This article by Jeff Wilson was found on the Tricycle Blog:

One aspect of aging that many Japanese greatly fear is memory loss. To combat this scourge, a number of Buddhist options have appeared. A popular one is pillow covers blessed by Buddhist monks to ward off dementia. These items are purchased at temples and taken home to be put on your bed pillows. As you sleep on them, the power of the Dharma helps ward off senility and other mental problems. Perhaps this is the religious equivalent of students putting their textbooks under their pillows so they'll pass a test the next day.
The Japan Times carried a story about another strategy. Some temples, such as Honjuin, a Tendai temple in Tokyo, offer Sutra copying to visitors in order to prevent memory loss. This is an ancient practice: laypeople have been sponsoring the copying of Sutras or doing it themselves for centuries in an effort to bring about all sorts of results, medical and otherwise. But now there seems to be some science to back the practice up. Dr. Kawashima Ryuta of Tohoku University discovered that copying Sutras promotes brain activity in senior citizens.

Want to try it out yourself? You don't even have to go to temple. Higashi Honganji, one of the largest Buddhist denominations in Japan, offers English-speakers the chance to copy a holy text online. Technically, it's a commentary, not a Sutra, though the text itself (Tannisho) is revered above many Sutras in the Jodo Shinshu tradition. Higashi Honganji doesn't promise memory retention, only that it can help settle your mind.

Jeff Wilson is a contributing editor to Tricycle magazine and the web site, Killing The Buddha. A Ph.D. candidate in Religious Studies at the University of North Carolina at Chapel Hill, he is dual-trained in Buddhist Studies and American Religious History. Jeff is a certified Lay Teacher in the Jodo Shinshu Buddhist tradition.