Subscription 
When rules change, brain falters: study- 1-Aug-2012
Researchers from Michigan State University found that when participants in a task were given a set of rules which were later reversed, they repeatedly erred and had to work harder than when they were given the first set of rules.
"Imagine travelling to Ireland and suddenly having to drive on the left side of the road. The brain, trained for right-side driving, becomes overburdened trying to suppress the old rules while simultaneously focusing on the new rules," said Hans Schroder, who led the research.
"There's so much conflict in your brain that when you make a mistake like forgetting to turn on your blinker you don't even realise it and make the same mistake again. What you learned initially is hard to overcome when rules change," said Schroder.
The study was published in the journal Cognitive, Affective & Behavioral Neuroscience.
Study participants were given a computer task that involved recognising the middle letter in strings such as "NNMNN" or "MMNMM." If "M" was in the middle, they were to press the left button if "N" was in the middle, they were to press the right.
After 50 trials, the rules were reversed so the participants had to press the right button if "M" was in the middle and the left if "N" was in the middle.
Participants made more repeated errors when the rules were reversed, meaning they weren't learning from their mistakes.In addition, a cap measuring brain activity showed they were less aware of their errors.
When participants did respond correctly after the rules changed, their brain activity showed they had to work harder than when they were given the first set of rules.
"We expected they were going to get better at the task over time," said Schroder in a statement.
"But after the rules changed they were slower and less accurate throughout the task and couldn't seem to get the hang of it," Schroder added.
