Approved for public release, distribution is unlimited / This study reports the initial findings of a four-year longitudinal study undertaken to assess the total amount of sleep received by cadets at the United States Military Academy. Specifically, data on the Class of 2007 were collected and analyzed during the freshman year. Survey data were collected (n=1290) on sleep habits prior to the cadets reporting to the Academy. Actigraphy data were collected (n=80) during summer military training and during the Fall academic semester. Survey data were analyzed using two different methods to determine total amount of sleep prior to reporting to the Academy ( x =8.5 hrs, s.d.=1.7 hrs; x =7.76 hrs, s.d.=1.46 hrs). Actigraphy data revealed that cadets received much less nighttime sleep (naps not included) during the Fall academic semester than they reported receiving in the month before CBT (total: x =5.32 hrs, s.d.=35.3 mins; school nights: x =4.86 hrs, s.d.= 37.4 mins; non-school nights: x =6.56 hrs, s.d.=64.4 mins). Using morningness/eveningness chronotypes, owls and non-owls differed significantly along the following dimensions: cadet attrition (z=2.66, p=0.0039), fall term academic quality point average (t=3.92, p<0.001), military program score (t=5.169, p<0.001), and physical program score (t=3.295, p=0.001). Suggestions for additional analysis of existing and subsequent data are proposed. / United States Military Academy, West Point, NY / Ensign, United States Naval Reserve

Os indivíduos diferem em suas preferências quanto ao horário para alocar períodos de sono e de atividade. Essas diferenças inter-individuais se devem, parcialmente, ao relógio biológico que controla funções relacionadas à expressão gênica, secreção hormonal, temperatura corporal, funções cognitivas e comportamentais como o ciclo sono-vigília. O presente estudo cronobiológico teve como objetivo principal avaliar em uma amostra populacional de estudantes universitários da região sul do Brasil, a distribuição dos cronotipos e estudar a relação entre cronotipo e as seguintes variáveis: ponto médio de sono nos dias livres e nos dias de atividade (estudo), bem como avaliar a consistência interna, confiabilidade e concordância entre o Munich Chronotype Questionnaire (MCTQ) e o Questionário de Cronotipo de Horne e Östberg (HO) para identificar cronotipos. Com a análise discriminante dos parâmetros de sono para o cronotipo vespertino destaca-se a importância de se obter preditores mais fáceis para a tipologia vespertina visto que essa característica tem sido associada a alguns riscos de transtornos comportamentais e mentais. Duzentos e quarenta e quatro estudantes universitários (59.0% mulheres), com idade de 17-35 anos, foram analisados através de um estudo transvesal. O Munich ChronoType Questionnaire (MCTQ) foi usado para avaliar os parâmetros de sono nos dias livres e de trabalho (estudo) e o Morningness/Eveningness Questionnaire (MEQ) para avaliar os cronotipos. Os dados foram analisados através da curva ROC (Receiver Operating Characteristic curve) e de uma análise discriminante. As variáveis que apresentaram os mais altos coeficientes discriminantes foram: o ponto médio de sono nos dias livres (0.89) e o início do sono nos dias livres (0.86). Testando os valores de diagnóstico da fase do ponto médio de sono para identificar o tipo vespertino observou-se que a área sob a curva ROC foi de 76%. Este estudo mostrou uma boa sensibilidade e especificidade para identificar o cronotipo vespertino com esses parâmetros de sono. Conclui-se, portanto, que estes parâmetros sejam úteis para identificar o cronotipo vespertino podendo ser usados para propósitos de pesquisa e na prática clínica. / Individuals differ in their preferences to allocate the time periods of sleep and activity. These inter-individual differences are due partly to the biological clock that controls functions related to gene expression, hormone secretion, body temperature, cognitive and behavioral functions such as sleep-wake cycle. This chronobiological study aimed to evaluate a sample of university students in southern Brazil, the distribution of chronotypes and to study the relationship between chronotype and the following variables: mid- sleep on free days and days of activity (study), and to assess the internal consistency, reliability and agreement between the Munich Chronotype Questionnaire (MCTQ) and the Morningness/Eveningness Questionnaire (MEQ) of Horne and Östberg (HO) to identify chronotypes. By discriminant analysis of sleep parameters for the evening chronotype highlights the importance of obtaining easier predictors to the evening typology since such characteristic has been associated with some risks of mental and behavioral disorders.Two hundred and forty four undergraduate students (59.0% women), 17- 35 years old, were assessed in a cross-sectional study. The Munich ChronoType Questionnaire (MCTQ) was used to evaluate sleep parameters on free days and work days and the Morningness/Eveningness Questionnaire (MEQ) to assess chronotypes. The data were analyzed by the Receiver Operating Characteristic (ROC) curve and a discriminant analysis. The variables that presented the highest discriminant coefficients were mid-sleep on free days (0.89) and sleep onset on free days (0.86). Testing the diagnostic values of mid-sleep phase to identify eveningtype it was observed that the area under the ROC curve was 76%. This study showed a good sensitivity and specificity to identify the evening chronotype with these sleep parameters. We conclude that these parameters are useful to identify evening typology and can be used both to research purposes and clinical practice.

Os indivíduos diferem em suas preferências quanto ao horário para alocar períodos de sono e de atividade. Essas diferenças inter-individuais se devem, parcialmente, ao relógio biológico que controla funções relacionadas à expressão gênica, secreção hormonal, temperatura corporal, funções cognitivas e comportamentais como o ciclo sono-vigília. O presente estudo cronobiológico teve como objetivo principal avaliar em uma amostra populacional de estudantes universitários da região sul do Brasil, a distribuição dos cronotipos e estudar a relação entre cronotipo e as seguintes variáveis: ponto médio de sono nos dias livres e nos dias de atividade (estudo), bem como avaliar a consistência interna, confiabilidade e concordância entre o Munich Chronotype Questionnaire (MCTQ) e o Questionário de Cronotipo de Horne e Östberg (HO) para identificar cronotipos. Com a análise discriminante dos parâmetros de sono para o cronotipo vespertino destaca-se a importância de se obter preditores mais fáceis para a tipologia vespertina visto que essa característica tem sido associada a alguns riscos de transtornos comportamentais e mentais. Duzentos e quarenta e quatro estudantes universitários (59.0% mulheres), com idade de 17-35 anos, foram analisados através de um estudo transvesal. O Munich ChronoType Questionnaire (MCTQ) foi usado para avaliar os parâmetros de sono nos dias livres e de trabalho (estudo) e o Morningness/Eveningness Questionnaire (MEQ) para avaliar os cronotipos. Os dados foram analisados através da curva ROC (Receiver Operating Characteristic curve) e de uma análise discriminante. As variáveis que apresentaram os mais altos coeficientes discriminantes foram: o ponto médio de sono nos dias livres (0.89) e o início do sono nos dias livres (0.86). Testando os valores de diagnóstico da fase do ponto médio de sono para identificar o tipo vespertino observou-se que a área sob a curva ROC foi de 76%. Este estudo mostrou uma boa sensibilidade e especificidade para identificar o cronotipo vespertino com esses parâmetros de sono. Conclui-se, portanto, que estes parâmetros sejam úteis para identificar o cronotipo vespertino podendo ser usados para propósitos de pesquisa e na prática clínica. / Individuals differ in their preferences to allocate the time periods of sleep and activity. These inter-individual differences are due partly to the biological clock that controls functions related to gene expression, hormone secretion, body temperature, cognitive and behavioral functions such as sleep-wake cycle. This chronobiological study aimed to evaluate a sample of university students in southern Brazil, the distribution of chronotypes and to study the relationship between chronotype and the following variables: mid- sleep on free days and days of activity (study), and to assess the internal consistency, reliability and agreement between the Munich Chronotype Questionnaire (MCTQ) and the Morningness/Eveningness Questionnaire (MEQ) of Horne and Östberg (HO) to identify chronotypes. By discriminant analysis of sleep parameters for the evening chronotype highlights the importance of obtaining easier predictors to the evening typology since such characteristic has been associated with some risks of mental and behavioral disorders.Two hundred and forty four undergraduate students (59.0% women), 17- 35 years old, were assessed in a cross-sectional study. The Munich ChronoType Questionnaire (MCTQ) was used to evaluate sleep parameters on free days and work days and the Morningness/Eveningness Questionnaire (MEQ) to assess chronotypes. The data were analyzed by the Receiver Operating Characteristic (ROC) curve and a discriminant analysis. The variables that presented the highest discriminant coefficients were mid-sleep on free days (0.89) and sleep onset on free days (0.86). Testing the diagnostic values of mid-sleep phase to identify eveningtype it was observed that the area under the ROC curve was 76%. This study showed a good sensitivity and specificity to identify the evening chronotype with these sleep parameters. We conclude that these parameters are useful to identify evening typology and can be used both to research purposes and clinical practice.

Os indivíduos diferem em suas preferências quanto ao horário para alocar períodos de sono e de atividade. Essas diferenças inter-individuais se devem, parcialmente, ao relógio biológico que controla funções relacionadas à expressão gênica, secreção hormonal, temperatura corporal, funções cognitivas e comportamentais como o ciclo sono-vigília. O presente estudo cronobiológico teve como objetivo principal avaliar em uma amostra populacional de estudantes universitários da região sul do Brasil, a distribuição dos cronotipos e estudar a relação entre cronotipo e as seguintes variáveis: ponto médio de sono nos dias livres e nos dias de atividade (estudo), bem como avaliar a consistência interna, confiabilidade e concordância entre o Munich Chronotype Questionnaire (MCTQ) e o Questionário de Cronotipo de Horne e Östberg (HO) para identificar cronotipos. Com a análise discriminante dos parâmetros de sono para o cronotipo vespertino destaca-se a importância de se obter preditores mais fáceis para a tipologia vespertina visto que essa característica tem sido associada a alguns riscos de transtornos comportamentais e mentais. Duzentos e quarenta e quatro estudantes universitários (59.0% mulheres), com idade de 17-35 anos, foram analisados através de um estudo transvesal. O Munich ChronoType Questionnaire (MCTQ) foi usado para avaliar os parâmetros de sono nos dias livres e de trabalho (estudo) e o Morningness/Eveningness Questionnaire (MEQ) para avaliar os cronotipos. Os dados foram analisados através da curva ROC (Receiver Operating Characteristic curve) e de uma análise discriminante. As variáveis que apresentaram os mais altos coeficientes discriminantes foram: o ponto médio de sono nos dias livres (0.89) e o início do sono nos dias livres (0.86). Testando os valores de diagnóstico da fase do ponto médio de sono para identificar o tipo vespertino observou-se que a área sob a curva ROC foi de 76%. Este estudo mostrou uma boa sensibilidade e especificidade para identificar o cronotipo vespertino com esses parâmetros de sono. Conclui-se, portanto, que estes parâmetros sejam úteis para identificar o cronotipo vespertino podendo ser usados para propósitos de pesquisa e na prática clínica. / Individuals differ in their preferences to allocate the time periods of sleep and activity. These inter-individual differences are due partly to the biological clock that controls functions related to gene expression, hormone secretion, body temperature, cognitive and behavioral functions such as sleep-wake cycle. This chronobiological study aimed to evaluate a sample of university students in southern Brazil, the distribution of chronotypes and to study the relationship between chronotype and the following variables: mid- sleep on free days and days of activity (study), and to assess the internal consistency, reliability and agreement between the Munich Chronotype Questionnaire (MCTQ) and the Morningness/Eveningness Questionnaire (MEQ) of Horne and Östberg (HO) to identify chronotypes. By discriminant analysis of sleep parameters for the evening chronotype highlights the importance of obtaining easier predictors to the evening typology since such characteristic has been associated with some risks of mental and behavioral disorders.Two hundred and forty four undergraduate students (59.0% women), 17- 35 years old, were assessed in a cross-sectional study. The Munich ChronoType Questionnaire (MCTQ) was used to evaluate sleep parameters on free days and work days and the Morningness/Eveningness Questionnaire (MEQ) to assess chronotypes. The data were analyzed by the Receiver Operating Characteristic (ROC) curve and a discriminant analysis. The variables that presented the highest discriminant coefficients were mid-sleep on free days (0.89) and sleep onset on free days (0.86). Testing the diagnostic values of mid-sleep phase to identify eveningtype it was observed that the area under the ROC curve was 76%. This study showed a good sensitivity and specificity to identify the evening chronotype with these sleep parameters. We conclude that these parameters are useful to identify evening typology and can be used both to research purposes and clinical practice.

<p>This study has emerged from a growing interest in students' sleeping habits. During practical training as teachers, we have noticed a discussion of students' sleeping habits, fatigue and student performance at school in relation to their sleeping habits. The purpose of this field survey was to examine students’ sleeping habits and self-perceived performance ability in school in relation to sleeping habits. The material was collected from a questionnaire that was answered by 200 students in 4-6^th grade and 188 students in 1-2th grade in the upper secondary school, this to give an opportunity to see if there were any differences between the different age groups. Differences in gender have also been looked into. The results of the study show that many students, regardless of age or gender, that are sleeping less than 8 hours on school-nights also are tired in school and not able to fully concentrate during the day. The results show some correlation between sleeping habits and how the students feel they are able to perform in school. The results also show that older students sleep less than the younger ones, but a bigger part of the younger students than the older seem to have problems concentrating in school. The results also show a tendency towards differences in sleeping habits between genders, regardless of age, where boys sleep less than girls, but girls have a harder time concentrating in school.</p>

This study has emerged from a growing interest in students' sleeping habits. During practical training as teachers, we have noticed a discussion of students' sleeping habits, fatigue and student performance at school in relation to their sleeping habits. The purpose of this field survey was to examine students’ sleeping habits and self-perceived performance ability in school in relation to sleeping habits. The material was collected from a questionnaire that was answered by 200 students in 4-6th grade and 188 students in 1-2th grade in the upper secondary school, this to give an opportunity to see if there were any differences between the different age groups. Differences in gender have also been looked into. The results of the study show that many students, regardless of age or gender, that are sleeping less than 8 hours on school-nights also are tired in school and not able to fully concentrate during the day. The results show some correlation between sleeping habits and how the students feel they are able to perform in school. The results also show that older students sleep less than the younger ones, but a bigger part of the younger students than the older seem to have problems concentrating in school. The results also show a tendency towards differences in sleeping habits between genders, regardless of age, where boys sleep less than girls, but girls have a harder time concentrating in school.

Zeit ist ein fundamentaler Aspekt menschlichen Verhaltens. Während Untersuchungen bislang meist nur auf einem der drei Hauptaspekte der Zeit: Dauer, Zeitfolge und individuelle zeitliche Orientierung fokussierten, untersucht diese Dissertation Zusammenhänge zwischen der individuellen zeitlichen Orientierung und der Zeitfolge. Zeit ist nicht direkt wahrnehmbar, sondern an kognitive Abstraktionsprozesse gebunden. Diese benötigen kognitive Ressourcen und werden kognitiven Fähigkeiten beeinflusst. Daher wurden Zusammenhänge zwischen individueller zeitlicher Orientierung und allgemeinen kognitiven Fähigkeiten ebenfalls untersucht. Studie 1 analysiert, wie verschiedene Aspekte individueller zeitlicher Orientierung korreliert sind, und diese Korrelationen von Alter und Geschlecht beeinflusst sind. Studien 2 und 3a analysieren Zusammenhänge zwischen individueller zeitlicher Orientierung und der Zeitfolge. Studie 3b untersucht mittels einer geometrischen Analogieanforderung Korrelationen zwischen individueller zeitlicher Orientierung und höheren fluiden Intelligenzleistungen. Befunde zu Zeitperspektive-Chronotyp- Relationen sowie Zeithorizont-Chronotyp-Relationen werden berichtet, ebenso Zusammenhänge zwischen Zeitperspektive, Zeithorizont und der Zeitfolge. Ausgehend von diesen und früheren Befunden wird ein kognitives Modell vorgestellt, welches alle drei Aspekte psychologischer Zeit (Zeitdauer; Zeitfolge; individuelle zeitliche Orientierung) integriert. Ferner werden als Ergebnis der Studien Zusammenhänge zwischen der Zukunftsperspektive und fluider Intelligenz sowie Chronotyp und verbaler Intelligenz berichtet. Verhaltensdaten und psychophysiologische Daten (Pupillendilation) zeigen ferner Zusammenhänge zwischen individueller zeitlicher Orientierung, analogem Denken, exekutiven Funktionen und Konfliktverarbeitung. So scheinen Zukunftsperspektive und Morgentyp eng mit Konfliktverarbeitung verbunden, der Zeithorizont hingegen eng mit inhibierenden Kontrollprozessen. / Time is a fundamental aspect of human experience. Whilst most research investigated major aspects of psychological time - time duration, time succession, individual temporal orientation - in isolation, this dissertation investigates interrelations between individual temporal orientation and time succession. Since psychological time is bound to cognitive abstraction processes that rely on cognitive resources and functions, interrelations between individual temporal orientation and cognitive capacities were also investigated. Study 1 explored how different levels of individuals’ temporal orientation may be interrelated, and how interrelations may be influenced by age and sex. Interrelations between individual temporal orientation and time succession were explored in a task predominantly requiring crystallized intelligence (Study 2) and in a semantic analogy task requiring crystallized and fluid intelligence (Study 3a). Study 3b investigated interrelations between individual temporal orientation and higher-level fluid intelligence measures by applying a geometric analogy task. Interrelations between time perspective and chronotype as well as between chronotype and temporal depth are reported. Further, both future time perspective and temporal depth are interrelated with time succession. A testable global working memory model of time perception integrating all three aspects of psychological time is proposed. Further, interrelations between individual temporal orientation and cognitive capacities are reported. Future time perspective was related to fluid intelligence, chronotype to verbal intelligence. Behavioral as well as pupillary data suggest that individual temporal orientation is related to analogical reasoning, executive functions and goal management. Whereas future time perspective and morningness appear interrelated with conflict detection, temporal depth appears interrelated with inhibitory control.

Abstract There has been an increase in the number of studies investigating the relationship between chronotype, cognitive abilities and academic achievement in different populations. It has been found that an individual’s natural tendency to prefer morning or evening activities is associated with circadian rhythms. The current literature review aims to further review and explore individual differences in chronotype in relation to cognitive abilities and academic achievement and an overview of current evidence on different moderators in chronotypes. The systematic literature review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Study Quality Assessment tool for Observational Cohort and Cross-Sectional studies from the National Institute of Health was employed to assess the quality of the studies included. The systematic literature review identified three studies with 2162 health students from various countries that were eligible for inclusion. Due to the heterogeneity of the studies included, a meta-analysis could not be performed. One of the three studies’ reports was marked with fair quality as some data were missing from their report while the other two were marked to be good quality. The research on individual differences in relation to chronotype, cognitive abilities and academic achievement was not conclusive; however, a positive but weak correlation between cognitive abilities and academic achievement was found when GPA score was considered. Additionally, a significant correlation was identified between learning styles and chronotypes with eveningness obtaining a higher percentage in auditory learning than morningness. On the other hand, morningness obtained higher scores on visual learning styles than eveningness. This correlation was influenced by their chronotype. This systematic review observed differences in outcomes, which could not be compared due to the small sample size, more research into the relationship is required to fill the research gap and determine the effects of these inconsistencies in the relationships / Sammanfattning Det har skett en ökning av antalet studier som undersöker sambandet mellan kronotyp, kognitiva förmågor och akademisk utförande i olika populationer och det har visat att en individs naturliga tendens att föredra morgon eller kvälls aktiviteter är förknippad med dygnsrytmer. Den aktuella litteraturöversikten syftar till att ytterligare granska och undersöka kronotyp i relation till kognitiv förmågor och akademisk prestation samt att ge en översikt över aktuella bevis på olika moderator variabler i kronotyper. Den systematiska litteraturen granskning utfördes efter de riktlinjerna i Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) och Study Quality Assessment tool for Observational Cohort and Cross-Sectional studies from the National Institute of Health användas för att bedöma kvaliteten på de inkluderade studierna. Den systematiska översikten identifierade tre studier med 2162 friska individer med olika nationalitet som mötte inklusionskriterierna. På grund av studiernas heterogentitet kunde en meta-analys inte utföras. En av de tre studierna rapporterar var märkt med rimlig kvalitet eftersom vissa data saknades i artikeln medan de andra två bedömdes ha god validitet. Forskningen om sambandet mellan kronotyp, kognitiva förmågor och akademiska presentation var inte övertygande; dock fann man ett positivt, men svagt samband mellan kognitiva förmågor och academiska prestation när GPA-poäng beaktades. Dessutom identifierades en signifikant korrelation mellan inlärningsstilar och kronotyper, där kvällskänslan fick en högre andel i auditiv inlärning än morgonkänslan. Å andra sidan fick morgonen högre poäng på visuella stilar än kvällskänslan. Denna korrelation påverkades av deras kronotype. Denna systematiska översikten observerade skillnader i resultat som inte kunde jämföras på grund av den lilla urvalsstorlekan, mer forskning om sambandet behövs för att fylla forskningsluckan och fastställa effekterna av dessa inkonsekvenser i relationerna