SLEEP DEVELOPMENT · Development of sleep: Statistical properties and the role of movement-related neural events
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2006-10-01 → 2008-09-30
- EU contribution
- €80,000
- Participants
- 1
- Scheme
- IRG
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Results in brief
Final Activity Report Summary - SLEEP DEVELOPMENT (Development of sleep: Statistical properties and the role of movement-related neural events)
Studies in adult mammals (rats, cats, mice, and humans) have revealed a surprising statistical regularity in the duration of sleep and wake bouts. Wake bout durations exhibit a power-law distribution with nearly identical scaling exponent across these four species, whereas sleep bout durations exhibit an exponential distribution with a characteristic time scale. These data suggest that bout distributions may offer novel metrics to make comparisons of human and animal sleep-wake data. Studies in rodents have found a developmental trajectory in which sleep bout durations are exponentially distributed at all ages examined, with a developmentally increasing characteristic timescale reflecting sleep consolidation. Wake bouts, on the other hand, exhibit exponential distributions early in ontogeny with a clear power-law emerging only at the older ages. In order to test the generalisability of these findings, we examined the distributions of sleep and wake bouts during the night in a healthy human sample - from premature infants to 70-year-olds. We find that sleep bout durations exhibit exponential distributions at all ages tested, except for the youngest (premature infants). Moreover, sleep bouts elongate over the first years. Wake bouts shorten during this time, but elongate again with increasing age. Most notably, wake bouts exhibit a power-law distribution only during a restricted time window during adulthood. The current findings, therefore, indicate that the developmental trajectory of human sleep-wake cycles does not map well onto those of rodents. Further development of this method of characterising sleep-wake cycles using bout distribution holds promise for classifying properties of sleep and its disorders, and for tracking developmental milestones across the human life-span.
Data: CORDIS, © European Union
Project objective
Primary aim: Even though normal sleep seems to most to be uninterrupted, it consists of discrete bouts of sleep and wake. Recently, it has been shown, in humans, that the duration of these bouts, historically seen as a random or pathological disruptions, follow a clear statistical pattern.In adults the wake bouts durations exhibit a power-law distribution whereas the sleep bouts exhibit an exponential distribution; moreover, the distribution of wake bouts does not vary between species, whereas, sleep bout durations, while always following an exponential distribution, do so with a characteristic time scale changing in relation with body mass and metabolic rate.Developmentally, (thus far only addressed in rats) the power-law distribution of wake bouts emerge s only gradually and the scale of sleep bout durations changes relative to the age of the organism. Here it is proposed to provide a full description of how these statistical patterns change across the lifespan in humans with the intent to create a novel, behavioural state-stability based, method of classifying sleep and its disorders. Secondary aim: It is known that movements in general correlate well with development; however, mechanisms governing this are unclear.Recent findings in developmental sleep research has revealed patterns of movement-related neural events occurring in sleep that provide conditions conducive to activity-dependent development. Here it is proposed to, first, describe the human homologue of these movement-related neural events, and, second, to correlate their incidence with measures of development.
Original text from CORDIS.
Participants
- REYKJAVIK UNIVERSITY · REYKJAVIKCoordinatorCity levelIceland
Links
Data: CORDIS, © European Union