Sleep longer, take naps to do better at work
Recent sleep research has unearthed some fascinating correlations between the duration of time someone spends sleeping and his or her cognitive functions. One of the most extensive studies ever conducted on the link between sleep duration and cognition recently reported that sleeping more or less than seven to eight hours per night impairs specific cognitive abilities. Surprisingly, the brain researchers from Western University in Canada found that oversleeping can be just as detrimental to cognition as sleeping too little.
This massive worldwide survey also identified that getting too much sleep isn’t a problem for most of us; on average people around the globe only sleep about 6.3 hours per night. Unfortunately, this creates a sleep deficit that can cause the body, brain, and mind to function at a subpar level.
The good news is that another study by researchers at the University of Bristol in the UK reported that taking a power nap can improve domains of cognitive function associated with processing information below conscious awareness. This study, Nap Mediated Benefit to Implicit Information Processing Across
Age Using an Affective Priming Paradigm, was recently published in the Journal of Sleep Research. The primary goal of this study was to identify if a relatively short period of sleep helps people process unconscious information and how this might improve automatic reaction times.
For this pioneering research on how short bouts of sleep improve memory consolidation of implicit tasks, the researchers hid information by “masking” it and then presenting it to study participants without their conscious awareness. Although the “masked” information was hidden from conscious perception, this research shows that it was being absorbed on a subliminal level somewhere in the brain.
Sixteen healthy participants practised a masked task (unconscious processing) and a control task that involved conscious information processing. One group stayed awake after practicing both tasks while the other group took a 90-minute nap. Then, participants were monitored using an EEG as they performed both tasks again while researchers monitored pre-and-post nap brain activity.
The group that stayed awake throughout the experiment did not show significant improvements on either task. Interestingly, the researchers found that taking a nap improved the processing speed of the masked task — which required learning on an unconscious level — but not the control task, which involved explicit memory and conscious awareness. This suggests sleep-specific improvements in subconscious processing and that information acquired during wakefulness can be processed in deeper, qualitative ways during short bouts of sleep.
Although the latest study by co-author Liz Coulthard of the University of Bristol Medical School doesn’t explore the specific neural mechanisms involved in sleep-driven improvements to implicit information processing, in my mind the findings on nap-mediated unconscious learning dovetail with another recent study from Japan on how the brain acquires implicit motor control. A study by Takeru Honda and others at the Tokyo Metropolitan Institute of Medical Science found that people who practised
Getting too much sleep isn’t a problem for most of us; on average people around the globe only sleep about 6.3 hours per night.
an explicit hand-reaching motor task they were consciously aware of could quickly master poking targets on a computer screen with their index finger. However, implicitly mastering this skill on an automatic, unconscious level when their perception was purposely distorted took practice and time.
When study participants put on a pair of “prism glasses” that misdirected conscious perception from where a target was actually located, it took the unconscious mind about 10 tries to figure out how to automatically compensate — without thought — and implicitly hit a moving target in the bullseye. The paper, Tandem Internal Models Execute Motor Learning in the
Cerebellum, indicates that cerebellar functions are involved in both implicit (unconscious) and explicit (conscious) motor learning.