Ever woken up tired after full night's sleep? Neuroscientists study brain scans to find out why
A new study, published in Current Biology, looked at how our brain works during the time when we wake up. Scientists at the Netherlands Institute for Neuroscience tracked the brain activity of 20 people, recording more than 1,000 wake-ups, some natural, others triggered by an alarm.
'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 a neuroscientist at the Institute, was quoted as saying by Nature.
Each person wore a special cap with 256 sensors that picked up brain signals every second. By watching how the brain 'turned on,' the researchers found that the way people woke up depended on which stage of sleep they were in.
When people were woken up during REM sleep– the stage when we usually dream, they were more likely to feel tired and slow. That's because their brain switched on in a certain order. First, the front part of the brain (which helps with thinking and decision-making) becomes active. Then, a slow wave of activity moves to the back of the brain, where we process what we see.
In contrast, people woken from non-REM sleep had a slightly different pattern. The brain wave started more in the middle and moved in the same direction but may have felt more natural.
This research could help doctors better understand why some people wake up feeling refreshed while others feel tired, even if they slept for the same amount of time. It might also help in studying sleep disorders or problems like feeling tired all the time.
'Knowing exactly how brain activity is characterized during a normal awakening [means] we can better compare it to these abnormal awakenings,' Siclari said. While more studies are needed, especially to see how other factors such as body movement affect sleep, this study shows that how we wake up matters just as much as how long we sleep.
(This article has been curated by Kaashvi Khubyani, who is an intern with The Indian Express)
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Indian Express
an hour ago
- Indian Express
Study led by IISER Pune decodes mechanisms that help plants regrow injured parts with original shape
Gardeners are often seen pruning shrubs or tree branches to maintain plant health and promote fresh growth. Soon, however, the pruned branches regrow with stunning resemblance to their original form. An international group of scientists, led by biologists at the Indian Institute of Science Education and Research, Pune (IISER), has now zeroed in on the key mechanisms in plants that help restore damaged parts to their original shape. Unlike animal cells, plant cells are far more rigid and depend more on growth rates and anisotropy (how a material's physical characteristics change depending on its direction) during cell regeneration. Roots are important facilitators that support nutrient intake. Their naturally tapered shape and conical tip aid better soil penetration. When they get damaged due to natural or external causes, it is observed that the lost cell types and layers get restored and the root regrows to the original tapered shape. In the latest paper published on July 25 in the journal Current Biology, mathematicians and physicists from IISER, Pune and Thiruvananthapuram, Netherlands' Wageningen University, and UK-based John Innes Centre, have attempted to track the mechanisms that may be responsible for restoring the root's tapered shape. In the study, the researchers describe a distinct geometric pattern as per which plant roots regrow after being damaged. This understanding, they said, could help establish fundamental cellular processes, like cell shape and cell regeneration in plants and, in particular, plants vital for food cultivation and securing food security. Instinctive responses of injured roots The group studied the regeneration of the Arabidopsis thaliana root after it was surgically chipped off. They observed notable behaviour in the root regrowth from the 12th hour since being chipped. Instinctively, the injured root's first response was to generate new cells at the wound site. And their goal was to remain oriented in the right direction and help restore the shape and function of the root and maintain its original function. 'The usual cuboidal root cells got morphed into rhomboid shapes. These altered cells then divided diagonally, producing triangular prism-like cells. The diagonal divisions redirected the growth of neighbouring cells along a slanted path — collectively recreating the lost tapered tip,' Kalika Prasad, biologist at IISER-Pune and co-author of the paper, told The Indian Express. After about 18-19 hours post-cutting, the previously flat root end had grown and bulged. By 24 hours, it had become more prominent, indicating the onset of some trigger mechanisms. Corresponding to about 12 hours post the injury, the researchers said, a mechanical tension was noted developing during the growth stage of the injured root. And this tension, they said, guided and controlled the new cells to align and develop in a certain geometric manner. The root tip has multiple cell layers. While cells in the outermost layer grow slower, the cells present in the innermost layer grow rapidly. 'This differential growth then leads to build up in mechanical tension within the cells and, as a response, their shape or geometry starts aligning. In the end, we found the regrown root to have restored perfectly with respect to cell types and the shape. It functioned optimally like an uninjured root,' Prasad said. Similar post-injury cell regeneration behaviour was demonstrated by a mustard plant called Brassica, which the team tested.
The Print
a day ago
- The Print
COVID-19 pandemic may have aged your brain, even if you weren't infected, finds UK study
According to the researchers, however, these changes could be 'partially reversible' but the most significant aspect highlighted in the study was how much simply living through the uncertainty and isolation of the pandemic affected brain health. Using brain scans from nearly 1,000 healthy adults from before and after the pandemic, researchers found signs of faster brain ageing, especially in older adults, men, and those from disadvantaged backgrounds. Of these samples, those who were infected with COVID-19 also showed some decline in thinking speed and flexibility. But overall, the pandemic's stress alone did shift brain structure in all individuals whose scans were reviewed. New Delhi: A new study from the University of Nottingham has found that just living through the COVID-19 pandemic may have aged people's brains faster, even if they never got infected with the virus itself. The peer-reviewed study was published on 22 July in the journal Nature Communications and is based on data from the UK Biobank Study. It's a powerful reminder that our environment matters for our brain's growth. Read more here. Also Read: A UK health study has collected a whopping 100,000 full-body scans, and Neanderthals had 'family recipes' Spiders originally came from the sea? Next, we might have evidence that spiders could have originally been sea creatures. At least that is what a new peer-reviewed study published in the journal Current Biology on 22 July suggests, after researchers closely examined a preserved fossil from half a billion years ago. The fossil is called Mollisonia symmetrica, and it has a nervous system very similar to that of modern-day arachnids like spiders and scorpions. Until now, scientists thought these creatures only evolved once their ancestors moved onto land 400 million years ago and have remained the same ever since. But this new study flips that theory on its head, quite literally. It cites evidence of the brain of the fossil Mollisonia, which shows a reversed organisation—a signature trait seen in today's arachnids. This arrangement may have given them faster reflexes, better control, and precision, which are all traits modern-day spiders use to hunt and weave webs. The fossil places Mollisonia as a close relative of modern arachnids, meaning these creatures might have started evolving in the ocean long before they crept onto land. Read more here. Scientists genome sequence 100-yr-old Spanish Flu virus A 100-year-old lung sample from Switzerland helped scientists decode the deadliest flu in human history. A new peer-reviewed study by researchers from the Universities of Basel and Zurich published in BMC Biology Journal on 1 July sequenced the genome of the 1918 'Spanish flu' virus. They used preserved tissue from a young patient who died during the pandemic's first wave in Switzerland. The Spanish flu that spread across Europe and Asia in the 1910s is said to have killed between 20-100 million people. By decoding the genome, scientists now have insights into how this flu had already adapted to humans early on. They found three key mutations in the genome—two which helped the virus evade the human immune system, and one which boosted its ability to infect human cells. What makes this study stand out is also how they conducted the study. In viral flus, the genetic information rests in the RNA, not the DNA. The RNA is very quick to degrade but these scientists developed a method to recover ancient viral RNA. This technique could open the door to learning more from historic outbreaks. Read more here. Arctic winter is melting, and researchers have noticed it A group of scientists led by Dr James Bradley from Queen Mary University, London, published a commentary in Nature Communications on 21 July talking about the 'shockingly warm' winter conditions in the Arctic. The team described how they had geared up for winter Arctic fieldwork in Svalbard, wearing layers of thermal clothing, only to find themselves drenched in rain, standing on bare grass, and working without even needing gloves in what is supposed to be the middle of winter in February 2025. Svalbard is a Norwegian archipelago located where the Arctic Ocean converges with the Atlantic Ocean. In the commentary, they raised alarms about melted snow pools, blooming vegetation, and rain replacing snow in the Arctic Circle during winters. Svalbard is heating up six to seven times faster than the global average, and the Arctic winter is no longer reliably frozen, said the team. These conditions not only disrupted their research but also raised safety concerns, like how to retreat from polar bears without their snowmobiles working. The team warns that winter warming in the Arctic is not a fluke but rather the new norm. The message sent by the commentary is clear: climate policy needs to catch up, and fast. Read more here. Also Read: A fiery side-effect of melting glaciers & paging Dr Droid for gallbladder surgery
Time of India
a day ago
- Time of India
Sweet isn't always simple. A parent's guide to raising sugar-smart children
Parenting in an era of rising obesity is challenging, to say the least. Add to that the culture of rewarding children with sweet treats for good behaviour, and the nutritional dilemma for parents only deepens. Chocolate for a good grade, ice cream after finishing a school project, superhero-themed birthday cakes — the list goes on. All this comes at a time when reports suggest that sugar consumption in CBSE-affiliated schools may soon be monitored through 'sugar boards.' At home, though, some parents may still wonder: how bad can sugar really be, especially when, according to old-school thinking, it's considered a source of 'energy'? Here's the deal: a 2024 study published in the journal Nature found that limiting sugar intake in babies can significantly reduce their risk of developing diabetes. 'Excessive consumption of sugar in early life can contribute to obesity and fatty liver disease in children. Also, overconsumption of sugary drinks can lead to abdominal bloating and in some cases GI (gastrointestinal) discomfort too,' says Dr Sarath Gopalan, senior pediatric gastroenterologist, Madhukar Rainbow Children's Hospital, Delhi, and National President of Nutrition Society of India. The 'math' of sugar intake As per WHO's revised guidelines, only 5% of your calorie intake should come from sugar compared to the previously recommended intake of 10%. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like She Was Everyone's Dream Girl In 90's, This Is Her Recently The Latest Article Undo Ishi Khosla, nutritionist and founder of Whole Foods, Delhi, simplifies the 'consumption scale' jargon: 'When we say that total daily sugar intake should not exceed 5% of daily calories, it means that on a standard 2,000 kcal diet, this amounts to a maximum of five teaspoons of added sugar per day. ' This scale is meant for both children and adults. 'WHO recommends further sugar reduction for children to below 5% of total energy intake for additional health benefits like reduced risk of obesity and dental caries,' adds Khosla. This translates to 2-4 teaspoons of added sugar for children over two years of age. For children up to two years, the Indian Council of Medical Research and the National Institute of Nutrition recommend no added sugar. Infants and toddlers can get their sugar from natural sources like milk and fruits. Understanding what added sugar is crucial. 'Added sugar refers to sugars that are not naturally present in whole foods like fruits or milk but are added during processing or cooking. While natural sugars like lactose in milk or fructose in fruits come with fibre, vitamins, and minerals, added sugars are simple carbohydrates that offer empty calories,' explains Ritika Samaddar, chief clinical nutritionist, Max Healthcare, Saket, Delhi. It becomes more complex because added sugar is 'hidden' in most processed foods like packaged juices, instant noodles, bread, biscuits, sauces and even in products that seem healthy such as infant cereals, flavoured yoghurt and nutritional/energy drinks. Spread out the treats It's a good idea to be mindful while giving sugar-based treats to kids during social occasions and outings. Khosla advises parents to try and restrict children's ice cream consumption to 'two small scoops a month'. 'Parents can spread out sugar intake across the week rather than letting kids indulge on one day and exceed recommended intake limit. Excessive sugar leads to energy spikes that affect mood in children prone to mood swings and those with conditions like attention deficit hyperactivity disorder. If your child is going to eat cake at a birthday party, try not to give anything that contains added sugar all day,' says Geetika Ahluwalia Chhatwal, nutritionist and diabetic educator. This kind of 'policing' is tough with lucrative sweet foods all around and colourful advertisements aimed at enticing children, but it's worth the extra effort to teach kids the importance of sugar management.
