of variables. For example, in structural equation modeling, a full model might include estimated regression parameters between a set of independent variables, mediators, and dependent variables. When there are as many parameters estimated in a full model as there are degrees of freedom, it is said to be a saturated model. Also called unrestricted model.