There's a significant controversy over the value of games that are designed to improve people's mental faculties, as some studies have indicated that brain training only helps prepare you for similar tasks, while others indicate that general improvements are possible. But there turns out to be a type of game that is known to boost a variety of skills, from decision making to tracking multiple objects: standard action games. A study, released today by Current Biology attempts to explain how these video games can produce such wide-ranging improvements.

The authors of the study argue that the root of all these tasks involves making a probabilistic inference, where complete information is missing, so people have to make a best guess based on known odds. Video gaming, in their view, increases the efficiency at which people can process the odds and make an accurate decision—gamers simply can do more with less. As a result, any task of this sort sees benefits.

The work started with two sets of subjects, gamers and non-gamers. Both were shown a screen that had a set of randomly moving dots, and asked to determine whether there was any coherent motion, meaning that, despite the apparent randomness, the dots had a tendency to head in a single direction. The participants had to decide when they had seen enough motion to make a decision, and they also had to pick an accurate direction. The former involves a probability judgement: have you seen enough to know that you can detect a trend?

When set loose on this task, both groups performed equally well in terms of accuracy, but the gamers produced the response more quickly than their peers. The same thing happened when the test was switched to a similar task based on tonal differences, indicating the success of gamers wasn't simply the result of their focus on visual cues.

Of course, as the authors note, this doesn't demonstrate causation: "It could also be the case that are individuals who have been born with improved abilities at performing probabilistic inferences." To rule this out, they took the non-gamers and gave them 50 hours of training and practice on action games (a control group learned to play slower-paced games). After the training, the same sort of pattern emerged, with the action gamers displaying an enhanced decision time.

The other issue they controlled for was twitchiness—gamers might get the task done more quickly simply because they could hit the key required to complete it faster. To eliminate this possibility, they showed the random motion (or played the tone) for fixed periods of time, and then let the subjects provide an answer at their leisure. When the time allowed for the test was short, gamers were more accurate than their peers. Overall, this supports the conclusion that they can do more with less information.

How might this actually work on the biological level? The authors favor a model where there's a two-part system for judging probabilities: one part registers the relevant information, then transfers it to a second that integrates the information and makes a probability judgment. They argue that gaming enhances the connection between the two, allowing more information to be transferred per unit time. With the additional info, the part of the brain that performs the evaluation can do so more quickly.

Why should gaming exercise this bit of the brain? In short, because action games place a premium on variety and novelty. "Unlike standard learning paradigms, which have a highly specific solution," they argue, "there is no such specific solution in action video games because situations are rarely, if ever, repeated."

The last question they address is why, if this sort of sped-up evaluation is so useful for a variety of tasks, aren't we all born with the abilities of gamers? Here, they claim to have information that they've not yet published, which indicates that shuffling too much information to the evaluation center actually overloads it, leading to poor performance. We'll have to see if that paper ever makes it to press before evaluating whether that's the case.

In the meantime, you've got one more excuse to go out and buy Halo: Reach.

Current Biology, 2010. DOI: 10.1016/j.cub.2010.07.040 (About DOIs).