|
Sleep
Deprivation:
Although previous
studies have demonstrated many of the ill effects of total sleep
deprivation, the impact of chronic partial sleep deprivation
(restriction) had not been extensively investigated
even though it is a much more common phenomenon. However, recent
studies indicate that 4 to 6 hours of sleep per night yields
a progressive, cumulative deterioration in neurobehavioral function
including vigilance, neurocognitive performance, and mood. This
reduction in performance is also associated with changes in
cerebral activation during cognitive tasks. Physiologic changes
(insulin resistance and increased sympathetic activation)
appear to occur as well. Both the neurocognitive and
physiologic effects of chronic sleep loss suggest there is optimal
sleep duration and that there is a cost for failing to achieve
it. However, the exact duration of sleep required at different
periods of life remains poorly understood, as do the mechanisms
driving these neural and metabolic processes. |
