How sleep helps us adapt our memories for future experiences.
How sleep helps us adapt our memories for future experiences.
Sleep helps to strengthen both old and new versions of an experience.Instead of overwriting old versions of a memory, the brain stores another copy of the same experience.Sleep keeps both old and new memories alive, which gives memory more flexibility.Dr Scott Cairney, who led the research said:
“Previous studies have shown sleep’s importance for memory.Our research takes this a step further by demonstrating that sleep strengthens both old and new versions of an experience, helping us to use our memories adaptively.In this way, sleep is allowing us to use our memory in the most efficient way possible, enabling us to update our knowledge of the world and to adapt our memories for future experiences.”
For the study people were learning the locations of words on a screen over two learning sessions.One group slept between learning sessions for 90 minutes, the other did not.The catch was that some of the words moved between training session.Those that slept in between had better memory for both the original location and the updated location.This suggested sleep had had a positive effect on both the new and old version of the memory.Professor Gareth Gaskell, study co-author, said:
“For the sleep group, we found that sleep strengthened both their memory of the original location as well as the new location.In this way, we were able to demonstrate that sleep benefits all the multiple representations of the same experience in our brain.”
Curiously, the study may also show how some inaccuracies in memories arise.After all, if we are carrying around multiple memories of the same thing, then it is easy for us to get confused.The study was published in the journal Cortex (Cairney et al., 2017).
How memories and dreams come together to help us solve problems at night.
How memories and dreams come together to help us solve problems at night.
Ever wondered why sleeping on a problem can make the answer seem clear?
Now, sleep scientists think they have a plausible theory.
While we sleep our brains shuttle backwards and forwards between different types of sleep.
Two of these together may provide the key to how we can solve problems overnight.
So-called ‘non-REM’ sleep helps us organise information.
REM stands for Rapid Eye Movement and this is the part of sleep in which we dream.
‘Non-REM’, then, is the part when we are not dreaming — sometimes when we are in deep sleep.
Then, REM sleep allows us to make unexpected connections between different memories.
This could be the source of our nighttime Eureka moments.
Professor Penny Lewis, the study’s first author, explained:
“Suppose I give you a creativity puzzle where you have all the information you need to solve it, but you can’t, because you’re stuck.
You could think of that as you’ve got all the memories that you need already, but you need to restructure them — make links between memories that you weren’t linking, integrate things that you weren’t integrating.”
During non-REM sleep, the hippocampus — a part of the brain critical to memory — decides what memories to replay.
Then, during REM sleep, when we dream, the brain is free to replay stored memories in any combination.
Hence the jumble of juxtapositions we get while dreaming.
Next morning the answer pops into our heads, seemingly unbidden, but actually the result of serious memory crunching.
Professor Lewis said:
“So, what we propose is that, if you’re stuck on some kind of problem, that problem is salient, and we know that salient things are replayed.
The slightly hypothetical part is that, when something else is randomly activated in the cortex that has an element that’s similar, you’ll form a link.”
The study was published in the journal Trends in Cognitive Sciences (Lewis et al., 2018).
Up to 10 percent of road traffic accidents have this psychological cause.
Up to 10 percent of road traffic accidents have this psychological cause.
Drowsiness is a major cause of road traffic accidents, involved in up to 10 percent of crashes.
The natural vibrations of a car make people sleepy just 15 minutes after setting off.
People reach significant levels of drowsiness after 30 minutes and peak drowsiness after 60 minutes.
The Australian researchers hope the finding can be used to help design new seats to keep drivers awake.
Professor Stephen Robinson, who led the study, said:
“We know 1 in 5 Australians have fallen asleep at the wheel and we know that drowsy driving is a significant issue for road safety.
When you’re tired, it doesn’t take much to start nodding off and we’ve found that the gentle vibrations made by car seats as you drive can lull your brain and body.
Our study shows steady vibrations at low frequencies — the kind we experience when driving cars and trucks — progressively induce sleepiness even among people who are well rested and healthy.
From 15 minutes of getting in the car, drowsiness has already begun to take hold. In half an hour, it’s making a significant impact on your ability to stay concentrated and alert.
To improve road safety, we hope that future car seat designs can build in features that disrupt this lulling effect and fight vibration-induced sleepiness.”
Dr Mohammad Fard, study co-author, said:
“We want to study a larger cohort, particularly to investigate how age may affect someone’s vulnerability to vibration-induced drowsiness as well as the impact of health problems such as sleep apnea.
Our research also suggests that vibrations at some frequencies may have the opposite effect and help keep people awake.
So we also want to examine a wider range of frequencies, to inform car designs that could potentially harness those ‘good vibrations’.”
Discover the top 10 myths about sleep and why they’re wrong. Improve your sleep quality with evidence-based insights and tips.
Sleep is a vital part of our overall well-being, yet misconceptions about it are widespread.
Common myths about sleep
Myth: Snoring isn’t harmful
Many people assume that snoring is a harmless annoyance, but this is not always the case.
In fact, chronic snoring can be a sign of sleep apnoea, a condition that disrupts breathing during sleep.
Sleep apnoea can lead to serious health issues, including heart disease, high blood pressure, and daytime fatigue.
If snoring is frequent and accompanied by gasping or choking sounds, it is essential to seek medical advice.
Myth: You can ‘catch up’ on sleep
The idea that you can make up for lost sleep by sleeping more on weekends is a common misconception.
While extra sleep might help you feel temporarily refreshed, it cannot fully reverse the effects of chronic sleep deprivation.
Maintaining a consistent sleep schedule is key to long-term health and well-being.
Myth: Older adults need less sleep
It is often believed that sleep requirements decrease with age.
However, adults of all ages generally need seven to nine hours of sleep each night.
Although older individuals may experience changes in sleep patterns, such as waking up earlier, their need for sleep remains unchanged.
Myth: Alcohol before bed improves sleep
Some believe that a nightcap can help them fall asleep faster.
While alcohol might initially have a sedative effect, it disrupts the sleep cycle, particularly REM sleep, which is crucial for mental and emotional restoration.
This can leave you feeling tired and unrefreshed the next day.
Myth: Sleeping with a light on is harmless
Sleeping with lights on may seem harmless, but it can interfere with the quality of your sleep.
Exposure to light during sleep can suppress melatonin production, a hormone essential for regulating the sleep-wake cycle.
To optimise your sleep environment, aim for total darkness.
Lesser-known myths about sleep
Myth: Your body adapts to less sleep over time
Some people believe they can train their bodies to function well on minimal sleep.
In reality, chronic sleep deprivation leads to cumulative deficits in cognitive performance, mood, and overall health.
Even if you feel accustomed to sleeping less, your body and mind still require adequate rest.
Myth: Napping compensates for poor nighttime sleep
Although naps can boost alertness and performance, they do not replace the restorative effects of a full night’s sleep.
Relying on naps instead of consistent nighttime sleep can disrupt your body’s natural sleep rhythm.
Myth: Falling asleep anytime, anywhere is a sign of a good sleeper
Falling asleep instantly might seem like a sign of excellent sleep health, but it could indicate sleep deprivation or an underlying sleep disorder.
Healthy sleepers generally take 10 to 20 minutes to drift off.
Unique insights into sleep misconceptions
Myth: Sleeping more on weekends can counteract weekday sleep loss
Many people sleep in on weekends to make up for insufficient sleep during the week.
However, irregular sleep schedules can disrupt your circadian rhythm and lead to poor sleep quality over time.
Consistency is key to maintaining good sleep hygiene.
Myth: Exercising late at night doesn’t affect sleep
While exercise is generally beneficial for sleep, vigorous activity late at night can delay sleep onset for some people.
Light or moderate exercise earlier in the day is a better choice for promoting restful sleep.
Myth: Watching TV in bed helps you fall asleep
Many people use television as a way to wind down before bed.
However, screen time exposes you to blue light, which can suppress melatonin production and make it harder to fall asleep.
Creating a screen-free bedtime routine can significantly improve sleep quality.
Myth: More sleep is always better
While insufficient sleep is harmful, excessive sleep can also be linked to health problems such as depression, diabetes, and cardiovascular disease.
Aim for the recommended amount of sleep to strike a healthy balance.
Myth: Sleep needs are the same for everyone
Another common misunderstanding is that everyone requires the same amount of sleep.
Sleep needs vary based on factors such as age, genetics, and lifestyle.
Listen to your body and prioritise the amount of sleep that leaves you feeling rested and alert.
Myth: Waking up in the middle of the night means poor sleep
Waking up briefly during the night is a normal part of the sleep cycle and does not necessarily indicate poor sleep.
Most people experience short awakenings between sleep stages, which are usually forgotten by morning.
If you frequently wake up and struggle to fall back asleep, it may be worth evaluating your sleep environment or habits.
Conclusion
Understanding and addressing sleep myths is essential for improving your sleep health and overall well-being.
By debunking these misconceptions and adopting evidence-based practices, you can create better habits for restful and restorative sleep.
Remember, sleep is not a luxury but a necessity, and prioritising it is one of the best investments you can make for your health.
Adopting consistent routines, maintaining a healthy sleep environment, and staying informed about sleep science can help you achieve the quality rest your body needs.
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