Tuesday, January 10, 2012

Sleep! Sleep! Sleep!

* this article is extracted from http://sciencepsle.wordpress.com/2010/11/02/sleep/*


How much sleep does an 11 year old or 12 year old need? 9-11 hours is usually recommended. Many Singaporean children fall short by far.

Studies have shown that children with higher IQs usually slept longer. Studies have also shown that children who sleep longer have longer attention span.

Adolescents who suffer sleep deprivation have decreased attentiveness, decreased short-term memory, inconsistent performance and delayed response or reaction time. Some have even attributed it to affecting brain development.

Other studies have shown that people who do not get enough sleep also suffer:

  • Impaired attentiveness (Fallone et al 2001)
  • Impaired ability to retain new memories (Yoo et al 2007a)
  • Impaired immune system (Rogers et al 2001)
  • Greater emotionality (e.g., becoming more upset by disturbing images—Yoo et al 2007b)
  • Increased afternoon and evening stress hormone levels (Copinschi 2005)
  • Increased feelings of hunger (which may lead to overeating—Copinschi 2005)

I am sure this is not new information to most adults. Strangely though, many adults seem to think that their kids can function fine when they sleep at 11 pm and wake up at 6 am. That’s only 7 hours of uninterrupted sleep for a child. Way under what is required.

How does this apply to the primary school child? Well, ever wondered why your child cannot remember things, is restless, easily frustrated, unable to concentrate, careless, not alert. Well, this could be one small part of the answer. Sleep….ZZZzzzzz.

Dr Avi Sadeh of Tel Aviv University conducted a study on fourth and sixth graders. The first group got about half an hour more sleep than usual and the second group got half an hour less sleep than usual. After three nights, the children were tested for their neurobiological function using a test which was highly predictive of both achievement test scores and ability to concentrate in class. The findings showed “the performance gap caused by an hour’s difference in sleep was bigger than the normal gap between a fourth and sixth grader. Which is another way of saying that a slightly sleepy sixth-grader will perform in class like a mere fourth grader. A loss of one hour of sleep is equivalent to [the loss of] two years of cognitive maturation and development.” (Bronson 2007)

A study done on elementary school children my Dr Paul Suratt of the University of Virginia showed that the vocabulary test scores were reduced by seven points due to sleep problems.

At a high school level, Dr Kyla Wahlstrom of the University of Minnesota surveyed over 7000 high school students and found that teenagers who received As averaged 15 minutes more sleep than B students, who on the average had 11 minues more sleep than the C students, while the Cs had ten minutes more sleep than the D students.

A simple search on Wikipedia on Sleep will tell you that sleep is very important for memory processing. “In a study conducted by Turner, Drummond, Salamat, and Brown,[45] working memory was shown to be affected by sleep deprivation. Working memory is important because it keeps information active for further processing and supports higher-level cognitive functions such as decision making, reasoning, and episodic memory.”

Sleep cycles can be divided into NREM (Stages N1-4) and REM. Typically, it occurs in this order of N1, N2, N3, N4 and lastly REM. The proportion of REM sleep increases later in the night and just before natural awakening.

The significance of this information is that Declarative memory (recalling facts) benefits from Slow wave sleep, which occurs in NREM Stages N3 and N4. Procedural memory (sequence, process and routines), however, is processed during REM sleep, which occurs mostly later at night and just before natural awakening. By continually disrupting REM sleep when we awak our children too early, we may infact be affecting their procedural memory.

So before you think that your child is getting by just fine with 7 hours of sleep a night, ask yourself again. Is it good enough for you that you child’s brain development is just scraping through? Is their brain development actually impaired by sleep deprivation?

For an interesting radio broadcast, click on:


Good night. Sleep tight and don’t let the bed bugs bite!

  1. http://www.medicalnewstoday.com/articles/30920.php
  2. http://www.onpointradio.org/2007/10/sleep-deprived-children
  3. Bronson, P. 2007, Oct 7. Snooze or Lose. New York magazine.
  4. Copinschi G. 2005. Metabolic and endocrine effects of sleep deprivation. Essent Psychopharmacol. 6(6): 341-347.
  5. Fallone G, Acebo C, Arnedt JT, Seifer R, and Carskadon MA. 2001. Effects of acute sleep restriction on behavior, sustained attention, and response inhibition in children. Percept Mot Skills 93: 213-229.
  6. Fallone G, Acebo C, Seifer R, Carskadon MA. 2005. Experimental restriction of sleep opportunity in children: Effects on teacher ratings. Sleep 28(12): 1561-1567.
  7. Rogers NL, Szuba MP, Staab JP, Evans DL, and Dinges DF. 2001. Neuroimmunologic aspects of sleep and sleep loss. Semin. Clin. Neuropsychiatry 6(4): 295-307.
  8. Yoo SS, Gujar N, Hu, Jolesz FA, and Walker MP. 2007a. The human emotional brain without sleep—a prefrontal amygdale disconnect. Current Biology 17(20): 877-878.
  9. Yoo SS, Hu PT, Gujar N, Jolesz FA and Walker MP. 2007b. A deficit in the ability to form new human memories without sleep. Nat Neurosci 10(3): 385-392.
  10. www.parentingscience.com

Footnote from me :
1) No wonder I'm losing my memory from lack of sleep
2) My brain's no longer developing
3) Give me better excuses for kids to finish their work faster and go to bed much earlier