If possible, always try to break up learning into separate sessions, rather than studying in a nose-to-the-grindstone marathon, according to Doug Rohrer, PhD, associate professor of psychology at the University of South Florida, who has conducted several experiments in this area. "Say you take French eight hours a day for two weeks—language immersion courses yield excellent performance right after the class. However, if you want to know French in the long run, you're much better off spending that same amount of time distributed across a semester or a year." When you space out learning like this, he says, "you can have up to 100 percent more retention."
Sleep On It
Hit the books; then hit the pillow. That will help the brain lock in what you learned. Even naps are beneficial, according to a Harvard study in which subjects who took a 90-minute snooze after learning a task performed 50 percent better over a 24-hour period than the napless group.
"Sleep after learning helps solidify memory," says Susumu Tonegawa, PhD, a Nobel Prize-winning professor of biology and neuroscience at the Picower Institute for Learning and Memory at MIT. According to animal studies, when you perform a task, the brain cells fire in a certain sequence. If you then fall asleep, the same cells automatically fire in an identical sequence without being distracted or disrupted by incoming visual stimuli. That, Tonegawa says, "solidifies the synapses, which in turn helps to strengthen the information as a memory."
Once you've remembered the Spanish word for house or done a math problem correctly, continuing to practice does very little for long-term retention, says Rohrer. "Study a lot of material for a little bit of time in one session, rather than a little bit of material for a lot of time."
Keep Your Brain Fit
The long-held assumption that we lose about 10 percent of our neurons per decade is not true. "Remarkably, there are as many neurons in a healthy 80-year-old brain as there are in a young adult's," says Michela Gallagher, PhD, professor of psychological and brain sciences at Johns Hopkins University. "When you're 50 or 60 and forget something, you think, 'Oh my God, my brain's falling apart.' But if you've still got all your neurons, the likelihood that you can prevent memory loss is much greater than if your brain had substantially deteriorated."
The magic memory pill has yet to be found, but science does know that regular exercise, social engagement, and education all help keep the brain sharp as you age—"not just in terms of current memory," says Gallagher, "but also in reducing the risk of Alzheimer's disease."