How daylight exposure affects our internal body clocks, impacting our sleep patterns — especially in winter.
Including: how naps affect the brain, how winter changes our sleep and how to wake up feeling relaxed and refreshed.
Including: how naps affect the brain, how winter changes our sleep and how to wake up feeling relaxed and refreshed.
Sleep and mental health are irrevocably intertwined — too little or even too much can both be injurious to mental and physical health.
Yet it seems to be a state over which we have so little control.
Sleep has naturally fascinated researchers, who have asked how naps affect the brain, how winter affects our sleep and how to wake up feeling relaxed and refreshed.
Studies have also explored how lack of sleep affects our emotions and whether, if we cannot sleep, we become a different person after midnight.
So, here are 10 psychology studies from the members-only section of PsyBlog covering the latest sleep science.
(If you are not already, find out how to become a PsyBlog member here.)
Disruption of deep sleep, which occurs more during the first part of the night, is linked to memory problems and the build-up of proteins in the brain that are linked to dementia.
The reason for these ultra-short awakenings is partly related to memory, the researchers think.
We ruminate at night and it becomes more difficult to control ourselves.
A sleep habit many people develop that unfortunately causes insomnia.
Sleep adapts to the seasons and human physiology is ‘down-regulated’ in the winter.
Around half of people in developed societies do not get enough sleep.
“How you wake up each day is very much under your own control, based on how you structure your life and your sleep.” – Professor Matthew Walker
Parasomnias include a whole range of sleep disorders that are surprisingly difficult to treat.
There is some stigma around napping, perhaps partly because excessive daytime napping can be a sign of Alzheimer’s.
Whether it is anxiety, schizophrenia, Tourette’s or depression, all have circadian rhythm disruption in common.
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Parasomnias include a whole range of sleep disorders that are surprisingly difficult to treat.
Larks tend to rise earlier while owls stay up late — each type extends the part of the day at which they feel their best.
Larks tend to rise earlier while owls stay up late — each type extends the part of the day at which they feel their best.
Morning types or ‘larks’ have superior verbal IQ, research finds.
Morning types are people who prefer to do demanding things earlier in the day, whereas evening types consider their best time to be later on.
Naturally, larks also tend to rise earlier while owls stay up late — each type extends the part of the day at which they feel their best.
The results come as a rebuff to other studies that have found the reverse, that it is owls that have the IQ advantage.
Dr Stuart Fogel, study co-author, how his study is different:
“Once you account for key factors including bedtime and age, we found the opposite to be true, that morning types tend to have superior verbal ability.
This outcome was surprising to us and signals this is much more complicated that anyone thought before.”
The study included 61 people whose ‘morningness’ or ‘eveningness’ was assessed, along with their cognitive abilities.
The results showed that people who were at their best in the morning scored higher on tests of verbal IQ.
Verbal IQ refers to being able to use language to achieve goals.
Critically, the researchers had to account for the fact that young people as a group tend to be evening types.
The fact that young people tend to be evening types may make it harder for them to get the best out of the school day, said Dr Fogel:
“A lot of school start times are not determined by our chronotypes but by parents and work-schedules, so school-aged kids pay the price of that because they are evening types forced to work on a morning type schedule.
For example, math and science classes are normally scheduled early in the day because whatever morning tendencies they have will serve them well.
But the AM is not when they are at their best due to their evening type tendencies.
Ultimately, they are disadvantaged because the type of schedule imposed on them is basically fighting against their biological clock every day.”
The study also found that people with regular daily habits tended to perform the best.
Dr Fogel said:
“Our brain really craves regularity and for us to be optimal in our own rhythms is to stick to that schedule and not be constantly trying to catch up.”
The study was published in the journal Current Research in Behavioral Sciences (Gibbings et al., 2022).
Long-held beliefs about sleep-wake patterns challenged: around half of all people are neither ‘larks’ or ‘owls’.
Half the people in the study, though, slept about an hour less than the recommended amount.
Half the people in the study, though, slept about an hour less than the recommended amount.
Sleeping between 7 and 8 hours a night is best for the brain, research concludes.
More or less sleep than this is linked to lower cognitive performance.
Half the people in the study, though, slept about an hour less than the recommended amount.
The brains of people who slept four hours or less were nine years older, cognitively.
Over-sleeping was also linked to worse cognitive performance.
Professor Adrian Owen, the study’s first author, said:
“We really wanted to capture the sleeping habits of people around the entire globe.
Obviously, there have been many smaller sleep studies of people in laboratories but we wanted to find out what sleep is like in the real world.
People who logged in gave us a lot of information about themselves.
We had a fairly extensive questionnaire and they told us things like which medications they were on, how old they were, where they were in the world and what kind of education they’d received because these are all factors that might have contributed to some of the results.”
The results come from over 40,000 people around the world who completed a survey and cognitive tests.
Lack of sleep — or too much — was bad for the brains of young and old just the same.
Dr Conor Wild, study co-author, said:
“We found that the optimum amount of sleep to keep your brain performing its best is 7 to 8 hours every night and that corresponds to what the doctors will tell you need to keep your body in tip-top shape, as well.
We also found that people that slept more than that amount were equally impaired as those who slept too little.”
The study was published in the journal Sleep (Wild et al., 2018).
There is some stigma around napping, perhaps partly because excessive daytime napping can be a sign of Alzheimer’s.
A sleep habit many people develop that unfortunately causes insomnia.
If poor sleep is contributing to dementia, then sleeping pills may be beneficial.
Around 40% of US adults say they have trouble falling asleep.
Around 40% of US adults say they have trouble falling asleep.
Writing a to-do list for the next day before bedtime helps people fall asleep faster, research finds.
The more specific the list, the faster people fall asleep.
Use this tip in concert with those described here: How To Fall Asleep Fast.
Dr Michael K. Scullin, who led the study, said:
“We live in a 24/7 culture in which our to-do lists seem to be constantly growing and causing us to worry about unfinished tasks at bedtime.
Most people just cycle through their to-do lists in their heads, and so we wanted to explore whether the act of writing them down could counteract nighttime difficulties with falling asleep.”
The 57 people in the study wrote for just five minutes before sleeping.
The study compared writing a to-do list with writing a list of completed activities before bedtime.
Dr Scullin said:
“There are two schools of thought about this.
One is that writing about the future would lead to increased worry about unfinished tasks and delay sleep, while journaling about completed activities should not trigger worry.
The alternative hypothesis is that writing a to-do list will ‘offload’ those thoughts and reduce worry,”
The research was conducted in a sleep lab and people had their electrical brain activity monitored overnight.
Dr Scullin was cautious about the results:
“Measures of personality, anxiety and depression might moderate the effects of writing on falling asleep, and that could be explored in an investigation with a larger sample.
We recruited healthy young adults, and so we don’t know whether our findings would generalize to patients with insomnia, though some writing activities have previously been suggested to benefit such patients.”
The study was published in the Journal of Experimental Psychology (Scullin et al., 2018).
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