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The spherical cube model was earlier proposed for explaining interrelationships between scales of multidimensional questionnaires designed for assessing adaptability of the human sleep-wake cycle. The purpose of this report was to use the models predictions for identification of new items associated with yet unassessed sub-traits of the sleep-wake adaptability. The 72-item Sleep-Wake Pattern Assessment Questionnaire (SWPAQ) and an initial 320-item list created for a new inventory were administered to 139 respondents. Results of correlating the responses to these items with scores on six SWPAQ scales were used for classification of items in accord with the nomenclature proposed by the model and for selection of 120 items for the new inventory that allowed the assessment of the majority (more than 24) of the sleep-wake adaptability sub-traits predicted by the model. Some of these newly assessed sub-traits reflect individual variation in the success of biological adaptation to night and shift work. © 2015 Taylor and Francis. Source

Putilov A.A.,Research Institute for Molecular Biology and Biophysics
Chronobiology International

Various characteristics of the sleep-wake cycle can determine the success or failure of individual adjustment to certain temporal conditions of the today’s society. However, it remains to be explored how many such characteristics can be self-assessed and how they are inter-related one to another. The aim of the present report was to apply a three-dimensional structural representation of the sleep-wake adaptability in the form of “rugby cake” (scalene or triaxial ellipsoid) to explain the results of analysis of the pattern of correlations of the responses to the initial 320-item list of a new inventory with scores on the six scales designed for multidimensional self-assessment of the sleep-wake adaptability (Morning and Evening Lateness, Anytime and Nighttime Sleepability, and Anytime and Daytime Wakeability). The results obtained for sample consisting of 149 respondents were confirmed by the results of similar analysis of earlier collected responses of 139 respondents to the same list of 320 items and responses of 1213 respondents to the 72 items of one of the earlier established questionnaire tools. Empirical evidence was provided in support of the model-driven prediction of the possibility to identify items linked to as many as 36 narrow (6 core and 30 mixed) adaptabilities of the sleep-wake cycle. The results enabled the selection of 168 items for self-assessment of all these adaptabilities predicted by the rugby cake model. © 2016 Taylor & Francis Source

Putilov A.A.,Research Institute for Molecular Biology and Biophysics | Munch M.Y.,University of Basel | Munch M.Y.,Ecole Polytechnique Federale de Lausanne | Cajochen C.,University of Basel
Current Aging Science

Age-related disturbances of the sleep-wake cycle can reflect ontogenetic changes in regulatory mechanisms underlying normal and pathological aging, but the exact nature of these changes remains unclear. The present report is the first attempt to apply principal component analysis to the electroencephalographic (EEG) spectrum to examine of whether the observed age-related changes in the objective sleep measures can be linked to the opponent sleep-promoting and wake-promoting processes. The EEG indicators of these processes - scores on the 1st and 2nd principal components of the EEG spectrum, respectively - were compared in 15 older (57-74 years) and 16 younger (20-31 years) healthy volunteers. The scores were calculated for non-REM sleep episodes which occurred during ten 75-min naps scheduled every 150 min throughout a 40-h constant routine protocol. Both, a decrease of the 1st principal component score and an increase of the 2nd principal component score were found to contribute to such most obvious age-related modification of the sleep EEG spectrum as attenuation of EEG slow-wave activity in older people. Therefore, we concluded that the normal aging process can reflect both a weakening of the sleep-promoting process and a strengthening of the wake-promoting process, respectively. Such bidirectional changes in chronoregulatory processes may explain why sleep of older people is characterized by the few profitable and a number of detrimental features (i.e., a better ability to cope with daytime sleepiness and sleep loss vs. difficulty of falling asleep, decreased total nighttime sleep, "lightened" and fragmentized sleep, unwanted early morning awakenings, etc.). © 2013 Bentham Science Publishers. Source

Background and objective: The lack of practical tools for quick and objective testing of sleepiness has become one of the critical barriers to reducing the threats of sleep loss to public health, productivity, and safety. The present analysis aimed to examine whether sleepiness can be measured quickly, directly, objectively, and in absolute terms. Participants and methods: The resting electroencephalogram (EEG) was recorded every other hour during a 43–61-h period of wakefulness in 15 young people. Using the sets of single-Hz powers (1–16 Hz) obtained during the first minute of eyes-closed relaxation, spectral alert (SAC) and drowsy component (SDC) scores were computed. Weights for SAC scoring were derived from differences between spectra for extreme (alert and sleepy) sub-states or distant (first and forth) deprivation phases. Weights for SDC scoring were obtained by correlating the time courses of single-Hz powers with the time course of either subjective or objective sleepiness measures. Results: The scores allowed differentiation of alertness–sleepiness sub-states and occipital scores changed their sign at the boundary between alertness and sleepiness states. Conclusion: SAC and SDC scoring of the EEG signal recorded during the first minute of eyes-closed relaxation can be applied in simple, quick, direct, and objective sleepiness testing. © 2015, Springer-Verlag Berlin Heidelberg. Source

Putilov A.A.,Research Institute for Molecular Biology and Biophysics
Geometry of Individual Variation in Personality and Sleep-Wake Adaptability

Scientific investigation is often aimed on generation and description of a low dimensional simple form that is, however, an accurate representation of the structure of numerous empirically obtained variables. In despite of this aim, some scientific descriptions of real world structures are difficult to visualize due to their dimensional complexity. This new book considers two such structures, the structure of personality lexicon and the structure of adaptive ability of the sleep-wake cycle. © 2011 by Nova Science Publishers, Inc. All rights reserved. Source

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