For those imprisoned in a stuffy lecture theatre or trapped in an everlasting telephone call, the urge to scribble idly on a bit of paper is often seen as an indication of boredom.

However, the latest research suggests that the humble doodle may actually help improve concentration.

Scientists at Plymouth University have found that doodling whilst undertaking a mundane task enables people to recall more information.

According to a study published today in the journal Applied Cognitive Psychology, participants in an experiment who were asked to doodle while listening to a dull phone message were able to remember 29% more than those who were not.

A total of 40 subjects were asked to listen to a two-and-a-half minute tape recording that gave the names of several people and places.

Half were asked to shade in shapes on a piece of paper at the same time, paying no attention to neatness.

After the tape had finished, the subjects were asked to recall the names of the eight people mentioned, as well as eight place names that had been included as incidental information.

Those who had been doodling while listening remembered an average of 7.5 names, compared with 5.8 for the non-doodlers.

Professor Jackie Andrade, who conducted the research, said that subconscious activities such as doodling could improve the performance of a task by preventing the mind from wandering.

She said: "If someone is doing a boring task, like listening to a dull telephone conversation, they may start to daydream.

"Daydreaming distracts them from the task, resulting in poorer performance. A simple task, like doodling, may be sufficient to stop daydreaming without affecting performance on the main task.

"In psychology, tests of memory or attention will often use a second task to selectively block a particular mental process. If that process is important for the main cognitive task then performance will be impaired.

"My research shows that the beneficial effects of secondary tasks, such as doodling, on concentration may offset the effects of selective blockade. This study suggests that in everyday life doodling may be something we do because it helps to keep us on track with a boring task, rather than being an unnecessary distraction that we should try to resist doing. If you are listening to a very boring lecture or phone conversation scribbling shapes on a piece of paper is better than letting your mind wander."

The research is being published to coincide with the sixth National Doodle Day, which takes place today.

Hundreds of celebrities, including Katherine Jenkins, Ricky Gervais and Robbie Coltrane, have created doodles to mark the event.

The sketches will be auctioned online to raise money for charities working in the fields of epilepsy and neurofibromatosis, a genetic disorder that can cause the formation of benign tumours.

Organisers have also invited schoolchildren to enter their doodles into a national competition for a small donation.

Psychology of a scribble THE doodle has long been the medium of choice for artistic simpletons, but many great men of history have been partial to a scribble.

Bill Gates, Franklin Roosevelt and Richard Nixon are all known doodlers. The sixteenth-century writer Erasmus drew comical faces in the margins of his manuscripts.

More recently, artists such as Cy Twombly have elevated the doodle into a legitimate field of work, blurring the line between painting and drawing.

Perhaps the most famous doodles today are the Google Doodles, the small drawings based on the search engine's logo which appear on its homepage.

Doodles are a product of the subconscious, unconstrained by artistic convention or aesthetic pressures, and studying the doodles a person leaves can reveal a surprising amount about them.

Psychologist Elaine Quigley, a former chair of the British Association of Graphologists, said the shape of a doodle, its size, colour and even its position on the page are significant indications.

"Boxes are all about putting things into some kind of order," she said. "Then you get female doodles like flowers, and sexual doodles - things like aeroplanes.

"Trees are astonishingly revealing. A strong trunk and structured branches mean the person is usually secure in who they are. A long, thin trunk means they are easily blown over."