With their promise of improved mental abilities, it is easy to see why brain training games are so popular. But new research shows that the perceived benefits may be limited to memory instead of IQ.
Most people would love a boost in brain power. And marketing departments are quick to tap into these desires. But an advertisement promising to improve your intelligence may be too alluring to resist, and probably too good to be true.
Psychological scientist Randall Engle of the Georgia Institute of Technology explains:
"It is hard to spend any time on the web and not see an ad for a website that promises to train your brain, fix your attention, and increase your IQ. These claims are particularly attractive to parents of children who are struggling in school."
Prof. Engle believes the claims are based on evidence that shows a strong correlation between working memory capacity (WMC) and general fluid intelligence.
Working memory capacity - or short-term memory - refers to our ability to keep information either in mind or quickly retrievable, particularly in the presence of distraction. General fluid intelligence is the ability to infer relationships, do complex reasoning, and solve problems.
The link between WMC and fluid intelligence seems to suggest that increasing WMC should increase fluid intelligence, but, as Prof. Engle notes: "this assumes that the two constructs are the same thing, or that WMC is the basis for fluid intelligence."
No boost to intelligence
To test the theory, the team at Georgia Tech invited 55 undergraduate students to complete 20 days of training on certain cognitive tasks. To ensure the students remained motivated and engaged in their training, they were paid extra for improving their performance each day.
Students in the two experimental conditions trained on either complex span tasks, which have been consistently shown to be good measures of WMC, or simple span tasks.
With the simple span tasks, the students were asked to recall items in the order they were presented, while for complex span tasks, the students had to remember items while performing another task in between item presentations. A control group trained on a visual search task which, like the other tasks, became progressively harder each day.
The researchers administered a battery of tests before and after training to gauge improvement and transfer of learning, including a variety of WMC measures and the measures of fluid intelligence.
The results were clear: only students who trained on complex span tasks showed transfer to other WMC tasks. None of the groups showed any training benefit on measures of fluid intelligence.
Tyler Harrison, a Georgia Tech graduate student and lead author on the paper, says:
"For more than 100 years, psychologists have argued that general memory ability cannot be improved, that there is little or no generalization of 'trained' tasks to 'untrained' tasks. So we were surprised to see evidence that new and untrained measures of working memory capacity may be improved with training on complex span tasks."
The main benefit seems to be that this could have important implications for real-world multitasking.
But the benefits of training did not transfer to fluid intelligence. Prof. Engle points out that just because WMC and fluid intelligence are linked, it does not mean that they are the same.
As he sensibly points out:
"Height and weight in human beings are also strongly correlated, but few reasonable people would assume that height and weight are the same variable. If they were, gaining weight would make you taller and losing weight would make you shorter - those of us who gain and lose weight periodically can attest to the fact that that is not true."
Earlier studies, reported on Medical News Today, have linked intelligence to the ability to block out destractions, while another showed that keeping active mentally could preserve memory.
The researchers acknowledge that more work needs to be done. They plan to continue this research to see how training specific aspects of cognition can lead to positive transfer to other tasks, both in the laboratory and in the real world.Written by Belinda Weber