But while experts say the the act is a natural extension of the younger generation’s reliance on modern technology, scientists disagree on whether it is possible to send a text while technically asleep.

Dr Ron Kramer, of the American Academy of Sleep Medicine, said: “Texting for some of the younger generation is probably as ingrained as driving is for some people.”

According to Jan Van den Bulck, of the Catholic University of Leuven, Belgium, the mobile phone has almost become an extension of the younger generation’s fingers.

Sleep specialist Dr David Cunnington has advised people to keep their phones out of the bedroom if they want a good night’s sleep.

The expert at the Melbourne Sleep Disorder Centre, in Australia, added: “People are doing so much during a normal day that it can mean they feel like they’re on call even at night.

“Because it’s so easy to communicate with smartphones, it becomes more difficult to separate waking and sleeping lives.”

He said: “Emails can be sent to work colleagues and have much more serious consequences, whereas texts are more likely to be accidentally sent to a friend or family member.

“The key point is that people need to respect their sleep, and make an effort to switch off at night.”

Jessica Castillo, 24, of Italy, Texas, recently sent two multimedia text messages, apparently after falling asleep during an exchange with her boyfriend.

The first began “Baby u there? Need to tell somethin …” before it turned into nonsense.

To do so, she had to navigate 11 different stages, excluding the typing.