Researchers Paula Alhola and Paivi Polo-Kantola examined the effects of sleep deprivation on cognitive thinking. First they differentiated between chronic partial and acute total sleep deprivation or SD. Then they compared the studies of chronic partial sleep deprivation versus acute total sleep deprivation.
On average, people need about 7.5 to 8 hours of sleep per night. However, the actual number varies by individual. The 2 sleep processes that a person goes through are called homeostatic process S and Circadian process C. Homeostatic processes regulate wakefulness while circadian processes regulate the onset and offset of sleep. Sleep cycles are regulated by the interaction of the 2 processes.
Sleep deprivation causes memory loss, high blood pressure, insulin resistance, impaired immune response, and adverse effects on mood. The researchers examined the full effect by using sleep deprivation as a research design. In the study, subjects were kept awake for 24-72 hours to examine acute total sleep deprivation, while the other subjects' sleep was restricted for several consecutive nights. Variables studied were short-term memory, long-term memory, visual, verbal, and auditory functions. This study also accounted for the fact that some individuals need more sleep than others.
The researchers found that the effects of partial SD are not as well known as acute SD. Sleep deprivation studies need to have a larger sample as well. Results of their study found that aging does prolong wakefulness while impairing cognitive performance and that women handle prolonged wakefulness better than men mentally, but they recover slower physiologically. However, the effects on younger men and women is still unclear. Alhola and Kantola recommend a more thorough study be made.
Critique: Alhola and Kantola are correct in their recommendation that more thorough studies be made. With the emphasis on cognitive performance in the modern work force, it is essential that we understand the full impact of sleep deprivation on our brains. However, while they point out previous studies and criteria, they do not give a methodology of their own; merely stating that methodological issues be more thoroughly examined.
Citation: Alhola, Paula and Polo-Kantola, Paivi. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2656292/.