Pulling an all-nighter does more harm than good

by L&D21 Sep 2016
Remember Dory's short-term memory problems in Finding Dory? That's your brain after an all-nighter, claims a leading academic.

Indeed, binge learning material all night long is not helpful for learning and memory, according to David Earnest, PhD, a professor with the Texas A&M College of Medicine.

"Sleep deprivation's effect on working memory is staggering," said Earnest.

"Your brain loses efficiency with each hour of sleep deprivation."

Earnest said the majority of people need at least seven to eight hours of sleep at night for the body and brain to function normally.

If you miss the recommended amount of sleep, it can result in a sharp decrease in performance for specific learning and memory tasks.

Indeed, quickly trying to cram facts into our brains only uses short-term memory. However, long-term memory is what we need to recall and retain most facts.

"When we try to learn information quickly, we're only enabling short-term memory," Earnest said.

"This memory type extinguishes rapidly. If you don't 're-use' information, it disappears within a period of a few minutes to a few hours.

“Cramming doesn't allow information to assimilate from short-term to long-term memory, which is important for performing well on a project or exam."

Earnest said studying in "small increments", well before a test, is your best chance at performing well.

"It's fruitless to prepare for an exam hours beforehand," he said.

"The optimal study method is to stay on top of things and prepare by studying in small chunks (20 to 30 minutes), multiple times per day, three to four days in advance of the test.

"By going through information numerous times, you're allowing your brain to move those facts to long-term memory for better recall."

Earnest tells his medical students that verbal rehearsal is what moves content from short-term to long-term memory.

"Repeating information, whether out loud or verbalising it in your thoughts, helps spur this process forward," he said.

Earnest also argues that as the day wears on, the brain also becomes wearier. This daily rhythm in cognitive performance is controlled by our body clocks, and performance for learning and memory is higher during the morning than the afternoon and night.

"As the day progresses into the night, the brain's performance significantly decreases," Earnest said.

"So, by studying all night, you're essentially swimming upstream and fighting against your body's natural rhythms. Peak cognitive efficiency occurs much earlier in the day."

Instead of staying up all night, Earnest recommends studying until bedtime and waking up early in the morning before a test to revise the material.

"Sleep rejuvenates by providing an opportunity for the metabolism, body and brain to slow down and recover," he said. "It's crucial that it's not missed."

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