Circadian clocks evolved under conditions of environmental variation, primarily alternating light dark cycles, to enable organisms to anticipate daily environmental events and coordinate metabolic, physiological, and behavioral activities. However, modern lifestyle and advances in technology have increased the percentage of individuals working in…

Circadian variations have been found in cognitive processes, such as attention, working memory, and executive functions, which may explain oscillations in the performance of many tasks. These cognitive processes improve during the day and decrease during the night and early hours of the morning. Sleep deprivation further decreases these cognitive…

The literature indicates that glucose deprivation, dehydration, decreased sleep quality and quantity, and mood changes, independently and adversely can influence cognitive functions and therefore learning. The Ramadan fast is an annual religious act undertaken by Muslims where individuals refrain from consuming food and fluid during daylight…

Objective: Agomelatine is a relatively new antidepressant, with affinities to MT1 and MT2 (responsible for the circadian rhythm) as well as to 5-HT2C receptors. Since antidepressants have demonstrated some benefit in the treatment of ADH and because of the fact, that ADHD is often associated with sleep disorders, we assumed, that it might be a…

The authors have integrated the major findings on the sleep-wake cycle and its performance correlates in adolescents. Basic research shows that lack of synchronicity between early school start times and the circadian rhythm of adolescents (and the sleep debt accumulated as a result) involves several cognitive correlates that may harm the academic…

The circadian rhythm functioning and sleep patterns of 10 adults with Asperger syndrome were investigated using actigraphy. When compared with data from neurotypical adults, both statistical and clinically significant differences were found between the two groups, with the adults with Asperger syndrome showing marked abnormalities in both the…

Neurobiological models propose an evolutionary, vertical-integrative perspective on emotion and behavior regulation, which postulates that regulatory functions are processed along three core brain systems: the brainstem, limbic, and cortical systems. To date, few developmental studies applied these models to research on prenatal and perinatal…

Introduction: In this paper we investigate how students' class grades are affected by individual differences in circadian rhythm, class time-of-day and class difficulty. Method: Using a sample of university students, we assessed morningness and eveningness personality type, and then obtained students recalled classes as well as their…

Educators around the nation are considering pushing high school starting times back until later in the morning, based on evidence suggesting that amount of sleep and circadian rhythms play a part in adolescents' academic performance. While research confirms that adolescents do not get enough sleep and that insufficient sleep can negatively…

A school transition project examined effects on sleep and circadian rhythms in a group of 25 youngsters shifting from an 8:25 a.m. junior high school starting time to a 7:20 a.m. high school starting time. The average amount of sleep on school nights fell substantially for 9th and 10th graders, and was below the amount required for normal…

Fragile X syndrome is the most common heritable form of mental retardation caused by loss-of-function mutations in the "FMR1" gene. The "FMR1" gene encodes an RNA-binding protein that associates with translating ribosomes and acts as a negative translational regulator. Recent work in "Drosophila melanogaster" has shown that the fly homolog of…