The Effects of Sleep Time and Power Napping on Memory and Vigilance

This research investigated the effects of power napping and sleep time on verbal and visual memory performance and vigilance levels. This research was conducted because there is limited prior research that determines the beneficial effects of power napping on both verbal and visual memory performance and vigilance levels. In addition, prior research has concluded that going to sleep early enhances memory and vigilance. However the interaction of sleep time and power napping has not yet been investigated. This research hypothesised that power napping would significantly increase verbal and visual memory performance, as well as vigilance levels. It further hypothesised that participants who go to sleep late (after midnight) would benefit significantly more from a power nap, enhancing verbal and visual memory performance and increasing vigilance levels, in comparison to those who go to sleep early (before midnight). This research drew on the findings of prior research which investigated the impact of circadian rhythms and the stages of sleep on performance.

This experiment included 80 participants, 40 participants engaged in a 20 minute power nap whilst the other 40 participants engaged in a 20 minute rest period which involved reading magazines. In the power napping condition and non-power napping condition, 20 participants went to sleep before midnight and 20 participants went to sleep after midnight the night prior to the experiment. All 80 participants completed a verbal memory test, a visual memory test and a vigilance test. The results of the experiment found that engaging in a power nap did significantly increase verbal and visual memory, and participants who went to sleep after midnight had significantly increased verbal and visual memory performance in the power napping condition, compared to those who went to sleep before midnight. However, there were no significant difference between the power napping condition and non-power napping condition with regards to vigilance levels. There were also no significant difference between the early sleep time condition and late sleep time condition in the power napping condition on vigilance levels.