J. George
According to the Center for Disease Control and Prevention, 1/3 of adults “are not getting enough sleep on a regular basis.” Though the reasons for this missed sleep vary, the effects of sleep deprivation are similar. Despite missed sleep’s negative impact on memory, many students choose to pull all-nighters rather than getting a good night of sleep before a test. Dominique Gosselin et al. conducted a study to determine the effects of sleep deprivation on semantic memory. Semantic memory is associated with common knowledge, such as knowing that grass is green, and is sometimes referred to as “permanent memory.” Sleep deprivation reduced the test subjects’ semantic memory.
In the study, 12 college students were tested with 7-8 hours of sleep and again after a night of total sleep deprivation. During the test, the students were given a pair of words, some that were associated and some that were not, and the test subjects had 1.2 seconds to press the “associated” or “not” button. Different word pairs were used for the normal sleep and total sleep deprived groups (abbreviated as “NS” and “TSD”). The table compares the performance of the 12 individuals with NS and TSD. Total sleep deprivation decreased the subjects’ ability to efficiently recall semantic memory. The table also compares performance on strongly (such as “sky” and “blue”) and weakly associated words (such as “cat” and “paw”). The NS trial scored an average of 12.7% higher than the TSD trial. Some might argue that 12.7% too small to have any significance, the p-value of 0.04 shows that the difference in scores between NS and TSD are significant and not caused by chance.
Sleep deprived people struggled to quickly identify related words, a skill that requires the use of semantic memory. Sleep is a vital component in semantic memory recall. Although semantic memories are not the goal when pulling an all-nighter, the study is important because it shows that sleep affects memory recall efficiency which is a vital aspect needed to succeed on any test. Without being able to efficiently retrieve the information that our brain is storing, we are unable to perform our best. So, is it worth it to trade sleep for study time? If you cannot quickly retrieve the newly learned information, the answer is likely no.
*Novel Measures to Assess the Effects of Partial Sleep Deprivation on Sensory, Working, and Permanent Memory, Dominique Gosselin et al. 2017