Three years ago Martha Farah, director of the Center for Cognitive Neuroscience at the University of Pennsylvania, discovered that the working memory of children raised in poverty is significantly less than the working memory of children raised in middle-class families. Building on this research, Gary Evans and Michelle Schamberg of Cornell University recently reported in Proceedings of the National Academy of Sciences that 17-year-olds who had spent their whole lives in poverty hold an average of 8.5 items in memory at any time, while those brought up in middle-class families can manage around 9.4 items. As The Economist (April 4) explains, “Working memory is the ability to hold bits of information in the brain for current use . . . and is a prerequisite for something to be learned permanently.” A person with a diminished working memory will not learn as fast or as well.
Perhaps more important, the researchers found that the reduced working memory correlates with signs of higher stress, as measured by higher blood pressure, higher concentration of stress hormones, and higher body mass index. The more time a child spends in poverty, the higher those stress factors become, and the lower his working memory. Using statistical analysis, the researchers found that a reduction in working memory was entirely predicted by the stress load. As The Economist points out, stress shrinks the volume of the prefrontal cortex and hippocampus, the parts of the brain most associated with working memory.
And while the researchers don’t mention it, their work suggests that a path away from the effects of lifelong poverty may be one that protects the child’s brain by teaching meditation, as well as exercise and sports.