The mere sight of your mobile phone can distract you - even if you are not using it.

Researchers at the University of Southern Maine found that when people are asked to do a complicated task they are less successful if their mobile is still out.

Those who put it in their pocket or their bag got on average 20 per cent higher in the test because they were more focused.

Researchers from the University of South Maine found that people were distracted by their mobile - even when it wasn't in use (shown). People who couldn't see their phone scored 20 per cent higher in a test than those who could see it. Just the presence of a phone was found to severely limit reaction times

The findings suggest that when we need to do some work the best thing to do is not just turn your phone off - but put it away as well.

The researchers asked two groups of students to carry out two different attention-sapping tasks, one of which was trickier than the other.

Firstly they were given a page of 20 rows of numbers and asked to circle one number in particular whenever they saw it.

STUDENTS ARE ADDICTED TO THEIR PHONES, CLAIMS STUDY Students spend up to ten hours a day on their mobile phones, according to a study published in September. Some even said they feel stressed if their phone is not in sight. A team at Baylor University in Texas found that female students spent an average of ten hours a day texting, emailing and on social media while their male counterparts spent nearly eight. Lead author James Roberts said the idea of becoming addicted to using a mobile phone was ‘an increasingly realistic possibility’. Advertisement

Secondly that they had to do the same and also cross off any two adjacent numbers in different rows that added up to the target number.

During both experiments, half the students kept their phones on their desks and the other half put them out of sight.

The researchers found that in both experiments, those who could not see their phones did better and scored an average of 26 compared to 21 if they could see their mobile.

Lead author Bill Thornton, a social psychologist at the University of Southern Maine, wrote that being distracted by your mobile has ‘obvious consequences’ such as worse reaction times.

He said: ‘The "constant connectivity" afforded by mobile technology has contributed to a preoccupation with the cell phone - an overwhelming majority of users check their cell phone upon waking and as the last thing before they go to bed’.

Such behaviour is typical of ‘behavioural addiction’ and ‘diminishes our ability to maintain attention’, Professor Thornton added.

Lead author Professor Thornton said such behaviour is typical of ‘behavioural addiction’ and ‘diminishes our ability to maintain attention’. Previous studies have found we are addicted to our phones, including one in September that said Students spend up to ten hours a day on their mobile phones

In his conclusion he wrote: ‘Results of two studies reported here provide further evidence that the ‘mere presence’ of a cell phone may be sufficiently distracting to produce diminished attention and deficits in task-performance, especially for tasks with greater attentional and cognitive demands.

‘The implications for such an unintended negative consequence may be quite wide-ranging (for example, productivity in school and the work place).’

A previous study illustrated the extent of the problem when it revealed that mobile users check their devices an average of 150 times a day as they cannot bear to be apart from them.