Using strong and targeted but noninvasive magnets at specific sites in the brains of people with and without mild learning and memory problems, researchers report they were able to detect differences in the concentrations of brain chemicals that transmit messages between neurons. The strength of these magnetic fields allows the researchers to measure tiny amounts and compare multiple brain metabolite levels at the same time. These studies may ultimately help to reveal what initiates memory decline and may, perhaps, even predict dementia risk.