If You Sleep After You Study, You'll Remember More—Duh?

Effective Studying in Action (Image from Flickr, by Mrehan)

That sleep improves memory ought to be common sense knowledge, but apparently it is not, even after numerous studies have shown a strong correlation between sleep and memory (see Payne JD (2011) “Learning, memory and sleep in humans.” Sleep Medicine Clinics 6: 15–30 or Marshall L, Born J (2007) “The contribution of sleep to hippocampus-dependent memory consolidation.” Trends Cogn Sci 11: 442–450).

New research published in the Public Library of Science (PLoS) suggests that sleeping right after studying improves a student's ability to remember information. Subjects looked at related or unrelated words pairs either in the morning or evening and then were tested after 30 minutes, 12 hours, or 24 hours. The time of day had no effect on memory. At the 12 hour retest, memory was significantly better after a night of sleep versus a day of wakefulness for unrelated word pairs, but insignificant for related word pairs. However, at the 24 hour retest, the researchers found that memory was superior when sleep occurred right after learning rather than after a day of being awake.

Proms and Frat Parties Seem Like Best Years of Our Lives Due to “Reminiscence Bump”

Life Doesn't Get Any Better? (Image from Flickr, by Speedywithchicken)

Gary Stix published an interesting article on memory on the Scientific American blog on December 16. In his piece, he argues that there are three important truths about autobiographical memories: (1) we can’t remember what happened during the first few years of our lives; (2) we can remember greater details from yesterday than from ten years ago; and (3) the most lucid and lasting memories build up during the reminiscence bump, a period during late adolescence and early adulthood.

Numerous studies have identified this before, including one done by Francis Galton (Darwin’s cousin and an early proponent of eugenics) back in 1879. Stix identifies some recent studies which looked at people’s favorite books and when in their lives they were read. He also pointed to a study of Dutch football fans who, when asked to choose the greatest players of all time, tended to choose players who starred when the test subjects were 17. (The subjects were aged 16-80 and preferred Johan Crujiff, Pele and Diego Maradona).

The reminiscence bump may occur because we are able to form memories more easily during adolescence and because we are starting to develop an adult identity then. This is important for learning and teaching, both for young and for old, and is possibly at the root of the saying “you can’t teach an old dog new tricks.” It may explain why adolescents are so quick to pick up on new technology, while older people often stick with older technologies, even when obsolete. It might also explain why so many people remember their high school and frat party exploits so vividly and adoringly, often calling them the “best years of my life,” trumping marriage, parenthood, homeownership, a successful career or a good night’s sleep.

Then again, what I remember most fondly about my high school and college life (I was proudly never in a frat) was the freedom from serious responsibilities and how carefree I was in those days. I love my wife and my son dearly and they bring me greater daily joy and comfort than I remember experiencing as a youth. I also love teaching. However, I never slept as well as I did in those days, nor have I ever felt so carefree since.