As many as 10 percent of school-age children may suffer defects in working memory -- the brain's temporary storage bin -- which may explain why one child gets lost in algebra and another can't understand her history lesson, new research suggests.

"You can think of working memory as a pure measure of your child's potential," Dr. Tracey Alloway of Britain's Durham University said in a telephone interview. "Some psychologists consider working memory to be the new IQ because we find that working memory is the single most important predictor of learning."

Working memory allows people to hold and manipulate a few items in their minds, such as a telephone number. Alloway compares working memory to a box. For adults, the basic box size is thought to be three to five items. People who have more than that on a mental grocery list are likely to forget something.

"In children with learning difficulties, it becomes a huge issue, especially around middle school where the demands on working memory grow dramatically," said Dr. Mel Levine, co-founder of All Kinds of Minds, a nonprofit institute in Durham, North Carolina, that studies learning differences.

Levine said working memory allows a reader to remember what is at the beginning of the page when reaching the end of the page. Kids with trouble with active working memory get lost in the middle.

"One little girl told me recently, 'Every time I read a sentence it erases the one that was before it,"' Levine said in a telephone interview. "That's a perfect example of an active working memory dysfunction."

While he is not sure working memory can be expanded, Levine said children can be taught ways to function better in school.

For the girl with the reading problem, Levine's solution was for her to own a set of school books so she could underline key points when she reads. Then she can read those points into a digital tape recorder and play them back.

"While it did not fix her problem, it prevents it from causing too much trouble," he said. "She was very interested because she was telling her mother she was the stupidest kid in her class. Now she's telling people, 'I've got to work on expanding my active working memory.'"

(Xinhua/Agencies March 4, 2008)