People who text and surf the internet while watching TV have less grey matter in their brains compared to people who use only one media device at a time, or only use devices occasionally
Multi-tasking shrinks the brain, research suggests.

A study found that men and women who frequently used several types of technology at the same time had less grey matter in a key part of the brain.

University of Sussex researchers said: 'Simultaneously using mobile phones, laptops and other media devices could be changing the structure of our brains.'

Worryingly, the part of the brain that shrinks is involved in processing emotion.

The finding follows research which has linked multi-tasking with a shortened attention span, depression, anxiety and lower grades at school.

The researchers began by asking 75 healthy men and women how often they divided their attention between different types of technology.

This could mean sending a text message while listening to music and checking email, or speaking on the phone while watching TV and surfing the web.

The volunteers were then given brain scans which showed they had less grey matter in a region called the anterior cingulate cortex (ACC).

The findings held even when differences in personality were taken into account.

The study, published in the journal PLOS ONE, is the first to make a link between multi-tasking and the structure of the brain.

Researcher Kep Kee Loh said: 'Media multi-tasking is becoming more prevalent in our lives today and there is increasing concern about its impacts on our cognition and social-emotional well-being.'

He added that more research is needed to prove that multi-tasking shrinks the brain.

This is because it is also possible that people with less grey matter in the ACC are more drawn to using lots of gadgets simultaneously.

Scientists have previously demonstrated brain structure can be altered on prolonged exposure to novel environments and experience.

Other studies have shown that training - such as learning to juggle or taxi drivers learning the map of London - can increase grey-matter densities in certain parts.

Experts have also warned of the harmful impact technology can have on our memory and attention span.

The University of California team commissioned a survey of more than 18,000 people aged between 18 and 99 and found 20 per cent had problems with memory.

Researchers were taken aback by the 14 per cent of 18 to 39-year-olds who also worried about their memories.

Multi-tasking with gadgets may shorten attention span, making it harder to focus and form memories, the researchers said, adding that youngsters may be particularly affected by stress.