It is a condition which leaves sufferers detached from the world, unable to understand the things the rest of us take for granted.

But new research could help autistic children get back in touch with society, courtesy of The Simpsons. Nick Morrison reports.

MARTIN likes to watch his Thomas the Tank Engine videos. When he has watched them once, he likes to watch them again. And again. And again. He can quite happily spend a whole afternoon seeing what Thomas and his friends Henry, James, Gordon and the rest, and, of course, the Fat Controller, get up to. Martin is 13.

When he's not watching his videos, Martin likes to flap his fingers in the air. If he can find a wheel, he will spin it and stare, fascinated, as it revolves. Show him a buzzer and he will press it repeatedly.

Martin is autistic, a condition which has made him detached from the rest of the world. He doesn't understand the world the way you and I do: he can't tell the difference between a living and an inanimate object; facial expressions have no meaning for him, and he finds it difficult to communicate. He couldn't speak until he was six and his first word was 'McDonald's'.

But Martin's obsession with watching Thomas the Tank Engine holds a clue to a possible source of help for autistic children. Like most autistic people, he finds comfort in repetitive behaviour, in doing the same things again and again. And particularly in watching the same television programmes over and over. And this has prompted Martin's mother Becci Stevens-Platt to look for ways of helping autistic children get in touch with the world.

Becci, a psychologist at Northumbria University, believes that doing the same thing over and again is an autistic person's way of moderating their own behaviour, of calming them if they are overactive and stimulating them if they are underactive, affecting their level of psychological arousal.

"What they're doing is acting on instinct - they're doing what comes naturally in order to make themselves feel better," she says. "I'm hypothesising that the performance of these rituals, these obsessions, this repetitive behaviour, is affecting their level of psychological arousal and bringing it back to the norm."

This has led Becci to devise a research project based on the effects of watching a favourite television programme.

It starts with the theory that, unless we find something fascinating we have to concentrate on it, and that this wanes after some time, but that we can restore concentration if we are in a certain environment, dubbed a "restorative environment".

One sign of our ability to concentrate is the hormone cortisol, an indicator of stress. Tests have found that after spending just half an hour in a restorative environment, cortisol levels can drop dramatically.

In a pilot study, Becci tested the reading ability of a group of volunteers and then sat them in front of their favourite television programmes, which ranged from The Simpsons and Six Feet Under to The Premiership. Then Becci repeated the reading test and took saliva samples to measure cortisol levels. The results showed that after watching their favourite shows, the volunteers showed significant gains in their reading ability, and significant falls in their cortisol levels.

The next step is a more extensive study, again with volunteers watching their favourite programmes, but this time with another group, watching video tapes of a mishmash of programmes, the result of channel hopping, to provide a standard against which to measure the first group's progress. Becci is now analysing the collecting the results of this study.

"I expect to find the same results as in the pilot, whereby the cortisol will be substantially lower for the people who had the restorative experience, and for the non-restorative group I expect the cortisol will be higher and their reading ability will be worse," she says.

If this is borne out by the research, it indicates that concentration levels can be improved by exposure to a restorative environment. And the implications for autistic children could be highly significant. Because their condition means they cannot relate to the world in the same way you or I do, things we take for granted, autistic children have to learn.

"Autistic people don't understand the world the way you and I do, they don't understand the things that you and I understand instinctively," says Becci. "For instance, facial expressions: autistic people don't understand facial expression or tone of voice.

"If I said 'For God's sake', you would have an idea that I had had enough, but they would think 'What is for God's sake?'. They don't understand the difference between a living person and an inanimate object. My son has told me there is no difference between me and a pot plant; he doesn't see that we have feelings. He will sit on his sister and I say 'Get off, it hurts', and he says 'I can't feel anything; it isn't hurting'."

But while this understanding does not come instinctively to autistic children, it can be learned, albeit through a gradual and painstaking process. By associating different expressions to particular reactions, for example, an autistic person can learn that someone else does not like what is happening, even if they don't necessarily appreciate that the other person is in pain, for example.

And this is where Becci's research comes in: if we can understand how a restorative environment works, we may be able to determine what needs to happen to get the optimum level of concentration out of an autistic child, helping end their isolation from the rest of the world.

And by understanding how these restorative environments work, it may be possible to develop them into a clinical tool to manage the condition of autism.

"Instead of understanding these things instinctively, autistic people have to download the information if they are going to function, and this could well make that downloading easier, it could make this emotional understanding, an area where they have great impairment, easier," she says.

'This is an area where it would be exceptionally significant if this theory were found to be the case. It is my hope that it would enable them to function within the world more easily. That download time could be reduced and made more efficient, enabling them to function more easily in society.

"We can't cure autism. It is not a death sentence, but it is a life sentence. But there are autistic people who are contributing to society, and it may well be easier for others to do the same. They do have differences, and those differences make it more difficult to participate in society, but if we're able to make use of restorative environments they could participate more fully."