As students return to classes after summer break, they may be finding it tough to get back into learning mode. Later in life, we may come up against similar challenges with learning and memory.
We asked experts across campus — including neuroscientists, psychologists, a nutritionist and a physical education expert — for their best, research-based advice for staying mentally sharp throughout life. Daniel Johnston, director of the university's Center for Learning and Memory, says the question he gets asked most at public talks is, "How can I prevent age-related memory loss?" Here are Johnston's six tips:
There might be something to that old ad campaign describing coffee drinkers as "coffee achievers."
"Caffeine is the only drug consistently shown to have positive effects on attention, memory and learning," says Ali Preston, associate professor of neuroscience and psychology.
She says caffeine works its brain-boosting magic by heightening your arousal. That's important because to form new memories, you have to pay attention. A 2014 Johns Hopkins study found that people remember images they saw the day before better if they take a caffeine tablet a few minutes after they first see the images. Other studies have suggested that caffeine lowers the risk of Alzheimer's, including a study of mice given caffeine in their drinking water and a Finnish study of 1,400 human coffee drinkers, both in 2010.
But to get the most benefit, says Preston, dosage is key. When your brain is too highly aroused, you pay equal attention to things that matter and things that don't. Too much coffee close to bedtime can also deprive you of sleep, and sleep is important for healthy brain function. For most people, a couple of cups of coffee a day leads to the sweet spot where you have heightened attentiveness to the right things, but not so much that it interferes with sleep and makes it hard to concentrate.
Sleep is the Swiss army knife of memory and learning. During sleep your brain:
- consolidates memories, encoding them in the connections between neurons, making them easier to recover
- strips away unimportant details, so that what you remember is more useful
- solidifies skills you've learned (you actually continue learning the material after you've shut the book and gone to bed)
- flushes out harmful toxins that accumulate during the day, which might otherwise increase your risk of Alzheimer's disease
- builds up stores of reserve energy for times when you have to think real hard
- develops the ability to focus and avoid distractions the next day
So what's the best way to sleep for optimal brain function? According to Art Markman, psychology professor, set a routine. Pick a consistent time to go to sleep and do things before bedtime that remind your body it's time to go to sleep, such as turning off the TV or computer, taking a bath and turning the lights down. Research shows that most people need about eight hours of sleep a day, plus or minus a half-hour. Teenagers need even more.
"That's why sometimes you have to set off a small thermonuclear device under their beds to get them up," Markman quips.
According to Lydia Steinman, a registered dietician and distinguished senior lecturer in nutritional sciences, a diet that's good for your body is also good for your brain. After all, your brain is part of your body.
She acknowledges that there is still a lot of conflicting research about which foods are best for you and which you should avoid. But her general advice is to eat a diet rich in plant-based foods — a variety of vegetables, fruits, whole grains and small amounts of nuts and seeds — which are excellent sources of vitamins, minerals and fiber. Supplement those with lean meats and low-fat dairy products, which are also high in nutrients. She also recommends avoiding sugary soft drinks because they have a lot of calories without the beneficial nutrients that you would get from other foods and drinks.
Finally, she notes that getting enough calories is important for mental concentration. So, if you're a student and you want to perform at your best, don't skip breakfast.
"I want students to know that by following an adequate, balanced, varied and moderate diet, you can achieve health," she says. "It's that simple."
Exercise Your Body
According to Darla Castelli, associate professor of physical education, when you engage in aerobic exercise, the blood flow to your brain is reduced. But after you stop, you get a rush of oxygenated blood to the brain that's higher than normal. That extra flow makes you more alert and focused. Castelli is conducting research to see how short bouts of exercise might help students learn better. Studies also show that regular exercise can make you better at solving problems, faster at processing information and faster at switching from one mental task to another.
Scientists have also discovered that when mice exercise (say, by taking a spin in a running wheel), the part of their brains that is most responsible for memory, the hippocampus, grows new neurons, and the mice have higher levels of brain chemicals that promote survival and growth of neurons. These effects haven’t been confirmed in humans yet, but many neuroscientists, including Michael Drew, assistant professor of neuroscience, think we probably experience the same benefits when we exercise, too.
"All the things that are good for your body — eating right, getting aerobic exercise, and so on — are good for your brain as well," says Drew.
Exercise Your Mind
You might do the New York Times crossword puzzle every day and think you're keeping your mind sharp, but think again.
"Studies in animals tell us you only get effects when the animals are learning something totally new," says Drew. An animal running through a maze for weeks on end will only grow new neurons when it’s first learning the maze. To keep the effect going, you have to switch them to another maze. Studies of elderly people also show that learning new, mentally demanding skills like photography or quilting boosts memory.
"Once you've mastered crossword puzzles," says Drew, "try something in another cognitive domain. Learn a new language or try Sudokus."
According to Jennifer Beer, associate professor of psychology, social interaction keeps your mind sharp. It forces you to multitask — conversations involve staying aware of what the other person is saying, while planning what you’ll say — and it feeds humans’ deep need for social acceptance. (People who have recently experienced rejection have a harder time focusing their attention and remembering things.)
But Beer says simply being social isn't enough to stay sharp. You have to be interacting with others in a way that involves multitasking, problem solving and learning new things. In other words, playing a game of chance like War or watching a movie with others won't give you the same boost as playing a game of strategy like Bridge or discussing a novel.
"Not every social interaction has to be mentally stimulating. That would be stressful," says Beer. "You want a good mix of stimulation and social acceptance."
This story is part of our series "In Pursuit of Health," covering medical news and research happening across the university.