Enter the maze

A game set by sweat

an athlete shakes off sweat

At the very beginning of a video game, you have to decide how difficult you want the game to be. Sometimes, though, you choose wrongly, and get overwhelmed by tough parts of a level. The problem is, not many games let you go back and choose a different level of difficulty without restarting the entire game. It would be great if you could switch in the middle without losing all your hard work.

Some human-computer interaction researchers in Texas thought that they could do even better than that. What if the computer could sense when you were having trouble, and adjust the level for you? They began by hooking up a heat- sensing camera to the game and training it on players' foreheads. The idea was that as you become more stressed, your forehead heats up. If the researchers could tell what temperature signals that players have stopped having fun and have started feeling stressed, the game could be programmed to turn down the difficulty automatically.

That's just what they did. Over a series of experiments, they had people come into their lab and play a game. It started out easy, so that the players could get to know the game, and then the heat- sensing camera was turned on. The game would automatically adjust its difficulty if their forehead temperature suggested they were getting overwhelmed. The game also works the other way: if the computer thinks you might be bored, the difficulty level goes up. That way, with the help of a bit of fancy equipment and computer psychology, game players are never too bored and never too stressed. Just right.