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Parents of children and teenagers have long been warned about the dangers of screen time and digital devices before bed – the worry being that screens could harm the sleep patterns of young people.

But do screens really hurt the length and quality of sleep? Our new research found that using screens in bed was worse for sleep than using screens for hours before going to bed.

Sleep guidelines recommend no screen use in the hour or two before bed. But we found screen time in the two hours before bed had little impact on young people’s sleep. Instead, it was screen time once in bed that caused problems.

Using cameras to track device usage and sleep, we found using a device in bed could cause more harm than screen time right up to bedtime. These findings challenge long-held assumptions about screen time at night and could help parents improve the quality of their children’s sleep.

Connecting sleep and screens

A number of global organisations recommend adolescents stop using devices in the hour or two before bed, and instead undertake activities like reading a book or quiet time with the family.

But these recommendations are based on research with a number of limitations. The studies were designed in such a way that researchers could link sleep and screens. But they don’t tell us if changes in how young people used screens had an affect on the length or quality of sleep.

Most of the existing research also used questionnaires to assess both screen time and sleep. Questionnaires are unlikely to capture true screen time accurately, particularly if you are interested in knowing more than just how long an adolescent has spent on their device.

To address some of these weaknesses in the previous research, we asked 85 adolescents aged between 11 and 14 to wear a body camera on their chest for the three hours before bed, for four nights.

These cameras faced outwards and accurately captured when, what and how adolescents used their screens. Because we were interested in overnight screen time as well, a second infrared camera was placed on a tripod in the teenagers bedroom and captured their screen time while in bed. The research participants also wore an actigraph – a watch-sized device that objectively measured screen time.

Teen nighttime activity

It quickly became obvious the adolescents spent a lot of their screen time while in bed.

Our analysis looked at two time periods – from the two hours before they got into bed, and from once they were in bed (clearly under the covers) until they put their devices down and were clearly trying to go to sleep.

Our data showed 99 per cent of the adolescents used screens in the two hours before bed, more than half once they were in bed, and a third even after first trying to go to sleep for the night. Just one teenager did not use screens before bed on any of the four nights.

The screen time before they got into bed had little impact on their sleep that night. However, screen time once in bed did impair their sleep. It stopped them from going to sleep for about half an hour, and reduced the amount of sleep they got that night.

This was particularly true for more interactive screen activities like gaming and multitasking – when they use more than one device at the same time (like watching a movie on Netflix on a laptop while playing Xbox on a gaming device).

In fact, every additional ten minutes of this type of screen time reduced the amount of sleep they got that night by almost the same amount – nine minutes.

Revisiting guidelines

Our research was an observational study looking at the established screen habits of young people.

The next step to better understanding this will be to conduct experiments that can actually prove different types and timings of screen time affect sleep.

That said, what we have already found challenges existing guidelines.

Screens at night may not be the bogey man they have been made out to be. But allowing young people to have screens in bed can be detrimental to their quality of sleep.

So the simple message might be to keep those devices out of the bedroom.

Rachael Taylor is Professor, Department of Medicine, University of Otago

This article is republished from The Conversation under a Creative Commons license. Read the original article here

New Delhi:

Does your work keep you glued to screens for a longer period? Beware, coupled with no physical activity, it might take a toll on your brain’s cognitive functions and lead to digital dementia, warned experts on Tuesday.

The term “digital dementia” means memory issues and cognitive deterioration brought on by over-dependence on digital devices like smartphones, computers, etc.

“Long periods of screen time can affect the brain’s cognitive functions,” Dr Vinayak Kshirsagar, Senior Laparoscopic Surgeon, DPU Super Speciality Hospital, Pimpri, Pune told IANS.

“This is basically because of the decreased attention span and prolonged screen time, which often involves sitting in a difficult posture on the bed or couch. This can cause various health-related problems, such as obesity, body aches, spine problems, and backaches,” he said.

Dementia is a broad term for a range of cognitive impairments that significantly affect an individual’s daily functioning.

While more common among older people, recent research has highlighted the association between a sedentary lifestyle and an increased risk of developing dementia, especially in younger adults. It emphasises the importance of physical activity in both prevention and management.

A 2022 study investigated the relationship between total dementia risk and sedentary activities, such as watching television and using computers, and found that regardless of physical activity levels, spending more time engaged in sedentary activities increases the risk of developing dementia.

Another study found individuals who used screens for more than four hours a day had a higher chance of developing vascular dementia, and Alzheimer’s disease.

“The symptoms of digital dementia include short-term memory loss, trouble remembering words and difficulty in multitasking, a decline of attention span and learning capacity. Its consequences are aggravated by a sedentary lifestyle characterised by long periods of inactivity when the person is tied to his desk and screen for a majority of the day,” Dr. Pawan Ojha, Director – Neurology, Fortis Hiranandani Hospital, Vashi, told IANS.

Prolonged periods of inactivity such as sitting or lying down while awake, are increasingly common in modern society. This lifestyle has been linked to various health issues, including obesity, cardiovascular disease, diabetes, and dementia.

“Physical inactivity can lead to structural changes in the brain, inflammation and reduces blood flow to the brain,” Dr (Lt Gen) CS Narayanan, VSM Chairman, Institute of Neurosciences, Manipal Hospital Dwarka, New Delhi, told IANS.

“This can also lead to changes in behavioural patterns because continuous digital processing means our memory isn’t being trained for short and fast-paced tasks. We’re not using all of our neuronal channels in the brain as much, which can lead to excessive anxiety, stress levels, and possible changes in behavioural patterns,” Kshirsagar said.

Narayanan said conditions like obesity and diabetes, which are exacerbated by inactivity, are also known risk factors for dementia.

Incorporating short, frequent breaks from sitting throughout the day can help reduce sedentary time. Simple activities like standing up, stretching, or taking a short walk can make a significant difference.

“Regular exercise, particularly aerobic activity, can improve cardiovascular health, reduce inflammation, and enhance neuroplasticity — the brain’s ability to reorganise itself by forming new neural connections. These benefits are critical in maintaining cognitive function and reducing the risk of dementia,” the expert said.

The experts also suggested moderate use of screen time. For general cognitive health, it’s critical to utilize digital technology carefully and have a balanced and healthy lifestyle.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

In this digital age, excess screen time has become one of the major health concerns, especially among young teenagers. It’s really hampering their physical growth, mental stability, and the time they usually spend outdoors. The educational departments and governments of the whole world are finding ways to deal with this global problem.

Other initiatives aimed at helping people overcome screen addiction include conducting workshops on how to reduce screen time, as evidenced by the evolution of terms such as “digital detox,” “screen fast,” “unplugging,” and “disconnecting from the digital realm.” These initiatives highlight the growing recognition of the need to strike a balance between technology and a healthy lifestyle. Now, France is going to put a ban on the use of smartphones at school for students up to the age of 15, seeking to give children a “digital pause.”

According to a release by the French government, the ban covers the use of mobile phones and any other electronic communications terminal equipment (tablets or smart watches, for example) within schools and colleges.

The law also allows the board of directors of high schools to introduce, in the internal regulations, a ban on the use of these devices by high school students. This ban is valid during school and extracurricular time. It is also effective during all school activities organised outside the school or educational establishment.

However, the law has provided some exceptions. Students with disabilities or a disabling health condition retain authorisation to use medical devices associated with communication equipment (devices allowing diabetic children to manage their blood sugar levels, for example).

Concerning conditional prohibitions, the law allows for the stipulation of circumstances, in particular educational uses, and places in which the internal regulations expressly authorise the use of a mobile phone by students. These are indeed cumulative conditions, the internal regulations having to specify both circumstances and places.