While programs to improve students' working memory are among the hottest new education interventions, new studies are calling into question whether exercises to improve this foundational skill can actually translate into greater intelligence, problem-solving ability, or academic achievement. Working memory is the system the mind uses to hold information during decisionmaking and analysis. As much as half of the variation in individual intelligence can be explained by differences in working-memory capacity, research shows. Working memory has come to be considered by researchers and educators as a key leverage point in boosting brainpower overall--and programs designed to strengthen it are already finding their way into some schools and homes. But a systematic review of 23 studies on working-memory training programs, published online by the journal "Developmental Psychology," found such training produced few long-term benefits to working-memory skills and no improvements to other cognitive skills like verbal ability, attention, word decoding, or arithmetic. And a randomized, controlled study to be published online next week in the "Journal of Experimental Psychology: General," found that improving on a key task used in working-memory training did not lead to improvements on any of a battery of 17 cognitive-ability measures, including problem-solving intelligence, multitasking, and perception speed.