A new investigation has revealed that computer games contain influential psychological devices that make some people play compulsively.
A simple technique based on a 1950s study of rats feeding themselves by pressing a lever, which encourages repeat behaviour by rewarding it at random, has effectively been adapted for use in gaming and is feared to encourage addiction.
The programme, Panorama: Addicted to Games, quoted award-winning computer games designer Adrian Hon, of SixToStart, who admitted that that the technique once used on rats was now common place in computer games.
"In the 1950s scientists discovered that rats which had been trained to feed themselves by pressing a lever, would press it obsessively if the food was delivered randomly," the Daily Mail quoted him as telling BBC.
"People have discovered that this works on humans as well. If you give people a lever or a button to press and give them random rewards, they will press it all the time," he said.
In computer games, instead of food, players are randomly rewarded with extra lives or extra in-game features. The idea is to create a compulsion loop that keeps them wanting to play on.
The technique, called the variable ratio of reinforcement (or operant conditioning) is simple but powerful and is thought to be one of the reasons people become addicted to slot machines.
Hon added, "I think people don't necessarily understand how powerful some game mechanics can be. It's one thing to think "OK, I''m playing too much," but it's another to just stop playing, because some games are designed in a manner that you just don''t want to leave."
He warned that more and more children and young people in particular could be affected because games are becoming much more widespread and much more powerful.
Currently computer game addiction is not recognised as a medical condition but Mark Griffiths from Nottingham Trent University's International Gaming Research Unit has warned the issue needs further investigation.
He said, "People put money into alcohol and tobacco addiction maybe even gambling addiction but in gaming addiction it''s kind of so new people don''t see it as an important research area to look into."
He added that for many people the psychological ''trick'' employed by games would not be a problem but admitted that if people had a "vulnerability or susceptibility to addiction that will keep you in the game probably far in excess of what the normal person would do."