Latest news with #NetherlandsInstituteForNeuroscience
Gizmodo
2 days ago
- Health
- Gizmodo
Brain Scans Reveal Why Waking Up Is Sometimes Such a Difficult Experience
Want to wake up feeling great? The secret might not be so simple as a multi-step nighttime routine, early bedtime, or a no-device rule. A new study suggests that how we fall asleep and how we wake up the next day may not be so similar as we once thought. Neuroscientists tracked 20 people's brain activity as they woke up from sleep—sometimes naturally, sometimes by setting off an alarm—recording more than 1,000 awakenings in total. They found a pattern of neural activity signaled waking, but that the pattern was slightly different in people who were deep in dream-laden REM sleep as opposed to those in non-REM sleep. And people woken from REM sleep were more likely to say they felt tired on waking. 'The surprise is how consistent [this pattern] was across every awakening and also how it related to the subjective measures,' Francesca Siclari, the study's senior author and neuroscientist at the Netherlands Institute for Neuroscience, told Nature. The results were published this week in Current Biology. Each participant had 256 sensors attached to their scalps, which allowed the researchers to track their brain activity at a second-to-second timescale. From there, the researchers were able to reconstruct a visual map of each participant's brain activity and compared it to how sleepy each participant said they were on waking. They found that when people were roused during REM sleep, a neural 'wave of activation' moved from the front to the back of the brain: the prefrontal cortex, which manages executive function and decision-making, fired up first, followed by a slow 'wave' of alertness that ended at the region associated with vision. During non-REM sleep, the wave started in a central 'hotspot' and then progressed along the same front-to-back pattern. The findings could help researchers tease out why some people who struggle with sleep find it hard to wake up feeling refreshed, although more work is needed to understand whether other issues during sleep, like movement, may be at play. Less subjective measures of wakefulness could also help refine the results. 'Knowing exactly how brain activity is characterized during a normal awakening [means] we can better compare it to these abnormal awakenings,' Siclari told Nature.
Daily Mail
21-06-2025
- Health
- Daily Mail
Can't sleep in the heat? Scientists reveal simple sock hack that's guaranteed to help you doze off
With the UK in the grips of 2025's first heatwave, many of us will be struggling to doze off amid the tropical heat. If you can't sleep in the heat, scientists may have a counterintuitive solution. Although it might seem bizarre, putting on a pair of socks before you head to bed could be the key to drifting off peacefully. Studies have shown that this simple hack can help you fall asleep faster, stay asleep longer, and get a better night of rest. Wearing socks has even been proven to be effective at bedroom temperatures up to 23°C - hotter than nighttime temperatures in many places across the country this weekend. This strange trick works because our bodies' sleep and temperature regulation systems are deeply linked. Professor Eus van Someren, head of the Department of Sleep and Cognition at the Netherlands Institute for Neuroscience, told MailOnline: 'The brain not only regulates body temperature, but also reads out skin temperature. 'It may interpret warm feet as the right moment to fall asleep.' Why should you wear socks to bed? Our core body temperature has a day-night rhythm, starting to drop in the evening to reach its lowest point around four in the morning. That means the best time to sleep is when the core body temperature is on its way down. Normally, your body would cool itself close to bedtime by sending blood to the skin in a process called distal vasodilation, which makes the skin hot. Professor van Someren says this is like 'opening the radiator in the heating system in your home.' When you put on socks, this increases the temperature of your skin and creates signals that your brain mistakes for the warming caused by vasodilation. Your brain will then believe that it is time to fall asleep, and you will find it easier to drift off. But wearing socks also helps you get to sleep in a more counterintuitive way. When our skin becomes hot, the brain's temperature control system sends a signal to the body telling it to start venting heat by sending hot blood into veins near the surface. This causes an increase in vasodilation, sending blood rushing to the skin and dropping the core body temperature down to safe levels. Dr Michael Gradisar, head of sleep science and clinical psychologist and Sleep Cycle, says that wearing socks can trick the body into triggering vasodilation. This, in turn, causes the core body temperature to drop and helps you drift off to sleep. Dr Gradisar says: 'For people who need extra help warming their feet to assist their natural thermoregulation, socks can be helpful.' That might be especially useful if you suffer from Raynaud's phenomenon, poor circulation, or other conditions that interfere with blood flow to the extremities. A study published in 2018 by researchers from Seoul National University found that wearing bed socks significantly improved sleep even when the room was a toasty 23°C. Those who wore socks to bed fell asleep 7.5 minutes faster on average and woke up more than seven times less frequently during the night. How can you get the most out of this trick? To make this trick work for you, it's important that you maximise the amount your core body temperature falls before bed. Studies of skin heating techniques show that the best results were achieved when the feet were warmed about one hour before bedtime. That means you should put on socks before you get into bed to trigger the core cooling process early. Wearing the right material can also make a big difference, as you don't want anything that will trap too much heat or moisture. Dr Gradisar says that 'natural fibres like wool help' since these offer the best balance of breathability and warmth. Likewise, a study of sleepers conducted at 30°C and relative humidity of 50 per cent found that those wearing Merino wool sleepwear got a better night's rest than those wearing cotton. Additionally, if you can find a way of cooling down your body while your feet stay hot, that will ensure the best temperature gradient for sleep. Dr Gradisar recommends using a fan or other means to try and keep the bedroom as cool as possible. However, with temperatures over 30°C forecast this weekend, it is also important to avoid making your feet too hot during the night. Professor Bill Wisden, an expert on the neuroscience of sleep from Imperial College London, told MailOnline: 'Heat is like any intrusive stimulus such as pain, or noise or vibration. It wakes you up. 'Even if the socks help you go to sleep, having hot feet in summer will wake you up!' So, if you do find yourself getting too hot as you doze, simply kick the socks off before falling asleep. The increased vasodilation will linger for a while afterwards, and exposing your feet to the air could produce an even greater drop in core temperature, helping you fall asleep faster and stay asleep all night. What if you find socks uncomfortable? Many people may find the idea of wearing socks to bed an extremely unpleasant thought. Luckily, if you are one of those people who like to let their feet breathe, there is another way to get the same effects. Anything you can do to raise the temperature of your skin before getting ready for bed will trigger the same vasodilation effects as putting on a pair of socks. Professor Wisden says: 'I recommend just before bedtime, take a hot shower or warm bath, even on a warm evening. 'At the end of the day, this raises the probability that you will drift off to sleep.' You don't even need to have a full bath or shower if that seems like too much effort. Studies have shown that simply bathing the feet up to the ankle in 40°C water for about 20 minutes, one to two hours before bed, helps people fall asleep about 10 minutes faster on average. So, although it might sound odd, if you want to beat the heat this weekend, the best thing to do is to get as hot as possible before bed.
