Aging and circadian rhythms

In many animal species including humans, numerous processes exhibit 24-hour (h) rhythms. The circadian clock regulates daily rhythms of behavior and physiology such as the sleep-wake cycle (activity/rest), autonomic nervous function, and neuroendocrine function. The mammalian master clock located in the suprachiasmatic nuclei (SCN) of the hypothalamus incorporates environmental information and orchestrates peripheral clocks in other tissues and organs. Various characteristics of daily rhythms undergo age-dependent changes with respect to amplitude, entrained phase, free-running period (τ), and reentrainability. The mechanisms underlying aging of the circadian clock have not been fully understood. This review discusses current findings on age-related changes in daily rhythms of behavior and physiology

Psychophysiological Consistency and Personality

Psychophysiological Consistency and Personality presents an experimental analysis of human individuality as reflected in instantaneous responses to ever-changing situations. Insight into such behavior is considered to be of crucial importance to obtain a complete view of individual functioning in everyday life, and is essential to the growth of knowledge in several areas of psychology such as emotions, information processing, stress and coping, and the etiology and maintenance of psychosomatic and psychoneurotic complaints. The broader context of the study is the area of personality psychology. The perspective is interactional. In daily life, many acts, thoughts, and feelings occur spontaneously. Consequently, more conventional assessment methods such as the questionnaire method, will often not suffice to learn more about instantaneous behavior in complex situations. In this study, films are used as stimulus material, whereas the responses studied are physiological reactions. Methods developed within the context of generalizability theory are used to estimate the amount of behavioral variation arising from multiple sources. In view of the many ambiguities still existing in this area, a large part of the book deals with measurement problems inherent to studies of psychophysiological consistency