Children who spend seven hours or more on smartphones and tablets are changing the structure of their brains and risking lower IQs and declining memory and cognitive function

An image of a brain while a child performs a working memory task, released by ABCD researchers. The regions in yellow and red are most active. Modern technology like smartphones, tablets and video games are physically changing children's brains

Children who use screens for seven hours or more a day are showing signs that their brain cortex is thinning prematurely.

The findings show that children are at risk of deteriorating memory function, perception skills and cognitive abilities, according to new major US study. 

The ongoing $300 million (£236mn) research is funded by the National Institute of Health and shows results of the effects of technology on children.   

Researchers made the early findings by scanning the brains of 4,500 children. 

Scientists are in the process of following more than 11,000 nine to ten-year-olds over the course of a decade.

The aim of the study, called Adolescent Brain Cognitive Development, is also to show how screen time affects emotional development and mental health. 

The researchers also determined that children who spend more than two hours of daily screen time score lower on thinking and language tests. 

The brain cortex is the outermost layer of neural tissue that processes information from the physical world. 

It is critical for cognitive functions such as perception, language, memory and consciousness but thins as we mature into old age.

Though the difference was significant from participants who spent less time using smart devices, the study director cautioned against drawing a conclusion.  

Dr Gaya Dowling, an NIH doctor working on the project, cautioned against drawing a conclusion because they aren't completely sure it's being caused by the increased use of modern technology.

'We don't know if it's being caused by the screen time. We don't know if it's a bad thing,' said Dr Dowling. 

'What we can say is that this is what the brains look like of kids who spend a lot of time on screens. And it's not just one pattern'. 

The scientists won't be able to draw a definitive outcome until they follow them over the course of several years.

Dr Dowling said: 'It won't be until we follow them over time that we will see if there are outcomes that are associated with the differences that we're seeing in this single snapshot.' 

A 2014 study showed that there is a direct correlation between the thickness of the brain cortex and IQ score.

The cortex begins to thin after the age of five or six as part of the normal aging process.

The findings showed that people with a significant increase in IQ did not have the expected cortical thinning and people with a significant decrease in IQ had exaggerated cortical thinning.

 A major data release of the initial data is scheduled for early 2019.

HOW SEVERE IS SMARTPHONE ADDICTION?

With the average age for a child to get their first phone now just 10, young people are becoming more and more reliant on their smartphones.

Worrying research from Korea University suggests that this dependence on the technology could even be affecting some teens' brains.

The findings reveals that teenagers who are addicted to their smartphones are more likely to suffer from mental disorders, including depression and anxiety.

Other studies have shown people are so dependent on their smartphone that they happily break social etiquette to use them.

Researchers from mobile connectivity firm iPass surveyed more than 1,700 people in the US and Europe about their connectivity habits, preferences and expectations.

The survey revealed some of the most inappropriate situations in which people have felt the need to check their phone – during sex (seven per cent), on the toilet (72 per cent) and even during a funeral (11 per cent).

Nearly two thirds of people said they felt anxious when not connected to the Wi-Fi, with many saying they'd give up a range of items and activities in exchange for a connection.

Sixty-one per cent of respondents said that Wi-Fi was impossible to give up – more than for sex (58 per cent), junk food (42 per cent), smoking (41 per cent), alcohol (33 per cent), or drugs (31 per cent).

A quarter of respondents even went so far as to say that they'd choose Wi-Fi over a bath or shower, and 19 per cent said they'd choose Wi-Fi over human contact.