Coordinated daily rhythms are evident in most aspects of our physiology, driven by internal timing systems known as circadian clocks. Our understanding of how biological clocks are built and function has grown exponentially over the past 20 years. With this has come an appreciation that disruption of the clock contributes to the pathophysiology of numerous diseases, from metabolic disease to neurological disorders to cancer. However, it remains to be determined whether it is the disruption of our rhythmic physiology per se (...) (loss of timing itself), or altered functioning of individual clock components that drive pathology. Here, we review the importance of circadian rhythms in terms of how we (and other organisms) relate to the external environment, but also in relation to how internal physiological processes are coordinated and synchronized. These issues are of increasing importance as many aspects of modern life put us in conflict with our internal clockwork. (shrink)

Extending a normal 24 hours day by four hours is unexpectedly highly disruptive to daily rhythms in gene expression in the blood. Using a paradigm in which human subjects were exposed to a 28 hours day, Archer and colleagues show how this sleep‐altering forced desynchrony protocol caused complex disruption to daily rhythms in distinct groups of genes. Such perturbations in the temporal organisation of the blood transcriptome arise quickly, and point to the fragile nature of coordinated genomic activity. Chronic (...) disruption of the daily and circadian rhythms in sleep compromise health and well‐being and this study reveals potential new molecular targets to combat the disruptive effects of shift work and jetlag. (shrink)

Radiation therapy therapists face challenging daily tasks that leave them prone to high attrition and burnout and subsequent deficits in performance. Here, we employed an accelerated alpha-theta neurofeedback protocol that is implementable in a busy medical workplace to test if 12 RTTs could learn the protocol and exhibit behavior and brain performance-related benefits. Following the 3-week protocol, participants showed a decrease in subjective cognitive workload and a decrease in response time during a performance task, as well as a decrease in (...) desynchrony of the alpha electroencephalogram band. Additionally, novel microstate analysis for neurofeedback showed a significant decrease in global field power following neurofeedback. These results suggest that the RTTs successfully learned the protocol and improved in perceived cognitive workload following 3 weeks of neurofeedback. In sum, this study presents promising behavioral improvements as well as brain performance-related evidence of neurophysiological changes following neurofeedback, supporting the feasibility of implementing neurofeedback in a busy workplace and encouraging the further study of neurofeedback as a tool to mitigate burnout. (shrink)

ObjectiveIndividuals with an evening chronotype prefer to sleep later at night, wake up later in the day and perform best later in the day as compared to individuals with morning chronotype. Thus, college students without ADHD symptoms with evening chronotypes show reduced cognitive performance in the morning relative to nighttime. In combination with symptoms presented in attention deficit hyperactivity disorder, we predicted that having evening chronotype renders impairment in attention during the morning, when students require optimal performance, amplifying desynchrony.MethodFour (...) hundred college students were surveyed for evening chronotype and symptoms of ADHD. Of those surveyed, 43 students with evening chronotype performed laboratory attention tasks and were queried about fatigue during morning and evening sessions.ResultsStudents with ADHD symptoms demonstrated a greater decrement in sustained attentional vigilance when abstaining from stimulants and asked to perform cognitive tests at times misaligned with natural circadian rhythms in arousal compared to their non-ADHD counterparts with the same chronotype. While individuals with ADHD symptoms had slower reaction-times during sustained attention tasks in the morning session compared to those without symptoms, there was no significant group difference in working memory performance, even though both groups made more errors in the morning session compared to the evening session.ConclusionThese findings suggest that evening chronotype students with ADHD symptoms are at a greater disadvantage when having to perform sustained attention tasks at times that are not aligned to their circadian rhythm compared to their neuro-typical peers. The implications of this finding may be useful for the provision of disability accommodations to college age students with ADHD when they are expected to perform tasks requiring sustained attention at times misaligned with their circadian rhythms. (shrink)